Download PDF: Crown Forklift SSR Pallet Service Manual

INTRODUCTION

This manual is intended for the service mechanic who is seeking information about maintenance and service replacement parts. It contains a section on trouble shooting which will enable a qualified mechanic to locate and solve problems which may occur.

This manual does not contain operation instructions. For operation instructions, refer to the Crown publication, “You and Your Crown Slip Sheet Rider,” PF-3415.

When ordering replacement parts from this manual, always specify, along with the part number, the model and serial number of the truck. This information will further enable us to give correct, fast and efficient service.

For Series SSR capacities, technical information and dimensional specifications, please refer to the following sales literature: Series SSR SF-3322 Copies of publications can be obtained from your Crown dealer or by writing to: Crown 40-44 S. Washington Street New Bremen, OH 45869

An index for this manual is located on the following pages. The manual is arranged according to major sections. The first part of the page number, found at the bottom of each page, denotes the section in which a particular form will be located. These sections are indicated by a black bar at the right hand edge of the page. The higher the number of the section, the farther down the edge it is located. The sectional breakdown is as follows: Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 8 Section 9 Section 10

© Crown 1978 PF-3414

ITD - 12 - 001

Basic Chassis or Power Unit Hydraulic System and Components Drive Unit and Components Electrical Components Brake Systems and Brake Assemblies Steering Systems and Components Cylinders Tilt Carriage Accessories

Printed in U.S.A.

ITD - 12 - 001

INTRODUCTION

All Crown lift trucks are given a model number. This number is used as a brief description of the truck. The following chart gives a model number and shows how it was formed.

EXAMPLE: A truck having the model number 30 SSR is a 3000 lb. capacity stand-up rider with a slip sheet attachment. * Actual rated capacity may vary, depending upon special equipment or modifications. Consult serial number plate.

Printed in U.S.A.

ITD - 12 - 002

ITD - 12 - 002

SAFETY

General Maintenance Instructions

General Maintenance Instructions WARNING An injury could occur.

TO PREVENT SERIOUS RISK OF INJURY TO YOURSELF AND OTHERS OBSERVE THE FOLLOWING SAFETY INSTRUCTIONS Power industrial lift trucks may become hazardous if adequate maintenance is not performed. Adequate maintenance facilities, trained personnel, and procedures must be provided.

Maintenance and inspection must be performed in conformance with the following practices: 1. A scheduled planned maintenance, lubrication, and inspection system should be followed.

2. Only qualified and authorized personnel shall be permitted to maintain, repair, adjust and inspect the lift truck.

3. Before performing maintenance on the lift truck: • Bring the lift truck to a complete stop.

• Fully lower the load engaging means.

• Put the directional control in neutral.

• Apply the parking brake.

• Turn off the lift truck.

• Remove the key.

• Chock the wheels of the lift truck.

• Raise the drive wheel off the floor or disconnect power sources.

• Use chocks or other positive positioning devices.

• Block the load engaging means, inner masts, or chassis before working under them. When working in these areas keep hands, arms, feet, and legs clear to prevent pinching or injury.

• To check the performance of the lift truck and attachments, move the lift truck to a secure non-traffic maintenance area with a level floor and adequate clearance.

4. Before operating the lift truck: • Be in the proper operating position.

• Apply the brake.

• Put the directional control in neutral.

Crown 1976 PF2821 Rev. 6/22

•

Make sure to check the functions of the lift systems, directional control, speed control, steering, warning devices, brakes, and attachments, if any are used.

5. Avoid fire hazards and have fire protection equipment present. Do not use an open flame to check level, or for leakage of electrolyte and fluids or oil.

Do not use open pans of fuel or flammable cleaning fluids for cleaning parts.

6. Keep the maintenance area well-ventilated, clean, and dry.

7. A tip-over can occur with the improper use of this lift truck, even when the forks are unloaded. In the event of a tip-over, do not jump from the lift truck.

Hold the steering wheel tightly and brace your feet.

8. The brakes, steering mechanisms, control mechanisms, lift overload devices, guards, and safety devices must be inspected regularly and maintained in a safe operating condition.

• All guards must be installed to the factory configuration and condition before operating the lift truck.

Do not operate the lift truck if any guards or fasteners are damaged, improperly installed, or missing.

9. The capacity, operation, and maintenance instruction plates or decals must be maintained in legible condition.

10. All the parts of the lifting mechanisms must be inspected to maintain them in safe operating condition.

11. All hydraulic systems must be regularly inspected and maintained in conformance with good practice.

The cylinders, valves, and other similar parts must be checked to make sure that drift has not developed to the extent that it would create a hazard.

12. Batteries, motors, controllers, limit switches, protective devices, electrical conductors, and connections must be maintained in conformance with good practice. Provide close attention to the condition of electrical insulation.

13. Keep the lift truck clean to minimize fire hazard and facilitate detection of loose or defective parts.

14. Modifications and additions that affect capacity and safe lift truck operation must not be performed by the customer or user without the manufacturer’s prior written approval. The capacity, operation and maintenance plates or decals are to be changed accordingly.

• Adding electrical devices (radio, terminal, lights, etc.) or changing existing components or wiring can MA-04.0-001 07 Rev. 6/22

3

SAFETY

General Maintenance Instructions affect the lift truck operation and could cause an accident. Contact an authorized Crown personnel before adding to or changing the electrical system.

Technician Tips: In North America, for EE-rated lift trucks, adding electrical devices could cause a fire or explosion, as well as void the EE rating. Written approval must be obtained from Crown prior to adding electrical device(s). Prior to use, inspection of installed device(s) must be performed by an appropriate nationally recognized testing laboratory (i.e. Underwriters Laboratories Inc) or the Authority Having Jurisdiction (see NFPA 505).

15. Make sure that all replacement parts are interchangeable with the original parts and of equal quality to the original equipment.

16. Make sure that any equipment added to the lift truck (terminal, fan, clipboard, etc.) is positioned so that it does not block your vision or interfere with safe and efficient operation of the truck.

Technician Tips: For more information about operation and maintenance procedures: • For all lift trucks, except, Series B and tow tractors, see ASME B56.1.

• For Series B lift trucks, see ASME B56.10.

• For tow tractors, see ASME B56.9.

Technician Tips: For European lift trucks, for more information about operation and maintenance procedures, see the F.E.M. safety code - Power Industrial Truck (section 4).

For copies send to: F.E.M 10 Avenue Hoche 75382 Paris Cedex 08 France

MA-04.0-002 07 Rev. 6/22

4

Crown 1976 PF 2821 Rev. 6/22

SAFETY

Cleaning of Material Handling Equipment

Cleaning of Material Handling Equipment Cleaning procedures Using dry, pressurized air and solvent • Clean the contamination from the material handling equipment with dry, pressurized air.

• Remove the grease from the material handling equipment with the applicable solvent.

Using a power washer

CAUTION

Make sure that these components are safe and correctly lubricated after cleaning.

• Be careful when using a power washer on metal surfaces.  When using a power washer, remove the paint and protective cover from components (hydraulic lines, terminal strips, and linkages) in a freezer condition environment.  Apply paint or protective cover to these areas to decrease the risk of corrosion.

• Before installing the removed components, or lubricating, or operating the equipment, make sure that the equipment does not contain solvent and is dry.

See the Crown Cleaning Products table for items used to clean the material handling equipment.

Material damage can occur.

If the above procedures are not satisfactory and you must use a power washer, be careful that you do not do damage to the lift truck.  The electrical components (connectors, terminal boards, and wires) can be permanently damaged from water or solvents.  Contamination on or in these components after you use a power washer can cause corrosion: • The circuit boards • The contactors • The encoders • The switches • The potentiometers •

Event codes and irregular lift truck operation can occur if using a power washer.

• Make sure that all the electronic components are safe from the power washer.  Removing the components is the best procedure to decrease the risk of damage.

• When a power washer is used, remove the lubricants in or on the surface of the following components: – Shafts – Bearings – Hinges – Gears – Bushings – Chains – Linkages

Crown 2000 PF11969 Rev. 9/21

MA-1140-050 05 Rev. 9/21

5

SAFETY

Cleaning of Material Handling Equipment Crown Cleaning Products Cleaner Type

Part Number

Package Quantity

Degreaser and cleaner

363105-001 363105-012

19 oz can (12) 19 oz cans

All-purpose cleaner

363114-001 363114-012

19 oz can (12) 20 oz cans

Glass cleaner

363101-001 363101-012

19 oz can (12) 19 oz cans

Waterless hand cleaner

363111-001 363111-012

15 oz tube (12) 15 oz tubes

Pumiced and smooth hand cleaner

363112-001 363112-004

1 gal jug (4) 1 gal jugs

Wall-mounted deluxe soap dispenser

363122

Use with P/N 363112-001

Tough on grease

063009-005

1 gal jug

Citrus degreaser spray

363156-001 363156-012

32 oz spray bottle (12) 32 oz spray bottles

Citrus degreaser spray

363157-101 363158-101

1 gal refill (use with P/N 363134-001) 1 gal concentrated (use with P/N 363134-001)

Citra-sol degreaser

363146-001 363146-012

19 oz can (12) 19 oz cans

Battery cleaner

363124-001 363124-012

18 oz can (12) 18 oz cans

MA-1140-051 05 Rev. 9/21

6

Crown 2000 PF11969 Rev. 9/21

MAINTENANCE LUBRICATION

The use of high grade lubricants and fluids should be used. Sources of these lubricants may be from almost any of the oil companies; those listed below are typical and any lubricant with equal specifications may be used.

(See Chart 1-1)

To obtain maximum life of any industrial equipment, a well planned maintenance program should be followed.

The following information is intended to provide guidelines for proper lubrication intervals as called out in the lubrication chart, however, some operating conditions will require more frequent checks and lubrication than listed. For example, applications with much dust or moisture will require modification of the schedule to fit that particular application.

†

On trucks equipped to operate in below freezing temperatures, low temperature hydraulic oil must be used.

* Denotes allowable substitutes Contact factory if unavailable CHART 1-1

© Crown 1978 PF-3453-1

M1.0 - 12 - 001

Printed in U.S.A.

M1.0 - 12 - 001

MAINTENANCE LUBRICATION CHART

See Chart 1–3 for lube type designation explanation. † - Check

C - Change

L - Lubricate

AR - As Required

CHART 1-2 Refer to Illustrations 1-1 and 1-2.

LUBE TYPE CHART

* Trucks used in below freezing temperatures must use Low Temp. Hydraulic Oil CHART 1-3

© Crown 1978 PF-3453-2

M1.0 - 12 - 002

Printed in U.S.A.

M1.0 - 12 - 002

MAINTENANCE

ILLUSTRATION 1-1

© Crown 1978 PF-3453-3

M1.0 - 12 - 003

Printed in U.S.A.

M1.0 - 12 - 003

MAINTENANCE

ILLUSTRATION 1-2

© Crown 1978 PF-3453-4

Printed in U.S.A.

M1.0 - 12 - 004

M1.0 - 12 - 004

MAINTENANCE INSPECTION AND ADJUSTMENT CHART

CHART 1-4 Refer to Illustrations 1-1 and 1-2.

© Crown 1978 PF-3453-5

Printed in U.S.A.

M1.0 - 12 - 005

M1.0 - 12 - 005

INSPECTION & LUBRICATION SAE Torque Values

SAE Torque Values It is important to tighten fasteners to the correct torque value. This section shows the standard torque values for the screws and bolts used in Crown lift trucks and vehicles. Special torque values in the maintenance and parts sections of this manual override the standard torque values in this section.

Grade

Grade Identification (on Head)

Specification

Bolt and Screw Size (in)

SAE - Grade 2

1/4 through 1-1/2

SAE - Grade 5

1/4 through 1-1/2

SAE - Grade 8

1/4 through 1-1/2

NOTE: Even though a bolt head is unmarked, Crown uses nothing less than Grade 5 in all its bolted assemblies. Instances do occur when Grade 5 bolts are manufactured unmarked. When a fastener is replaced that is unmarked, replace the fastener with a Grade 5.

Fig. 1 (14916-02)

Crown 1979 PF5067 Rev. 2/16

M1.9-14.0-001 06 Rev. 2/16

71

INSPECTION & LUBRICATION SAE Torque Values

Torque Chart Bolt Diameter

Grade 5

Grade 8

Dry Torque Specification

Dry Torque Specification

in

ft Ib

kg-m

Nm

ft lb

kg-m

Nm

1/4

9±3

1.2 ± 0.4

12 ± 4

13 ± 4

1.8 ± 0.5

17.5 ± 5.5

5/16

18 ± 5

2.5 ± 0.7

24.5 ± 7

25 ± 5

3.5 ± 0.7

34 ± 7

3/8

32 ± 5

4.4 ± 0.7

43.5 ± 7

48 ± 10

6.6 ± 1.3

65 ± 13.5

7/16

50 ± 10

6.9 ± 1.4

67.5 ± 13.5

75 ± 10

10.4 ± 1.4

102 ± 13.5

1/2

75 ± 10

10.4 ± 1.4

101.5 ± 13.5

112 ± 15

15.5 ± 2.0

152 ± 20.5

9/16

110 ± 15

15.2 ± 2.0

149 ± 20.5

163 ± 20

22.5 ± 3.0

221 ± 27

5/8

150 ± 20

20.7 ± 2.8

203.5 ± 27

225 ± 30

31.1 ± 4.1

305 ± 41

3/4

265 ± 35

36.6 ± 4.8

359 ± 47.5

400 ± 50

55.2 ± 6.9

542 ± 68

7/8

420 ± 60

58.1 ± 8.3

569 ± 81

640 ± 80

88.3 ± 11.0

868 ± 108

1

640 ± 80

88.5 ± 11.1

868 ± 109

960 ± 115

132.5 ± 15.9 1300 ± 156

1 1/8

800 ± 100

110.6 ± 13.8 1085 ± 136

1 1/4

1000 ± 120

138 ± 16.6

1356 ± 163

1 3/8

1200 ± 150

166 ± 20.7

1630 ± 203

1 1/2

1500 ± 200

207 ± 27.7

2034 ± 271

Torque specifications for bolts related to hydraulic valves.

5/16

13 ± 2

1.8 ± 0.3

17.5 ± 2.5

3/8

24 ± 2

3.3 ± 0.3

32.5 ± 2.5

7/16

39 ± 2

5.4 ± 0.3

53 ± 2.5

NOTE: Special torque values in the maintenance and parts sections of this manual override the standard torque values in this section.

M1.9-14.0-002 06 Rev. 2/16

72

Crown 1979 PF5067 Rev. 2/16

MAINTENANCE HYDRAULIC SYSTEM The hydraulic system in your truck is powered by a gear type pump which supplies the hydraulic pressure for the lift, tilt, side shift, push-pull and clamp cylinders.

Maximum pressure for these cylinders is limited by relief valves. Typical relief valve settings are noted on the hydraulic schematic (Illustration 2-23).

The following is a general description of the system as shown in Illustration 2-23, which is typical of current standard units (your unit may vary – see appropriate schematic elsewhere in this manual.)

The hydraulic oil is drawn from the reservoir, through the suction line, by the pump and motor (Item 1). Pressurized oil from the pump then enters the control valve (item 2).

The control valve is a four spool, closed center, self centering, manually operated valve having internal draining and an integral relief valve. The relief valve is located in front of the first spool. When the lift control valve lever is in the lift position, the first spool shifts and the oil is directed out the face of the valve and through the flow control valve (item 6) unrestricted. The oil then enters the lift cylinder (item 7). Any oil that escapes past the piston is removed from the rod end of the cylinder and is directed back to the reservoir. When the control valve is positioned for lowering, the first spool shifts, allowing the oil in the cylinder to return to the reservoir. This directs the oil back through the flow control valve, which meters the oil back to the reservoir, controlling the cylinder’s rate of descent. The oil is filtered when it returns to the reservoir by means of a 10 micron filter (item 11).

of the clamp cylinders and the rod end of the push-pull cylinders. Due to the unequal working areas of the cylinder pistons, the clamp cylinders will fully extend (clamp) before the push-pull cylinders begin to retract. The existing oil in the cylinders is expelled and filtered as it returns to the reservoir.

To activate the tilt cylinder (item 4), the third spool is shifted by the control lever. When the tilt control lever is in the tilt back position, the oil is directed through the tilt valve (item 3), which contains a holding valve, relief valve and a check valve and on to the rod end of the tilt cylinders. Once the cylinder is fully retracted, the relief valve dumps the excess oil back to the reservoir until the lever is returned to neutral. The holding valve blocks any oil from escaping from the rod end of the cylinder. When the lever is put in the tilt forward position, a pilot line from the cylinder cap end line shifts the holding valve, allowing free flow from the rod end of the tilt cylinder to the reservoir. The check valve prevents the load on the rod end (forks) from actuating too rapidly.

When the side shift lever is positioned to shift right, the spool allows the oil to travel to the cap end of the side shift cylinder (item 10). Once the cylinder is fully extended, the relief valve located in the cross valve (item 9) opens on the pressure line and dumps the excess oil back to the reservoir. When positioned for side shift left, the oil enters the rod end of the cylinder and when fully extended, is relieved back to tank.

The second spool in the control valve activates the pushpull and clamp cylinders (item 8) located on the slip sheet assembly. The push-pull and clamp operations can be performed by means of either the push-pull lever or push buttons located on the control pod. The push buttons activate an independent solenoid operated control valve (item 5) which ties in to the hydraulic lines just beyond the four spool control valve. When the push-pull control lever is in the extended position or when the extend push button is depressed, the appropriate spool shifts and directs the oil through a sequence valve located on the slip sheet assembly. The sequence valve directs the oil to the rod end of the clamp cylinders. When the clamp cylinders are completely retracted, the sequence valve shifts and directs the oil into the cap end of the push-pull cylinders. Once the push-pull cylinders are extended to the desired position, the push-pull control lever must be returned to the neutral position. Upon positioning of the push-pull control lever in the retract position, the spool shifts and directs the oil to the junction block in front of the sequence valve, which routes the oil to the cap end

ILLUSTRATION 2-23

© Crown 1978 PF-3454

M2.0 - 12 - 001

Printed in U.S.A.

M2.0 - 12 - 001

MAINTENANCE RESERVOIR With all cylinders in the retracted position and after all air is bled, level of oil in reservoir is to be between 1/2 to 11/2″ above bottom screen of fill strainer.

Use only a good grade of hydraulic oil such as Union Oil AW 150 (Crown No. 63001-1) or equal. On trucks equipped to operate in below freezing temperatures, Petro Fluid #606 or equal is recommended (Crown No. 63001-6)

HYDRAULIC LINES AND FITTINGS 1. Blow air through all hose and lines to remove loose particles before installing. Any rubber hose with wire braid inner construction and any steel tube lines which have been collapsed or kinked are permanently damaged and must be replaced even if the damage is not externally visible.

2. Flexible hose shall be replaced if it collapses in its normal operating position.

3. All hoses and lines are to be clear of any surface or edge which will cause damaging wear and cuts, or on which they can become caught.

4. All connections are to be leak free.

5. Spring sleeving is used around several hydraulic hoses on the slip sheet assembly. When replacement is necessary, spring sleeved (guarded) hoses must be used.

FILTER The spin on filter cartridge has been tightened by Crown.

When replacing filter, apply a film of oil 63001-1 to the seal and hand tighten until seal snugly contacts filter head.

CAUTION

Do not tighten filter with the use of a wrench. A wrench should only be used for removal of the filter.

NOTE Do not use hydraulic brake fluid.

DRIFT TEST All drift test should be conducted with a capacity load (refer to serial plate for the rated capacity of your truck).

The material used for the test load must be evenly stacked within the limits of a four foot square pallet and must be secured to the fork carriage with the forks spread to their maximum width.

NOTE The lift measurement is to be taken from the tip of the fork to the floor.

CAUTION

Never stand or work under suspended load.

Elevate the test load approximately two feet and shut off the truck. After five minutes, measure the distance the forks have drifted. Drifting in excess of 1/2″ per minute, over a period of five minutes (21/2″ total drift) is considered unacceptable. The five minute duration of this test is necessary due to the centering time required for the control valve spool.

Occasionally, a slight creep of the fork assembly may occur due to internal leakage in the piston pak, but it can also be caused by leakage in the check or control valve.

To seat these valves properly when this occurs, raise and lower the forks to flush out any foreign material from the valve seat.

A thorough check for leaks in the system should be conducted if abnormal oil losses occur. The hydraulic system is designed to eliminate mechanical damage even if fittings become loose.

Printed in U.S.A.

M2.0 - 12 - 002

M2.0 - 12 - 002

HYDRAULIC Hydraulic Schematic Symbols

Hydraulic Schematic Symbols VENTED RESERVOIR with the lines above the fluid level

VENTED RESERVOIR with the lines below the fluid level

FILTER or STRAINER

HYDRAULIC PLUMBING with full flow (this includes tubes, hoses, and the flow paths in the manifolds)

PILOT or DRAIN LINE limited flow

LINES CROSSING

M

ELECTRIC MOTOR operates in one direction and speed

M

ELECTRIC MOTOR operates in one direction in a speed that changes

M

ELECTRIC MOTOR operates in two opposite directions in a speed that changes

HYDRAULIC PUMP fixed displacement, operates in one direction

HYDRAULIC PUMP-MOTOR fixed displacement, operates in two opposite directions in a speed that changes

HYDRAULIC MOTOR operates in two opposite directions

LINES CONNECTED GAUGE pressure QUICK DISCONNECT (disconnected)

PLUGGED PORT (test port)

FLOW METER

GAUGE temperature

ACCUMULATOR gas charged, diaphragm type

Fig. 1 (3559-05) Crown 1979 PF5066-1 Rev. 6/12

M2.1-00.0-001 07 Rev. 6/12

169

HYDRAULIC Hydraulic Schematic Symbols

PRESSURE SWITCH

CYLINDER double-acting cylinder, unequal area

CYLINDER double acting cylinder, equal area (steer) (two end)

ACTUATOR MANUAL

SPRING (spring-bias in the de-energized position)

SOLENOID one coil or winding

CYLINDER single-acting cylinder with spring return (the rod end has a vent) HYDRAULIC PILOT OPERATED CYLINDER single-acting cylinder, ram type SOLENOID pilot operated

CYLINDER single-acting cylinder, with cushion SOLENOID DUAL

COMPONENT ENCLOSURE manifold block

ACTUATOR MANUAL LEVER

SOLENOID PROPORTIONAL

VALVE PILOT CHECK (pilot to open)

Fig. 2 (3560-05) M2.1-00.0-002 07 Rev. 6/12

170

Crown 1979 PF5066-2 Rev. 6/12

HYDRAULIC Hydraulic Schematic Symbols

ORIFICE THROTTLE fixed

VALVE SHUTTLE

ORIFICE THROTTLE adjustable VALVE SINGLE COUNTERBALANCE in manifold

FLOW CONTROL PRESSURE COMPENSATED fixed

FLOW CONTROL PRESSURE COMPENSATED fixed with reverse flow bypass

FLOW DIVIDER/COMBINER

FUSE VELOCITY BYPASS FLOW CONTROL controlled flow, pressure adjusted

VALVE RELIEF fixed

VALVE RELIEF adjustable

VALVE CHECK

VALVE MANUAL SHUTOFF

P T

T P

TORQUE GENERATOR

L R

STEER UNIT hydrostatic

Fig. 3 (3561-05) Crown 1979 PF5066-3 Rev. 6/12

M2.1-00.0-003 07 Rev. 6/12

171

HYDRAULIC Hydraulic Schematic Symbols

VALVE two-way valve with two positions

VALVE three-way valve with two positions spring-bias, solenoid control

VALVE three-way valve with two positions

VALVE four-way valve with two positions

VALVE four-way valve with three positions two spring centered, manual lever control

VALVE four-way valve with three positions

VALVE two-way valve with all positions

NOTE: The type of valve is the number of spools found in the component (the three spool valve is above)

VALVE four-way valve with all positions

Fig. 4 (3562-04) M2.1-00.0-004 07 Rev. 6/12

172

Crown 1979 PF5066-4 Rev. 6/12

MAINTENANCE

ILLUSTRATION 2.1-1 HYDRAULIC PUMP — PARKER HANNIFIN

Preparation for Disassembly

Pump - Gear

The pump overhauling should be performed in a clean, dust-free location, using clean tools and equipment. Dirt or grit will damage the highly machined surfaces and will result in leakage or premature failure of the pump.

Before the pump is removed or disassembled, check the following list of common troubles and remedies. It could save time, effort and money.

Crown 1982 PF-5361-1 Rev. 4/88

Printed in U.S.A.*

02 REV. 4/88

M2.1 - 07.2 - 001

M2.1 - 07.2 - 001

MAINTENANCE Pump Disassembly

One gear assembly may be replaced separately if the other is in good condition.

NOTE 2.

All item numbers refer to their respective parts on the exploded view (Illustration 2.1–1).

1. Clean unit thoroughly with solvent, kerosene or other non-corrosive cleaning fluid, which will not affect rubber components.

Replace the shaft seal (11) only if it shows excessive wear or cracking.

2. Scribe a line across the three sections of the pump to act as a guide in reassembly.

Check all internal threads for damage.

3. Remove the four hex screws.

Bearings must be below the cover faces and show no signs of contact with snap rings on gear shafts.

4. Remove the front cover (10) by lightly tapping the flange with a soft metal hammer.

5. The center section (9) will remain attached to either the front cover (10) or back cover (1). Place the drive gear (4) into the unseparated sections, and while holding the center section (9), tap lightly to separate.

Be careful to avoid cocking on the dowel pins.

6. Remove wear plate (5).

7. Mark the front cover island next to the pressure vent hole in the heat shield (6), gasket (7), and V-seal (8) to act as a guide in reassembly. The location of this vent hole determines pump rotation.

8. Use a small diameter wire (a paper clip will do) to remove the phenolic heat shield (6), the paper compound gasket (7) and the rubber “V” seal (8). Discard these parts and replace when pump is reassembled.

9. Remove both “O” rings (2) and discard. They also should be replaced.

10. Do not remove shaft seal (11) in the front cover (10) unless it is damaged or leaking. If seal is to be replaced, use great care not to damage the seal recess or bearing. Heating the cover in an oven to 250° F (121° C) will reduce the press fit.

11. If R/V is defective, replace as complete R/V unit.

Part Inspection, Evaluation and Replacement 1. DRIVE (item 4) AND DRIVEN (item 3) GEAR ASSEMBLIES–Inspect shafts for roughness in the bearing and sealing areas. Measure for wear.

Minimum acceptable .4998″ (12.695mm) with a 5J surface finish maximum.

Inspect the gear end faces, outside diameter and teeth for roughness and score marks. The O.D. of the “D” gears must be 1.2395″ (31.483mm) minimum, minimum gear widths should be .5412″ (13.747mm).

FRONT COVER (item 10) AND BACK COVER (item 1) ASSEMBLIES–If any bearing bore diameter exceeds .5015″ (12.738mm) in the “D”, the cover should be discarded. Bearings are not supplied separately.

If bearings are scored, rough, or show signs of heat discoloration, the cover assemblies should be replaced.

3. CENTER SECTION (item 9)–Inspect the wall of gear bore diameters for excessive wear or score marks.

The center section gear bores will show signs of wear on the inlet side of the pump. A wear ridge will develop at the end of the gear bore where the thrust plate is located. This wear ridge should not exceed 1/32″ (0.794mm).

Lightly lap the faces to remove any nicks or burrs. Do not break inside edges.

4. WEAR PLATE (item 6)–Inspect bronze wear surfaces for excessive roughness or heat discoloration.

If wear ridges exceed .0005″ (0.013mm), discard and replace.

5. GENERAL–The following parts should be replaced at every major overhaul: Wear Plate (item 5), Fiber Heat Shield (item 6), Paper Gasket (item 7), “V” Seal (item 8) and “O” Rings (item 2). The shaft seal (item 11) should be replaced only when necessary.

Pump Reassembly 1. All parts must be thoroughly cleaned prior to reassembly by dipping in solvent and brushing to remove all traces of contamination. Pump should be assembled in a dirt free area.

2. Install shaft seal (11), if it was removed in front cover with the spring loaded lip facing inward. Force seal into place, using a flat steel rod slightly smaller in diameter than the O.D. of the seal. This will permit the tool to enter the seal recess and bottom the rotary seal on the stop. [The front cover (10) must be backed up on a smooth, clean surface to prevent damaging its face].

Be sure snap rings are secure; break any sharp edges on the sides of the gears.

Gears and shafts are available only as assemblies.

Crown 1982 PF-5361-2 Rev. 4/88

The load to force seal into place should be applied exactly in line with the housing seal bore to prevent bending the seal steer retainer, and/or scoring the seal housing bore.

Printed in U.S.A.*

02 REV. 4/88

M2.1 - 07.2 - 002

M2.1 - 07.2 - 002

MAINTENANCE

3. Install the “V” seal (8), the gasket (7), and heat shield (6) into the front cover cavity as follows:

7. Check wear plate to insure it is still seated into its oval cavity and install the center section (9) over the gears until it engages the wear plate. Center section must be positioned so that the previously scribed lines on the housing exteriors are in line with those scribed on the front cover. The small slot located midway between the bores should align with the small vent hole in wear plate. The face containing the slot shall be in contact with the wear plate.

The small vent hole through all of these parts shall be in line and positioned next to the scribe mark on the island previously made during disassembly. This position locates the vent holes on the outlet side of the pump.

The lips on the “V” seal shall face toward the cavity and be tucked into the groove with the aid of a dull tool to prevent damage to the rubber surface.

A small screwdriver can be used.

The gasket shall be pressed firmly toward the bottom of the cavity with the thumbs so as to insure all of its perimeters are completely within the groove to avoid interference with subsequent assembly.

The heat shield shall be firmly pressed toward the bottom of the cavity with the thumbs to provide sufficient space for the wear plate.

4. Install “O” Ring (2) into the groove provided in front cover face. Oil the “O” Ring and stretch it slightly, if necessary, so that it will remain in its groove.

5. Install the wear plate (5) with the bronze surface against the gears and the small vent hole in line with the hole in the heat shield. Press the wear plate. The wear plate shall be sufficiently within the oval cavity so that it is axially retained.

6. Install drive gear (4) and driven gear (3) assemblies into the front cover. Apply oil to the shaft at the drive end to prevent damage to the shaft seal caused by sharp edges on the drive shaft passing through the shaft seal. An oil coated shaft, rotated slowly, will usually cause no damage to the seal.

Check to see that the shaft seal lip and spring is not pushed out by the shaft.

Then install dowel pins and add a generous amount of clean oil into the gear cavities. Rotate gears to distribute the oil.

8.

Install “O” Ring (2) into its back cover face groove.

Oil the “O” Ring, the cover face, and the bearings.

Install the back cover so that the scribe marks are in line with the marks on the center section and front cover.

9.

The housing retaining screws shall be alternately tightened to 190-210 in. lbs. (21-24 Nm) on the “D” Series.

Add a generous amount of clean oil into both parts to insure the pump is adequately lubricated. Rotate the drive shaft to distribute the oil and check for freedom of shaft rotation. Shaft shall be free to rotate with the help of a short wrench. [100 in. lbs.

(11 Nm) maximum].

Pump Testing After pump has been re-installed, run for 2 – 3 minutes before pressurizing. Try to apply pressure gradually for an additional 5 minutes, but do not pressurize for longer than 5 seconds at a time.

Crown 1982 PF-5361-3 Rev. 4/88

Printed in U.S.A.*

02 REV. 4/88

M2.1 - 07.2 - 003

M2.1 - 07.2 - 003

MAINTENANCE

ILLUSTRATION 2.1-24

PUMP - GEAR Preparation for Disassembly The pump overhauling should be performed in a clean, dust-free location, using clean tools and equipment. Dirt or grit will damage the highly machined surfaces and will result in leakage or premature failure of the pump.

Before proceeding with the pump disassembly, scribe match marks on the stator (item 12) and the gear housing (item 3) to insure that the pump will be reassembled in the same manner as it was shipped from the factory. If the stator or gear housing is replaced during overhaul, scribe a match mark on the new part in the same location as on the part it replaces.

Pump Disassembly NOTE All item numbers refer to their respective parts on the exploded view (Illustration 2.1 -24).

Clean the outside of the pump with a good grade solvent and thoroughly dry. Secure the unit in a vice (using light clamping pressure) at the area of the mounting flange (“A”). Loosen and remove the eight (8) assembly screws (items 1 and 2). Separate the gear housing (item 3) from the stator (item 12). It may be necessary to lightly tap the sides of the housing to facilitate the separation.

CAUTION

Never insert a screwdriver or other similar instrument between the housing and the stator for the purpose of prying the two halves apart as permanent damage may result.

Once the housings are separated, remove the dowel pins (item 11). Also remove the idler gear and drive gear assemblies which includes the retaining rings (item 6), the gears (item 7), the keys (item 8) as well as the idler shaft (item 10) and the drive shaft (item 9). When removing the plastic shim, located between the gear housing face and the stator face, note the color of the shim. These shims are supplied in different colors which corresponds to different thicknesses. When replacing the shim, the same color shim must be reinstalled as was removed. Further disassemble the shaft assemblies and place all components in the solvent.

Part Inspection, Evaluation and Replacement Thoroughly wash all pump components in a good grade solvent and blow dry. Lay the cleaned components on a dirt-free bench or shop-cloth and individually inspect each part for the symptoms mentioned below: 1. DRIVE SHAFT (item 9) — Inspect the drive shaft for wear or cracking on the tang end of the shaft, grooving on the area of the shaft where the oil seal seats, wear or flaking on the area of the shaft where the needle bearings travel, and metal distortion around the keyway or the retaining ring grooves. If any of these conditions exist, the drive shaft should be replaced.

2. IDLER SHAFT (item 10) — Check the idler shaft for wear or flaking on the area of the shaft where the needle bearings travel and metal distortion around the keyway or the retaining ring grooves. If any of these conditions exist, the idler shaft should be replaced.

Printed in U.S.A.*

Crown 1978 PF-3455.1 Rev. 4/88

02 REV. 4/88

M2.1 - 12 - 011

M2.1 - 12 - 011

MAINTENANCE 3. GEARS (item 7) — Inspect the gears for any signs of galling or metal build-upon the side faces of the gears as well as on the outside diameter of the teeth. If these conditions exist, the gears must be replaced. When replacing gears, always replace both gears as a set.

4. OIL SEAL (item 14) — Check the oil seal rubber for wear, cracks, chips or any other condition that would cause the seal to lose its sealing ability. Should any of these conditions exist, Crown recommends seal replacement. To replace the seal, pry out the old seal being careful not to damage the stator oil seal bore.

Locate and squarely press in the new seal “lip first”.

5. NEEDLE BEARINGS (item 5) — With the use of a new shaft (idler or drive) or a metal rod ground to a dimension of .5000’’/.4997” (12.700 mm/12.692mm) in diameter, inserted into the bearing bores, check for excessive bearing to shaft clearance in the stator bearings as well as the gear housing bearings. Although replacement bearings are available, Crown recommends the replacement of the entire stator and (or) gear housing because bearing wear or damage usually damages the bearing bores.

6. STATOR (item 12) — Inspect the innerface of the stator for signs of scoring, excessive wear or metal build-up. If a slight metal build-up is evident, the stator face can be lapped smooth with the use of a solvent soaked crocus cloth (280 or 320 grit) placed on a flat surface. Care should be taken to remove only enough material to clean up the build-ups. A stator having a scored or worn innerface should be replaced.

ILLUSTRATION 2.1-25 The drive shaft should be installed with the use of a sleeved tool, similar to the tool shown in Illustration 2.1-25. Insert the tool through the new oil seal being careful not to damage the seal’s rubber lip. Once in position, introduce the tang end of the drive shaft into the sleeve bore and slide the shaft to a position where the side of the gear is in contact with the stator innerface. Carefully extract the sleeved tool. insert the idler gear shaft into its respective bore after aligning and meshing the gear teeth properly. Once both shafts are in position, check to make sure the shim is free of the gear teeth. Replace the two (2) dowel pins (item 11) and after aligning the scribed match marks, carefully slide the gear housing in place and install screws. If for some reason the scribe marks are not visible, a check to assure proper asembly is as follows:

7. GEAR HOUSING (item 3) — Inspect the gear housing’s gear pocket face and wall for scoring or excessive wear. If either of the conditions exist, the housing should be replaced.

Hold the pump in a position where you are viewing the outside face of the gear housing (screw heads should be visible). Rotate the pump to a position where the idler shaft is directly below the drive shaft. From that position, the 1/2” (12.7mm) NPTF port should be on your left side.

8. KEYS (item 8) — Check the keys for any cracks or shear marks and replace if necessary.

Pump Reassembly Begin the reassembly by placing the shim (item 4) in position on the innerface of stator (item 12). A thin film of hydraulic oil will help maintain the location of the shim. If a new shim is being installed, make sure the shim’s color corresponds to the color of the shim removed during disassembly. Preassemble the idler and drive gear assemblies by installing the keys (item 8), gears (item 7) and retaining rings (item 6) onto their respective shafts (items 9 and 10).

After you are sure of the positioning, finger tighten the eight (8) assembly screws and check to see that the drive shaft rotates freely. If it does, the screws can be tightened to a torque reading of between 8 and 10 ft. lb.(11 and 13.5 Nm).

Again check to see that the shaft turns freely. Before mating the pump assembly to the motor, lubricate the drive shaft tang and the coupling (item 15) with “Moly” grease (Crown No. 63002-11).

Printed in U.S.A.*

Crown 1978 PF-3455.2 Rev. 4/88

02 REV. 4/88

M2.1 - 12 - 012

M2.1 - 12 - 012

MAINTENANCE CONTROL VALVE – PARKER

ILLUSTRATION 2-7 Description This Parker Control Valve consists of a one-piece body, 1 to 4 operating spools, two check valves for each spool, an adjustable relief valve, and the necessary seals and plugs.

© Crown 1978 PF-3374-1

M2.3 - 11 - 001

The body is constructed of a one-piece casting, cored to contain passages for a series parallel circuit. Body ports are tapped with S.A.E. straight thread “O” Ring connections for leakproof connections and to prevent possible distortion of the body when tightening fittings.

Printed in U.S.A.

M2.3 - 11 - 001

MAINTENANCE The spools are plated for corrosion resistance and contain notches to obtain metering control of the load.

Spools are balanced, radially and axially.

Check valves, provided in each spool, prevent back flow from cylinder ports to inlet port.

An adjustable relief valve is incorporated in the valve to prevent excessive oil pressure in the hydraulic system.

NOTE Replacement valve spools are identified by the use of type and color code markings. The color code indicates the spool size. See Illustration 2-8 for location of markings indicating color code.

Operation (See Illustration 2-7) A source of oil is supplied to the “Inlet Port”. With the spools in the neutral position, the flow of oil is through the bypass or open center side of the circuit to the “Outlet Port”. When a spool is operated to a power position, the open center side of the circuit is closed and the oil flows through the spool check valve to the cylinder port. At the same time the other cylinder port is opened to the “Outlet Port”.

ILLUSTRATION 2-8 Limits of spool travel are charted to aid in determining if the spool is traveling its required distance to a power or float position.

SPOOL TRAVEL CHART

The check valve functions as a load check to prevent the flow of oil back from the cylinder port as a spool is moved into a power position.

When the inlet oil pressure is in excess of the relief valve setting, with the open center side of the circuit shut off, the relief valve plunger is forced off the seat, bypassing the oil to the “Outlet Port”. When the inlet oil pressure drops to less than the relief valve setting, the spring forces the plunger back against the seat.

General VALVE BODY. All component parts of the valve are available for service replacement except the valve body.

If the valve body contains damaged threads, cracks, or deep score marks in the spool bore, the valve is not repairable and should be replaced. Control valves with minor damage to the body may be repairable; factory inspection may be required to determine if repairs are feasible.

VALVE SPOOLS. Valve spools may be replaced if there is no damage to the valve body. When replacement spools are ordered from the factory, the same Color Code, Type Code, Valve Model Number and Serial Number should be included with the order. Spring centered spools are shipped from the factory with the springs assembled.

SPOOL CODE CHART

© Crown 1978 PF-3374-2

M2.3 - 11 - 002

Disassembly 1. GENERAL. Disassembly instructions are given for the relief valve, check valves and the various styles of spools which may be used with this series. Disassembly instructions are supported by illustrations complete with descriptive nomenclature.

To disassemble control valve for a thorough cleaning and inspection, or repair purposes, the valve should be removed from the equipment, and the operation performed on a bench. Thoroughly clean the exterior of the valve before beginning disassembly procedures.

Make certain that spools and check valve poppets are clearly tagged so that when used in reassembly they can be returned to their respective bores. Switching of the parts may cause improper seating and spools to stick or excessive leakage due to increased side clearance.

2. TOOLS. a. No special tools are required for disassembling or assembling the control valve, although those described on the following page may be of help.

Printed in U.S.A.

M2.3 - 11 - 002

MAINTENANCE b. For compressing the spring on spring-centered spools, two (2) retainer plates with bolts and nuts, as shown on Illustration 2-9 may be used. To operate spring compressor, place one retainer plate over the eye end of the spool and against the bottom spring spacer and the other retainer plate against the top spring spacer. Line up holes and install bolts and nuts. Tighten nuts evenly to compress spring sufficiently to allow removal of snap ring. Caution should be exercised as spring is compressed. Unscrew bolts slowly until all spring pressure has been released.

ILLUSTRATION 2-10 4. REMOVE CHECK VALVES. (See Illustration 2-7) Clamp spool in a soft-jawed vise. Insert a pin through the hole in spool end (14) and unscrew, then remove spring and check poppet. Reverse the spool in the vise and unscrew eye (11) and remove spring and poppet.

NOTE “P” spools have a check at the spring end only.

ILLUSTRATION 2-9 c. A sleeve type tool, see Illustration 2-10, can be made for ease in snap ring installation on springcentered type spools. Select a piece of round bar stock approximately 5 inches in length and slightly larger in diameter than the snap ring being installed. Drill a hole in the stock slightly larger than the stud end of the spool. Remove any sharp edges. To use sleeve type tool when ready to install snap ring, compress spring (See Illustration 2-9), then position snap ring on stud end of spool.

Position tool against snap ring and tap rather sharply, with a rawhide mallet, until snap ring is seated in groove.

3. REMOVE AND DISASSEMBLE SPOOLS. On springcentered “D”, “P” and “C” Type (See Illustration 2-7), unscrew and remove spool cap. Then grasp spring end of spool and withdraw from valve body. Clamp spool in a soft-jawed vise, compress spring (See Paragraph 2b and Illustration 2-9), then remove snap ring, outer spring spacer, spring and inner spring spacer from spool.

© Crown 1978 PF-3374-3

M2.3 - 11 - 003

5. REMOVE RELIEF VALVE. (See Illustration 2-7) Unscrew cap (17). Remove spring (25) and poppet (26). Do not remove seat (27). Disassemble parts in cap (17) but do not remove seat (24). Remove “O” Rings from cap.

6. REMOVE BODY PLUGS AND “O” RINGS. After spools, relief valve and check valves have been removed, remove all plugs and “O” Rings from valve body.

Cleaning, Inspection, Repair, and Replacement Wash all parts thoroughly in kerosene or similar solvent.

Inspect the valve body bores and spools for grooves, deep scratches or excessive wear. See that spools fit their respective body bores with a slight hand pressure and without perceptible side clearance. Valve spools may be replaced if there is no damage to the valve body. Replacement spools may be ordered from the factory if the proper Color Code, Type Code, Valve Model Number and Serial Number are included with the order. If the spools are loose, scored or damaged or the valve body has damaged threads, cracks, or scored bores, the control valve should be replaced with a new unit, or if the body damage is minor, it may be returned for factory inspection and repair.

Printed in U.S.A.

M2.3 - 11 - 003

MAINTENANCE Inspect the check valve poppet and its seating face in the spool for grooves or defects which may cause leakage.

Check the poppet for free movement in the bore. If the poppet appears to be faulty, replace with a new one.

Small nicks and grooves can be removed from the poppet seating face in the spool by lapping poppet in seat using a fine grain grinding compound. Wash seat sufficiently to remove all traces of grinding compound.

3. INSTALL RELIEF VALVE. (See Illustration 2-7) Install relief seat in the bottom of the bore. Install poppet assembly with small end towards the seat. Install large spring in inner diameter of the plunger. Assemble parts on cap (17). If new seat (24) is required, press into cap till head is flush with small end of cap. Install screw (18) finger tight against its spring. Screw cap into body and tighten.

Inspect relief valve plunger (26) for wear on seating end.

Inspect pilot plunger (21) for wear on cone diameter. If either shows wear, remove its seat and inspect for ridges, scoring or excessive wear. Replace parts if worn or damaged.

NOTE

Discard all “O” Rings, gaskets and wipers and replace with new parts when reassembling the control valve.

NOTE After parts have been inspected and valve is not to be reassembled immediately, coat reusable parts with hydraulic oil.

Assembly 1. GENERAL. Prior to reassembly of the valve, make certain that bench, tools, and all valve parts are thoroughly clean and free from dust and foreign matter. If necessary thoroughly rewash the parts.

Coat all valve component parts and body bores with good grade of hydraulic oil.

2. ASSEMBLE AND INSTALL SPOOLS AND CHECKS (See Illustration 2-7) To assemble spring centered spool, clamp the spool in a soft-jawed vise, eye end up. Be sure to get correct end as the spool is not symmetrical. Drop in the check poppet; if new parts are not used, be sure that poppets are installed in their respective bores. Place spring into. Install new “O” Ring on spool eye and screw into spool and tighten using loctite thread lock and 30 to 40 inch pounds of torque. Allow loctite to cure before applying hydraulic pressure.

Reverse the spool in the vise and assemble check in this end in the same way. Then place spring spacers and spring on spool. Compress the spring and install new snap ring per paragraphs 2b and 2c and Illustrations 2-9 and 2-10 under Tools.

Place “O” Ring retainer and new “O” Ring on spool assembly. Place new “O” Ring (8) in valve body.

Install spool into body being careful not to cut the “O” Ring. With the spool fully inserted in the valve body bore, install the spool cap.

© Crown 1978 PF-3374-4

M2.3 - 11 - 004

Do not attempt to adjust relief valve to its proper setting at this point. See instructions on Relief Valve Adjustment.

4. INSTALL BODY PLUGS AND “O” RINGS. With spools, check valves and relief valve installed in the body, place new “O” Rings on all body plugs and install in valve body.

Testing After overhaul, the control valve should be tested.

If a test stand is not available, the valve should be installed on the equipment for test.

RELIEF VALVE ADJUSTMENTS On Control Valve (Crown No. 78716) using the relief valve (82981), the following adjusting procedure should be used (See Illustration 2-11): Remove cover (P), washers (J) and (L), and fitting (K).

Loosen nuts (D) and (N). Unscrew setscrew (F) to relieve spring tension and close gap (R). With pressure gage in pump, valve line, adjust setscrew (C) to desired low pressure setting and tighten nut (D) to lock.

Pressure differential above low setting is determined by factory preset gap (R). Adjust setscrew (F), observing pressure rise on gage. At the point where the pressure stops rising, tighten nut (N). Gap (R) is then fully open and springs (A) and (E) are in balance. Reassemble washers (J) and (L), fitting (K), and cover (P).

PRESSURE LIMITATIONS Minimum low pressure setting Maximum differential pressure Maximum high pressure setting

400 PSI 1500 PSI 3000 PSI

OPERATION Valve is normally set at higher pressure. When pressure in pilot line is in excess of 200 PSI, piston (G) followed by piston (B) is moved to close gap (R). This relaxes spring (A) and the low pressure setting is in effect.

Printed in U.S.A.

M2.3 - 11 - 004

MAINTENANCE On control valve (Crown No. 78716) using the relief valve (85523), the following adjusting procedure should be used (See Illustration 2-12): 1. With no pressure in the pilot port, loosen lock nut “A”.

2. Adjust screw “B” to obtain high setting (lift).

3. Remove acorn nut “E”.

4. Loosen jam nut “D”.

5. With pressure in the pilot port, adjust screw “C” to obtain the desired low setting (tilt).

High pressure setting should be approximately 2300 PSI and should be checked for lifting the rated capacity of the truck but not more than 10% over capacity.

Low pressure setting should be approximately 950 PSI and should be checked tilting a rated capacity load.

On control valve (Crown No’s. 75439, 75810, 75811, 76292 & 77595) using the original relief valve, the following adjusting procedure should be used (See Illustration 2-7): ILLUSTRATION 2-11

RELIEF VALVE ADJUSTMENT. 1. Provide a means for connecting a 3000 PSI gage at the inlet side of the valve. A tee at the inlet port may be used.

2. Remove acorn nut from relief valve. Loosen jam nut and hold while backing off adjusting screw until no tension is felt on relief valve.

3. With pump running at maximum speed, operate one spool to a power position. Turn adjusting screw clockwise until correct pressure setting is obtained. Correct pressure setting should be obtained from the schematic located at the end of this manual.

4. After correct pressure setting has been obtained, hold screw and tighten jam nut. Install and tighten acorn nut.

ILLUSTRATION 2-12

© Crown 1978 PF-3374-5

M2.3 - 11 - 005

Printed in U.S.A.

M2.3 - 11 - 005

MAINTENANCE Lift Relief Valve Setting Adjust the relief valve to lift and release within the capacity limits and load center rating shown in Chart 2-13

CHART 2-13 The load center is the horizontal distance along the forks from the load backrest to the center of gravity of the load.

All trucks must be able to lift this load above free lift height ** Insert applicable truck series ‡ TL trucks – check the load within the last 12″ of lift EXTERNAL LEAKAGE TEST. Special Features †

If the repaired valve has two or more spools, operate the spool farthest from the relief valve to a power position and hold against the relief valve. Check all external port connections and seals for possible leakage.

SPOOL OPERATION.

1. EXTERNAL HIGH PRESSURE CARRY-OVER. (See Illustration 2-14) This valve is available with a special high-pressure carry-over port which provides an outlet for full flow pressure to an additional valve connected in series.

Operate each spool on the valve to its power position.

Spools equipped with spring return should move from the power position to neutral without any hesitancy.

CHECK VALVE LEAKAGE TEST. Operate each spool in its power position under load, until about half the stroke of the cylinder is reached. Return the spool to neutral position and again apply load to cylinder. There should be no cylinder drop when the load is again applied. With the cylinder port still under load, stop pump flow to the control valve by either turning off the test stand pump motor or the vehicle engine, and carefully move the valve spool from the neutral to the power position. In the power position, the load should remain stationary. If the load does not remain stationary, the check valve should be repaired per instructions.

© Crown 1978 PF-3374-6

M2.3 - 11 - 006

ILLUSTRATION 2-14

Printed in U.S.A.

M2.3 - 11 - 006

MAINTENANCE

NOTE Outlet ports of all valves must be connected to tank.

2. CLOSED CENTER. (See Illustration 2-14) This control valve is available with closed center circuit which eliminates the bypass side of the circuit. The construction is similar to the High Pressure Carry-Over. On this model a solid adaptor plug is used in place of the High-Pressure Side Carry-Over.

If switch is suspected of being faulty, a continuity check can be made between terminals 1 and 3, and 2 and 4.

Connect a test lamp, in series, to each set of terminals.

Lamp should light when moving switch plunger 0.040 0.050 inch in either direction from the mid position.

Maximum plunger travel into switch is 0.500 inch.

Replace switch if there is evidence of malfunction.

3. ELECTRIC SWITCH. (See Illustration 2-15) A special electric switch is available for installation on the control valve. The switch is a single pole, double throw, double break type. The switch plunger contacts the end of the valve spool and electrical contact is made by pushing or pulling the spool to a power position.

Refer to parts list for part numbers.

INSTALL AND ADJUST SWITCH. To install the electric switch on a standard control valve, proceed as follows: Unscrew and remove the standard spring centered spool cap and replace with special switch cap.

Loosen switch clamping screw and place switch over machined end of special switch cap, then observing switch contact plunger through clear plastic cover, position switch until moving contact is mid-way between stationary contacts. Tighten clamping screws securely to insure holding at this adjustment.

Test switch action by operating spool in each direction and visually observing plunger contacting the stationary contacts. Readjust if necessary.

ILLUSTRATION 2-16 4. PILOT OPERATED CHECK VALVE. (See Illustration 2-16) To remove, unscrew caps at both ends of body.

Take out springs, balls, and ball guides. Using a 1/4 wood dowel, push shuttle (8) and seats (6) out of the body. Identify parts so they are returned to the same spot when reused.

Inspect parts for wear and replace all bad parts.

Discard all “O” Rings and replace with new ones.

When rebuilding be sure the shuttle is in the body as shown with the small end of the shuttle towards the spring end of the main spools.

A special control spool is used with this lock check.

There are no checks in the spool and flats are provided to bleed off pressure in neutral so shuttle will not function in neutral.

ILLUSTRATION 2-15

© Crown 1978 PF-3374-7

M2.3 - 11 - 007

Printed in U.S.A.

M2.3 - 11 - 007

MAINTENANCE

Trouble Shooting

CHART 2-17 © Crown 1978 PF-3374-8

M2.3 - 11 - 008

Printed in U.S.A.

M2.3 - 11 - 008

MAINTENANCE CONTROL VALVE - CESSNA

ILLUSTRATION 2-18 Disassembly 1. Plug all ports and clean outside of valve thoroughly.

2. Remove detent cap (#32). When detent cap is being removed, care should be taken not to lose spring (#29) and balls (#30).

3. Remove caps (#1). Do not remove screws (#2) and (#31) from spool assemblies unless spring (#26) needs to be replaced. The spring need not be replaced unless it is broken.

4. Remove spools (#4), (#22) and (#23) from valve body.

© Crown 1978 PF-3375-1

M2.3 - 11 - 011

NOTE Spools and bodies are matched sets. Be sure each spool is identified with the correct body bore.

5. Remove bushings (#24) and “O” Rings (#15) from spools.

6. Remove orifice plates (#9) and (#14).

CAUTION

Check position and location of orifice plates when removed to assure proper assembly.

Printed in U.S.A.

M2.3 - 11 - 011

MAINTENANCE 7. Remove relief valve plug (#16), shim (#17), spring (#19), and poppet (#20) from body.

NOTE Do not remove poppet seat. Seat has been set to predetermined depth and locked in place.

8. Remove lift check plug (#10), spring (#12), and plunger (#13) from body.

9. Remove pressure beyond plug (#5) from body.

10. Remove “O” Rings (#15) from body bores.

11. Remove all “O” Rings and back-up washers from all plugs.

Inspection 1. Remove all nicks and burrs from parts and inspect for excessive wear.

2. Inspect spool spring, relief valve spring and lift check spring for breakage.

3. Inspect relief valve poppet for breakage or wear.

4. Inspection of “O” Rings, and back-up washers is not necessary. It is recommended that they be replaced as new parts when valve is serviced.

Service of Relief Valve The pin type relief valve is serviced when disassembly of the valve is accomplished. If a higher or lower system pressure is required, shims (#17) may be added or taken out as needed, noting that adding shims increases pressure; removing shims decreases pressure. (See Illustration 2-19) Electrical Switch Adjustment To adjust the switch, shims must be added between the switch and the switch mounting plate. (See Illustration 2-19) Shim switch so that the spool travels .020″/.060″ [.51mm/1.52mm] between switch contacts (clicks). Spool travel in either direction from neutral must not be less than .010″ [.25mm] nor greater than .050″ [1.27mm] when switch contacts (clicks).

Reassembly 1. Thoroughly clean and dry all parts. Metal parts should be lightly oiled prior to assembly.

NOTE All “O” Rings and back-up washers should be replaced as new parts.

2. Position new “O” Rings (#15) in proper grooves in spool bores.

3. Install new back-up washers and “O” Rings on plugs.

RELIEF VALVE SHIMS (#17)

4. Install relief valve components (#20), (#19), (#17), and (#16).

5. Install lift check components (#13), (#12), and (#10).

6. Install pressure beyond plug into body.

7. If screws (#2) and (#31) have been removed to replace spring (#26), they should be installed with loctite and torqued 5 to 8 ft. lbs.

8. Slide bushing (#24) over spool, slide new “O” Ring (#15) over spool and position next to sleeve.

9. Dip spools in oil and install spool and spring assemblies (#4) and (#22) in proper location.

SWITCH SHIMS

10. Install balls (#30) and spring (#29) by placing index finger over bottom hole in screw (#31). Place one ball, then the spring and other ball into the hole. With the cap (#32) in other hand, assemble the two parts with bottom hole entering the cap first and at the same time sliding index finger away from the hole. Press other ball down with thumb, and slide cap on and back into detent position.

11. Install detent spool assembly into proper location.

12. Install caps (#32) and (#1) to secure spool assemblies.

ILLUSTRATION 2-19

© Crown 1978 PF-3375-2

M2.3 - 11 - 012

13. Install orifice plates.

Printed in U.S.A.

M2.3 - 11 - 012

MAINTENANCE

Trouble Shooting Guide

Crown 1978 PF-3375-3

M2.3 - 11 - 013

Printed in U.S.A.

M2.3 - 11 - 013

C

DRIVE UNIT

Fill Plug Oil Level Check Drain Plug

Drain Plug Figure 3393

Your Crown lift truck has a drive unit centrally located in the power unit. The drive unit is a double reduction gearbox providing strength and efficient operation. The unit is totally enclosed and oil filled to provide maximum lubrication to both bearings and gears.

The drive unit has a capacity of approximately 1000 ml (3.25 pints) of 90W gear lube, 063002-003. Remove filler plug located in the side cover, refer to Figure 3393. Add gear oil until present at oil level check plug hole in the lower housing, just above the idler shaft. Remove both drain plugs to completely drain drive unit.

See Torque Value Chart at the end of this section.

Drive Tire Replacement When replacing the drive tire, make sure the composition and size are such that maneuverability and capacity are maintained. The drive tire is a press-on type. To replace, press old tire off and new tire on. The following procedure should be followed to remove the drive tire assembly from the drive unit. Elevate power unit and block securely. Remove the roll pin locking the castle nut to the end of the axle.

Use a 1 1/2 in. wrench and remove the castle nut from axle.

Pull axle from drive unit while stabilizing the drive tire. Refer to Figure 3393.

Be sure the battery is disconnected before performing any maintenance operations.

Drive Motor Removal NOTE Removal of motor for replacement of brushes is not necessary.

Turn the drive unit to the right or left as far as possible. Open power unit doors and disconnect battery. For trucks not equipped with an electric brake assembly, remove the three screws securing the brake drum to the split bushing. Release the brake and remove the drum. Remove the retaining ring, split bushing and woodruff key from the drive motor shaft. For trucks built October 1, 1986 and after (equipped with an electric brake assembly) refer to section M5.0 Brake Maintenance for brake removal guidelines. Disconnect all electrical connections from terminals on drive motor. Label electrical cables if necessary to eliminate problems when replacing motor. Remove the two motor mounting screws located above and slightly off to the side of the motor shaft, refer to Figure 3393. Turn the drive unit to the left as far as possible. Support the drive motor and remove the two screws from the bottom of motor. Pull motor straight out of casting to prevent damage to motor shaft seal.

12592

M3.0–07.2–015 07 Rev. 12/05

Crown 1985 PF7188-1 Rev. 12/05

C

DRIVE UNIT

Drive Unit Removal NOTE In most cases repair to the drive unit can be made with the drive unit in the power unit. However, should it be necessary to remove the complete drive unit from truck, the following procedure should be followed.

Elevate and block the power unit; the drive tire must be off floor.

Remove steering mechanism, control handle, etc. from top of drive unit.

SP ONLY. Disconnect brake line at base of mainframe.

Drain brake fluid into container. Unclamp and unthread brake line from power unit. Trucks built October 1, 1986 and after (equipped with an electric brake assembly) hydraulic brake lines do not exist.

Disconnect motor cables from contactor panel; disconnect brake switch leads.

Figure 0357S-02

Attach a hoist to support plate at top of drive unit, near the thrust plate. Use caution not to damage brake linkage, if so equipped in the process.

Loosen and remove the (3) screws connecting the thrust plate to the power unit and carefully raise the drive unit until it is clear of the power unit.

Remove the drive wheel axle (item 9, Figure 0357S-02).

Remove the roll pin (item 10) locking the castle nut (item 13) to the end of the axle. Use a 1 1 /2 in. wrench and remove castle nut from axle. Pull axle from drive unit housing while stabilizing the drive tire.

NOTE

Unfasten the four screws (item 32 & 29) and remove the cover (item 33) and the gasket (item 34).

The drive unit should be taken to a clean work area if further disassembly is necessary. Make sure the vented fill plug is to the top side of unit if it is necessary to lay the drive unit down for transporting, etc.

Remove the retaining ring (item 27), access it through the slots in the face of the second reduction gear (item 28). Large retaining ring pliers with a locking ratchet such as a Waldes Truarc No. S-6700, Crown no. 092668, should be used (see Figure 3394).

Drive Unit Disassembly The following disassembly and assembly procedure is a complete tear down and rebuild operation. Once the problem has been diagnosed the repair procedure can be used that covers the necessary repair.

LOWER HOUSING Drain gear oil.

In order to separate the drive unit top from the drive unit bottom remove the six screws (item 17, Figure 0060S-01) securing the two drive unit sections together.

Crown 1985 PF7188-2 Rev. 12/05

Figure 3394

M3.0–07.2–016 07 Rev. 12/05

C

DRIVE UNIT Pull the gear (item 28) and the bearing (item 26) assembly from the housing. If the bearing needs replacement, remove the retaining ring (item 7) and press off the bearing.

Remove the inside oil seal (item 24).

Remove the alignment dowel pin (item 3) located directly above the idler shaft (item 18) and then remove the idler shaft.

Pick out the loose spacers (item 23) and the gear assembly (item 20, 21 & 22) from the top cavity in the lower housing.

Move to the other side of the housing and remove the bearing (item 6) and the bearing adapter (item 5) after unseating and removing the retaining ring (item 8). If this bearing needs replacement, remove the retaining ring (item 7) and press off the bearing.

Remove the roller assemblies (items 11 & 15) by removing the set screw (item 14) located in the housing and removing shaft (16 & 38).

UPPER HOUSING Refer to Figure 0060S-01. Remove the support assembly (item 1). Remove the spacers (item 2). Note the number and position for reference at assembly. Lift off the thrust plate (item 3) which contains a felt seal (item 5) and a bearing cup (item 6).

Remove bearing cone (item 8) and felt seal (item 7) from top of upper housing (item 16).

After the motor (item 11) has been removed, the oil seal (item 32) can be removed from either side of its bore.

Remove cover (item 26) and gasket (item 25) from the side of the housing.

Remove cotter pin (item 24) and unscrew the castle nut (item 23) about half way off the end of the pinion shaft (item 15).

While supporting gear (item 20), gently tap on the end of pinion shaft via the castle nut. This will unseat the gear and bearings (items 14 & 19), as well as push out the expansion plug (item 13).

Once the bearings are free, slide the pinion shaft to the left until the gear (item 20) is clear and can be removed along with the two keys (item 21).

Continue to slide the pinion shaft and catch the bearing’s (item 19) right inner race [cone] along with the inner race spacer.

When the pinion is moved far enough, remove the left inner cone and then completely remove the pinion shaft.

Remove the bearing outer races and the bearing retaining ring from housing.

NOTE The #10-24 tapped hole located directly below the retaining ring slot is to be used to help unseat the retaining ring. Use a #10-24 x 1 in. screw (060014-010).

Figure 0060S-01

M3.0–07.2–017 07 Rev. 12/05

After inspecting the housings and before reassembly, thoroughly clean in solvent and blow dry.

Crown 1985 PF7188-3 Rev. 12/05

C

DRIVE UNIT

Bearing (Item 14)

Pinion (Item 15)

Right Outer Gear Left Outer Race (Cup) (Item 20) Race (Cup) Retaining Left Inner Right Inner Washer Ring Race (Cone) Race (Cone) (Item 22) Spacer

Cover (Item 26)

Expansion Plug (Item 13)

Cotter Pin (Item 24)

Left Bore

Spacer Retaining Ring Unseating Hole

Gasket (Item 25) Middle Bore

Key (Item 21)

Castle Nut (Item 23) Figure 3395

Drive Unit Assembly NOTE If the upper or lower housings were replaced, before proceeding with assembly, check the housings for burrs or casting slag. Also, the area where the lower part of the motor mounting plate rests in the upper drive unit housing should be checked, and ground if necessary, to assure a proper fit.

After inspection and grinding, thoroughly clean the housings in solvent and blow dry.

UPPER HOUSING With the upper housing (item 16) in the same relative position as the housing in Figure 0060S-01, install the lower grommet (item 9) into the neck of the housing.

Preassemble the key (item 31) and the gear (item 30) onto the motor (item 11). After the components are in position, insert the retaining ring (item 29) into its groove on the end of the motor shaft.

Grease the motor shaft and its bore and install the oil seal (item 32). Refer to Drive Motor Shaft Seal Replacement.

With the use of an arbor press, force the left outer cup of the bearing (item 19) into the middle pinion bore (See Figure 0060S-01). This bearing includes two inner bearing cones, two outer bearing cups, a spacer and a retaining ring spacer.

After the left outer race has been pressed slightly past the groove, install the retaining ring spacer.

Slide the pinion shaft (item 15) through the left bore. Install the left inner race and spacer onto the right side of the pinion shaft prior to the shaft entering the middle bore.

Move the shaft through the middle bore to a position where the right inner race, right outer race and the gear (item 20) can be installed.

Once installed, force the pinion completely in and insert the two keys (item 21) into the gear.

Apply a light film of multi-purpose grease (063002-025) to the face of the motor and place the gasket (item 10) onto the greased mounting face. Insert the complete motor assembly into the housing and secure the fasteners.

Slide the bearing (item 14) and the expansion plug (item 13) in place on the left bore before installing the washer (item 22) and the castle nut (item 23) on the opposite end of the pinion shaft (item 15).

NOTE

Tighten the castle nut (item 23) to 203 - 271 Nm (150 to 200 ft/lbs), then insert the cotter pin (item 24). Bolt the cover (item 26) and the gasket (item 25) to the right side of the upper housing and insert the filler plug (item 28) into the cover.

Two bolts fasten from the inside of the housing and two bolts fasten from the outside. When tightening these bolts, follow a diagonal tightening procedure to insure proper motor seating.

Crown 1985 PF7188-4 Rev. 12/05

M3.0–07.2–018 07 Rev. 12/05

C

DRIVE UNIT Attach the brake assembly to the side of the upper drive unit housing. For trucks not equipped with an electric brake assembly, torque the two screws securing the brake assembly to the drive unit to 17.5 - 23 Nm (13 - 17 ft/lbs). For trucks built October 1, 1986 and after (equipped with an electric brake assembly) refer to section M5.0 Brake Maintenance for brake installation guidelines.

Apply a thin film of multi-purpose grease to the upper bearing neck on the housing and install the inner race (item 8). Once in position, thoroughly grease the rollers and roller cage of the bearing.

Spacer

Figure 3396 Figure 0357S-02

Insert the felt seal (item 7) into the groove which encircles the inner race. The felt seal ends must meet squarely to assure a good seal. The felt can be stretched or compressed to accomplish this.

Insert the retaining ring (item 27) into its mounting slot in the bore by means of snap ring pliers (see Figure 3394) inserted through the slots in the gear face.

Press the outer race (item 6) into the thrust plate (item 3) and install the grease zerk into the side of the plate.

Preassemble the gear (item 21) with its bearing (item 22) and the retaining rings (item 20).

Assemble the thrust plate assembly on top of the upper bearing neck and install the felt seal (item 5) in between the bearing neck and the thrust plate bore.

Place the gear assembly between the two spacers (item 23) and place them into their relative mounting position in the housing.

Install spacers (item 2) to fill the gap between the top of the thrust plate and the bottom of the support assembly. Refer to Figure 0060S-01.

When the gear assembly is properly positioned, insert the idler shaft (item 18) which has been preassembled with Orings (item 17 & 19). Lock the shaft in place with one of the dowel pins (item 3).

Bolt support assembly (item 1) to the upper drive unit housing.

LOWER HOUSING Position the lower housing (item 25) in the same manner as the housing is shown in Figure 0357S-02.

Lay the retaining ring (item 27) around the inside gear neck and then press the bearing (item 26) onto the neck to a position where the retaining ring (item 7) can be installed.

After greasing the outside diameter of the bearing (item 26), press the entire gear assembly into the housing.

M3.0–07.2–019 07 Rev. 12/05

Left Side

Right Side Figure 3397 Crown 1985 PF7188-5 Rev. 12/05

C Apply a film of grease to the mounting surface of the cover (item 33) and place the gasket (item 34) onto the greased cover surface. Also grease the neck of the gear (item 28) in the area where the oil seal will ride. Install the cover onto the housing and insert and tighten its fasteners evenly.

Insert bearing adaptor (item 5) into the bearing (item 6). Coat the lower right side drive axle bore with grease, press bearing assembly in position and install retaining ring (item 8).

Install oil seals. Refer to Seal Replacement in this section.

Place slinger (item 36) in position over inner axle seal.

Position the wheel assembly in the housing. Install outer slinger (item 36) onto the axle and slide the axle (item 9) through the left side bore. Align the axle splines and fully seat the axle.

Before installing axle, coat axle with anti-seize compound (065005-003). Ensure that the washers (item 40) are installed opposing each other. Torque the axle nut (item 13) to 68 Nm (50 ft/lbs). Loosen, then retorque to 108 Nm (80 ft/lbs).

FINAL ASSEMBLY After the upper and lower drive unit halves have been completely assembled, insert the dowel pins (items 37 [Qty. 2] & item 3 [Qty. 1]) into the lower housing.

Apply a coat of gasket sealer (065005-002) to the mounting surface, at the point where the housings join.

DRIVE UNIT SEAL REPLACEMENT AXLE INNER SEAL Drain gear lube from drive unit. Remove drive tire assembly per instructions located in the beginning of this section .

Remove the old seal. Be sure not to nick or scratch the sealing surfaces of housing or gear hub. Thoroughly REMOVE the old gasket sealing material from the bore.

Apply a thin coat of gasket sealer, 065005-001, to the housing bore. The seal lip should be lubricated with the fluid being retained or compatible grease.

NOTE Care must be taken not to get any gasket sealer on either the seal lip or the seal surface of the gear hub.

Position the new seal in proper alignment and gently tap with plastic mallet to start the seal into the housing bore not in excess of 1.5 mm (.06 in.).

Carefully press the new seal into position. The seal’s outer shell should not be more than 0.8 mm (.030 in.) beyond the end of the gear hub. For more information refer to Technical Service Bulletin No. 152 and 091009 tool assembly.

Replace drive tire and axle. Fill unit with proper amount and type of gear lube.

OUTER AXLE SEAL

Set the gasket (item 2) and the shims (item 1) on the mounting surface of the lower housing and then couple the two halves together. If the housings do not seat completely, rotate the drive wheel. This will help mate the gears.

Refer to steps 1 thru 4 of Axle Inner Seal replacement procedure.

Insert the six fasteners (item 17) and tighten the bolts to a torque reading of between 34 - 40 Nm (25 - 30 ft/lbs).

Carefully press the new seal into position. The seals outer shell should not be more than 2.8 mm (.110 in.) beyond the end of the gear hub. For more information refer to Technical Service Bulletin No. 152.

Insert and tighten drain plugs (item 4) and fill with gear lube.

Test the drive unit motor assembly for tight bearings by rotating the motor shaft with a torque wrench. The rotating torque should be 0.9 - 1.8 Nm (8 to 16 in/lb).

Replace drive tire and axle. Fill unit with proper amount and type of gear lube.

Reinstall the drive unit into the power unit by reversing the six steps described in Drive Unit Removal in the front of this section. The three bolts (item 4) which fasten the thrust plate (item 3) to the power unit bracket are to be tightened to a torque reading of 108 - 122 Nm (80 - 90 ft/lbs).

Crown 1985 PF7188-6 Rev. 12/05

M3.0–07.2–020 07 Rev. 12/05

C

DRIVE UNIT DRIVE MOTOR SHAFT SEAL

THRUST ROLLER REPLACEMENT

Remove brake drum, split bushing and woodruff key from drive motor shaft.

Remove set screw and remove roller shaft. Remove roller, flatwasher(s) and felt seal from lower drive housing. The roller bearings are part of the roller assembly. Do not attempt to remove bearings from the roller bore. The flatwasher and felt seal can be reused. Refer to illustration for proper position and/or location of Thrust Roller parts.

Carefully remove old seal from drive unit housing. Do not nick or scratch the sealing surfaces of the housing or motor shaft.

Thoroughly remove the old gasket sealing material from the housing bore. Inspect the motor shaft sealing surface area.

Should a groove, nick or any slight imperfection be present the new seal can be pressed slightly beyond the original position in the housing bore. An additional depth of up to 3.2 mm (.125 in.) is allowable, any seal installation with a greater depth may not provide adequate seal surface.

Apply a thin coat of gasket sealer. 065005-001, to the housing bore. The seal lip should be lubricated with the fluid being retained.

NOTE Drive units with steel thrust roller throughout cannot use poly core thrust roller.

The thrust rollers must be lubricated and maintained properly to achieve proper truck operation and obtain satisfactory service life from component parts. All thrust rollers must turn freely and smoothly during normal truck operation.

NOTE Care must be taken not to get any gasket sealer on either the seal lip or the sealing surface of the motor shaft.

Protect the seal lip from sharp edges or burrs on motor shaft.

Position seal installation sleeve on motor shaft. Use 094614 sleeve when installing 073433 seal & 094615 sleeve when installing 087795 seal. Align the seal properly and gently press into housing. Remove seal installation sleeve from motor shaft. Install woodruff key, split bushing and brake drum on drive motor shaft. For trucks not equipped with an electric brake assembly, torque the three screws that attach the brake drum and tapered bushing to the motor shaft to 11 - 13.5 Nm (8 - 10 ft/lbs). For trucks built October 1, 1986 and after (equipped with an electric brake assembly) refer to section M5.0 Brake Maintenance for brake installation guidelines.

M3.0–07.2–021 07 Rev. 12/05

Crown 1985 PF7188-7 Rev. 12/05

C

DRIVE UNIT Torque Value Chart Upper to Lower Housing Assembly Torque Values: 34 - 40 Nm (25 - 30 ft/lbs) Item 17 Brake Attachment to Drive Unit Torque Values: 17.5 - 23 Nm (13 - 17 ft/lbs) Assembling Brake Drum to Drive Motor Shaft Torque Values: 11 - 13.5 Nm (8 - 10 ft/lbs) Motor Shaft Rotating Torque Values: 0.9 - 1.8 Nm (8-16 in/lbs) Thrust Plate to Power Unit Bracket Torque Values: 108 - 122 Nm (80 - 90 ft/lbs) Item 4

Figure 0060S-01

Castle Nut on Pinion Shaft in Upper Housing Torque Values: 203 - 271 Nm (150 - 200 ft/lbs) Item 23 Castle Axle Nut Torque Values: 68 Nm (50 ft/lbs) Then Retorque to 108 Nm (80 ft/lbs) Item 13

Figure 0357S-02

Crown 1985 PF7188-8 Rev. 12/05

M3.0–07.2–022 07 Rev. 12/05

MAINTENANCE

ILLUSTRATION 3-4 DRIVE UNIT

UPPER HOUSING ASSEMBLY

Your Crown rider lift truck has an independent drive unit located in the center of the power unit. The drive unit is a double reduction gearbox incorporating spur gears for strength and efficient operation. The unit is totally enclosed and oil-filled to give maximum lubrication to both bearings and gears. The drive motor is fitted with a hydraulically released, spring applied, deadman type braking system.

(Refer to Illustration 3-4)

© Crown 1978 PF-3467-1

M3.0 - 12 - 001

NOTE Before proceeding with assembly, the housings should be checked for burrs or casting slag. Also, the area where the lower part of the motor mounting plate rest in the upper drive unit housing should be checked, and ground if necessary, to assure a proper fit. After inspection and grinding, thoroughly clean the housings in solvent and blow dry.

Printed in U.S.A.

M3.0 - 12 - 001

MAINTENANCE

ILLUSTRATION 3-5 With the upper housing (item 62) in the same relative position as the housing in Illustration 3-4, install the lower grommet (item 23) into the neck of the housing.

Preassemble the key (item 82) and the gear (item 83) onto the motor (item 81). After the components are in position, insert the retaining ring (item 84) into its groove on the end of the motor shaft. Apply a light film of multi-purpose grease (Crown No. 63002-7) to the face of the motor and stick the gasket (item 47) onto the greased mounting face. Insert the complete motor assembly into the housing and secure the fasteners.

(Note: Two bolts fasten from the inside of the housing – two bolts fasten from the outside). Grease the motor shaft and its bore and install the oil seal (item 64).

With the use of an arbor press, force the left outer race of bearing (item 74) into the middle pinion bore (see Illustration 3-5). The bearing (item 74) includes two inner bearing races [cones], two outer bearing races [cups], a spacer and a retaining ring spacer.

After the outer race has been pressed slightly past the groove, install the retaining ring spacer. Next, slide the pinion (item 79) through the left bore and then install the inner race and the spacer onto the end of the pinion shaft prior to the shaft entering the middle bore. Move the pinion shaft through the middle bore to a position where the right inner race, right outer race and the gear (item 73) can be installed. Once installed, force the pinion completely in and insert the two keys (item 72) into the gear. Slide the bearing (item 78) and the expansion plug (item 77) in place on the left bore before installing the washer (item 71) and the castle nut (item 70) on the end of the pinion shaft, © Crown 1978 PF-3467-2

M3.0 - 12 - 002

ILLUSTRATION 3-6 Printed in U.S.A.

M3.0 - 12 - 002

MAINTENANCE

ILLUSTRATION 3-7 through the right bore. Tighten the nut and insert and clinch the cotter pin (item 67). Bolt the cover (item 68) and the gasket (item 69) to the right side of the housing and insert the pipe plug (item 63) into the cover.

The next parts to be installed are the brake assembly components. Apply Loctite (Crown No. 61004-4) to the two brake plate screws and secure the brake plate assembly (item 56). Install the brake brackets (items 16, 18 & 45) to the housing and assemble the brake components as shown in Illustration 3-6. Refer to the “Brake” section in this manual for additional brake assembly and adjustment procedures.

Apply a thin film of multi-purpose grease to the upper bearing neck on the housing to aid in the installation of the inner race (item 36). Once in position, thoroughly grease the rollers and roller cage of the bearing. Insert the felt seal (item 35) into the seal groove which encircles the inner race. The felt seal ends must meet squarely, the felt can be stretched or compressed to accomplish this. Press the outer race (item 34) into the thrust plate (item 32) and fasten the grease zerk into the side of the plate. Position and install the upper felt seal (item 33) in its groove on top of the thrust plate — again make sure the ends of the felt seal meet evenly. Preassemble the upper grommet (item 23) and the side grommets (item 30) into the support assembly (item 29) and bolt the assembly to the upper drive unit housing.

© Crown 1978 PF-3467-3

M3.0 - 12 - 003

LOWER HOUSING (Refer to Illustration 3-7) NOTE Before proceeding with assembly, the housing should be checked for burrs or casting slag.

After inspection (and grinding) the housing should be thoroughly cleaned in solvent and blown dry.

Position the lower housing (item 25) in the same manner as the housing is shown in Illustration 3-7. Apply a coat of gasket sealer (Crown No. 65005-1) to the bore in the cover (item 33) and the inside area of lower left side drive axle bore and then press in the appropriate seals (items 31 & 24). After seal (item 24) is seated, grease the remainder of the bore with multipurpose grease (Crown No. 63002-7) as well as the neck of the gear (item 28).

Lay the “bore” retaining ring (item 27) around the gear neck and then press the bearing (item 26) onto the neck to a position where the shaft retaining ring (item 7) can be installed. Press the entire gear assembly into the housing and then insert the retaining ring (item 27) into its mounting slot in the bore by means of a snap ring tool inserted through the slots in the gear face.

Printed in U.S.A.

M3.0 - 12 - 003

MAINTENANCE Move to the gear (item 21) and install the retaining ring (item 20) into the groove in the gear bore. Press the bearing (item 22) into the gear and install the other retaining ring (item 20). Place the gear assembly between the two spacers (item 23) and insert them into their relative mounting position in the housing. When properly positioned, insert the shaft (item 18) which has been preassembled with “O” rings (item 17 & 19) and lock it in place with the dowel pin (item 3).

Apply a film of grease to the mounting surface of the cover (item 33) and stick the gasket (item 34) onto the greased cover surface. Also grease the neck of the gear (item 28) in the area where the oil seal will ride. Install the cover onto the housing and insert and tighten its fasteners.

Press the bearing adaptor (item 5) into the bearing (item 6) and install the retaining ring. After coating the lower right side drive axle bore, press the bearing assembly in position and install retaining ring (item 8). Install the grease zerks into the hub (item 36) and the end of the axle (item 9). Slide the axle through the right side bore and the wheel assembly. When the axle splines are

© Crown 1978 PF-3467-4

M3.0 - 12 - 004

aligned and the axle is fully seated, insert the retaining ring (item 10). Assemble the thrust rollers (item 11) and their associated mounting components (items 12, 13, 15, 38 & 39) on the roller shafts (item 16) and when properly positioned, secure with set screws (item 14).

FINAL ASSEMBLY After the upper drive unit and the lower drive unit have been completely assembled, insert the dowel pins (item 37) into the lower housing. Apply a coat of gasket sealer (Crown No. 65005-1) to the mounting surfaces, at the point where the housing join. Set the gasket (item 2) and the shims (item 1) on the mounting surface of the lower housing. Couple the upper and lower halves together. If the housings do not seat completely, rotate the drive wheel. This will help mate the gears. Once mated, insert the fasteners and tighten the bolts to a torque reading of between 28 and 30 ft./lbs. When the complete drive unit is installed in the truck, the three (3) bolts which fasten the thrust plate to the power unit bracket are to be tightened to a torque reading of between 80 and 90 ft./lbs.

Printed in U.S.A.

M3.0 - 12 - 004

MAINTENANCE ELECTRICAL SYSTEM

Horn and Push-Pull “Push Button” Switches

Inspection and care of the electrical components in an industrial lift truck are a must if long life and efficient, safe operation are to be maintained through the daily use of any powered equipment. The following information is intended to aid in keeping the electrical system in good operating condition.

These switches are located in the top of the control pod next to the twist grip. The center switch, when depressed, sounds the horn. The push-pull switches, located on either side of the horn switch, activates the solenoid operated push-pull control valve which extends or retracts the slip sheet push rack.

CAUTION

Before making checks, either disconnect the battery or jack up the truck and insert blocks so the drive wheel is free of the floor.

TRAVEL CONTROLS The operator can choose variable speeds in either forward or reverse by turning the twist grip, located on the control pod, in the direction desired. By doing this, the operator closes directional and speed switches which regulate the SCR system. The SCR is connected between the battery and the drive motor, where it is switched on and off, providing pulses to the motor. Motor speed is determined by the average of the ON-OFF times seen by the motor. Low speed is obtained with the potentiometer providing maximum ohms to the oscillator section of the control card. To better understand how the system operates, refer to the “SCR” section in this manual.

SWITCHES All switches should be checked regularly to assure safe and efficient operation.

DEADMAN BRAKE SWITCH The deadman brake switch is located on the slave cylinder bracket which mounts to the upper drive unit housing.

The switch is tripped by means of an actuator fastened to the slave cylinder rod assembly. Adjustment is made so that when pressure is applied to the pedal, the switch will activate, allowing power to the control circuit. When pressure is relieved from the pedal, the brake will apply as the switch cuts off power to the control circuit. To adjust, loosen the top and bottom nuts and move the switch in or out until it actuates when pressure is applied to the pedal.

SCR SPEED CONTROL (POTENTIOMETER) Adjustment With the twist grip in the neutral position, connect an ohmmeter across the two leads that come to the potentiometer (one lead must be disconnected to assure a correct reading). The resistance reading should be 5,000 ohms. Rotate the twist grip until the forward and reverse switchettes close; the resistances must be within 250 ohms of each other. Also check that the resistance is 200 ohms or less as the 1A switchette closes. Be sure potentiometer resistance reading does not jump from 0 to infinity in either direction as the twist grip makes contact with the stops. If these readings cannot be obtained in both directions, loosen potentiometer locking nuts and rotate potentiometer in direction required. Be sure potentiometer terminals do not come into contact with switch plate when control head is assembled.

Replacement To replace the potentiometer, remove the covers and move the upper switch plate to the side. The potentiometer bracket can be removed by removing two screws. (Illustration 4-26) Remove old potentiometer and pinion. Install new potentiometer and pinion and mount

Directional Switches and 1A Switch The forward (F), reverse (R) and 1A switches are located in the control pod. These switches are activated by means of actuators and cams located on the twist grip shaft. Check to make sure the actuators allow enough switch over-travel for positive operation.

Control Valve Switches These switches are located on the bottom of the control valve. The correct positioning of these switches are to be flush against the valve. Less feathering is available when the switch is positioned away from the valve. Refer to the hydraulic section for additional information on switch adjustments.

© Crown 1978 PF-3456

M4.0 - 12 - 001

ILLUSTRATION 4-26 potentiometer mounting bracket with the two screws.

Before securing mounting bracket, connect ohmmeter to the potentiometer leads and adjust to approximately 5,000 ohms. Now mate the pinion with the drive gear and check potentiometer adjustment. If readings are okay, secure mounting bracket; if not, turn the pinion one tooth in either direction and recheck. Be sure potentiometer terminals do not interfere with the upper switch plate.

Printed in U.S.A.

M4.0 - 12 - 001

MAINTENANCE

ILLUSTRATION 4-27

Printed in U.S.A.

M4.0 - 12 - 002

M4.0 - 12 - 002

ELECTRICAL WIRING WIRING COLOR CODES The following information is an explanation of terms and symbols which are being standardized on Crown wiring diagrams.

The leads used are limited to the following colors. The color of the wire is based on the function of the circuit in which it is used. Each wire is assigned a three or four digit number. The first one or two numbers identify the color of the lead. The last two numerals number the lead from one thru ninety-nine.

(See chart below) Exceptions to this can be leads supplied by vendors with components. The color of each function shall be shown on the schematic. Each wire shall be identified by a number on the wiring pictorial.

ABBR.

COLOR

NUMBER

FUNCTION

FUNCTION

BLK BRN RED ORG YEL GRE BLU VIO GRAY WHT R/W

Black Brown Red Orange Yellow Green Blue Violet Gray White Red Stripe/White

0 ** 1 ** 2 ** 3 ** 4 ** 5 ** 6 ** 7 ** 8 ** 9 ** 29 **

G/W

Green Stripe/White

59 **

†Reverse †Potentiometer or 2nd Speed †Positive †Hydraulic Solenoid Valves †Forward †Negative †Bypass or 3rd Speed †Hydraulic Pump Motor †Horn †Miscellaneous †Positive that has gone thru a switch †Negative that has gone thru a switch

‡Traction Inputs/Outputs ‡Analog Inputs ‡Battery Positive ‡Non-Battery Positive ‡Status Inputs/Outputs ‡Battery Negative ‡Isolated Negative ‡Load Position Inputs/Outputs ‡Indicators and Warning Devices ‡Miscellaneous ‡Positive that has gone thru a switch ‡Negative that has gone thru a switch or resistor

** - 01 thru 99 †Trucks Prior to 1988 ‡Trucks 1988 to Present

4233 Crown 1978 PF3452-1 Rev. 11/02

Printed in U.S.A.

06 REV. 11/02

M4.1–12.0–001

M4.1–12.0–001

ELECTRICAL WIRING WIRING HARNESS Shown here is a section of a pictorial wiring diagram showing a wiring harness. The wires shown coming from the wiring harness are all labeled on the diagram in such a way as to be able to tell where the other end of a particular wire is connected. Following is an example taken from this wiring diagram.

There are two wires coming from the harness which lead to HNS (Horn Switch) terminal 1 and terminal 2, labeled 2904-TB1-1 and 801-TB1-8 respectively. 2904-TB1-1 is a red stripe wire marked 2904 (see “Wiring Color Codes”), which goes through the wiring harness to Terminal Board 1 (TB1), terminal 1.

801-TB1-8 is a gray wire marked 801 which goes through the wiring harness to connect to Terminal Board 1, terminal 8.

The wires are labeled similarly at Terminal Board 1. The wire shown coming from terminal 1 of TB1 which leads to the Horn Switch is labeled on the diagram 2904-HNS-1 (Red stripe wire marked 2904 which leads to horn switch, terminal 1).

The wire leading to the horn switch, terminal 2 is labeled 801-HNS-2 on the diagram.

6011SI

POWER CABLES Power cables are designated using one of the following abbreviations, followed by a dash number.

Abbreviation PC # 1 PC # 2 PC # 4 PC # 6 PC#10 PC # 1/0 PC # 2/0 PC # 3/0

Part No. 084571 084570 084569 084568 090963 084572 084573 086749

An example of such a cable is PC # 1/0 - 10. The part number for this cable is 084572-010.

Crown 1978 PF3452-2 Rev. 11/02

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06 REV. 11/02

M4.1–12.0–002

M4.1–12.0–002

ELECTRICAL WIRING SYMBOL NOMENCLATURE Abbreviation F# R# A B C P* S K* 1A ACS AS AXA AXB AXC AXF AXR AXS* BRS* BS CA* CAP* CHS* CLS CS DB* DIS DMS* DRS ECR* EDS EMS* FS FU* GUS HF* HN HNS HSC HSS JC* KYS

Component

Abbreviation

Forward Contactor Reverse Contactor Speed Contactor Speed Contactor Speed Contactor Pump Contactor Power Steering Contactor Relay Contactor SCR Bypass Contactor Accelerator Switch Switch for A Auxiliary Switch A Auxiliary Switch B Auxiliary Switch C Auxiliary Forward Switch Auxiliary Reverse Switch Auxiliary Switch Brake Switch Switch for B Connector Assembly Capacitor Chain Switch Clamp Switch Switch for C Diode Block Directional Switch Safety Switch Door Switch

LGS* LMS* LOS MFS* ORS PC* PLS POT* PRS PTS PUS RAS* RES* RIS RLS ROS RRS RS RTS SAS SB* SES* SLS SQS* SRS SSC SSS STS SV* TB* TD* TDS TES TLS TRS TT TBS TVS V XC*

Emergency Disconnect Switch Emergency Switch Forward Switch Fuse Guidance Switch Hash Filter Horn Horn Switch High Speed Card High Speed Switch Jack (Receptacle) Part of CA Key Switch

Component Light Switch Limit Switch Lower Switch Multi-Function Switch Override Switch Plug Part of CA Pivot Left Switch Potentiometer Pivot Right Switch Pivot Switch Pump Switch Raise Switch Resistor Reach In Switch Rotate Left Switch Reach Out Switch Rotate Right Switch Reverse Switch Rotate Switch Safety Switch Suppressor Block Seat Switch Side Shift Left Switch Sequence Switch Side shift Right Switch Safety Switch Card Side Shift Switch Power Steering Switch Solenoid Valve (Hydraulic) Terminal Board Time Delay Tilt Down Switch Test Switch Traverse Left Switch Traverse Right Switch Hour Meter (Travel Time) Tilt Back Switch Traverse Switch Discharge Meter (Volt Meter) Card Edge Connector

* If more than one, use suffix 1, 2, 3... # If more than one, use suffix A, B, C....Z NOTE The abbreviations listed above are examples of abbreviations found on wiring diagrams. It’s not a complete list of all abbreviations on wiring diagrams in this manual. For a complete list, refer to the glossary located in section M10.

Crown 1978 PF3452-3 Rev. 11/02

Printed in U.S.A.

06 REV. 11/02

M4.1–12.0–003

M4.1–12.0–003

ELECTRICAL WIRING 3804

Maintained Contact Switches Operator Actuated

Momentary Contact Switches Operator Actuated

Normally Open

Normally Open

Normally Closed

Held Open

Center Off

Normally Closed

Double Throw

Held Closed

2 Circuit

Multiple Pole Break Before Make

Center Off Multiple Pole Make Before Break Double Throw Start Acc Ign

Key Switch

Momentary Contact Switches Mechanically Actuated Normally Open

Off Momentary Contact Switches Mechanically Operator Actuated

Normally Open Held Closed

Normally Open

Normally Closed Held Open

Held Closed

Normally Closed

Held Open

Normally Closed Open On Rise

Close On Rise

Double Throw

2 Circuit

Crown 1978 PF3452-4 Rev. 11/02

Printed in U.S.A.

06 REV. 11/02

M4.1–12.0–004

M4.1–12.0–004

ELECTRICAL WIRING 3805

Thermistor PM Motor

T

Rheostat

Mov or Transzorb Suppressor

Wound Motor Armature Motor Field

Current Shunt

Lamp

Zener Diode Diode

SCR

Connection Point Tach Sensor Power Termination Mast Cable

I

Encoder

Common Isolated LED

B

Battery Negative Fuse

Horn

Transformer

SIP Resistor Coil Battery Solenoid Valve or Relay With Suppression

Inductor

Normally Closed

Polarized Capacitor

Normally Open

Non-Polarized Capacitor

Plug PC

LVDT

Connector CA

Resistor

Jack JC Test Point

Potentiometer

Crown 1978 PF3452-5 Rev. 11/02

Printed in U.S.A.

06 REV. 11/02

M4.1–12.0–005

M4.1–12.0–005

MAINTENANCE SCR ELECTRONIC CONTROL The Crown SCR Electronic Control is a solid state electronic speed control which enables the energy from a fixed voltage DC source to be fed to an electric motor smoothly and without the power losses associated with other means of speed control.

0946S

2831P

The operation of the system consists of switching the full battery voltage to the traction motor for very short periods of time. The motor does not respond to the individual voltage pulses but rotates at a speed corresponding to the average voltage which is determined by the number of pulses per second. The vehicle accelerator pedal sets the pulse frequency and hence the average motor voltage any where from zero up to battery voltage, smoothly and with minimal energy losses. The pulses are made possible by a device known as a thyristor or SCR. This is, in fact, nothing more than a solid state switch which is capable of handling high currents.

Let us briefly consider how an SCR works. Illustration 1 shows the SCR. Note that it is a three terminal device. The two main terminals which are called the ANODE and the CATHODE, carry the working current. The third electrode, known as the GATE, is the switching electrode.

Normally the SCR is non-conducting. However, if we apply positive voltage to the anode with respect to the cathode, and then apply a gate signal (also known as a TRIGGER signal) to the gate electrode, the SCR will switch to a conducting state, we have thus closed the switch.

ILLUSTRATION 1

One of the peculiarities of an SCR is that it will continue to carry current, once it is in the ON state even if the GATE signal has been removed. In order to return the SCR to its non-conducting state, it is necessary to interrupt the current flow or to reverse the polarity of the source of supply. One means of switching the SCR off without excessive power losses or risks of battery short circuits is through the use of a resonant charging circuit.

Briefly, a capacitor is charged and the polarity of the charge is reversed and held for the duration of a PULSE. Then by means of an auxiliary SCR, the energy stored in the capacitor is discharged in the form of a reverse current through the SCR. This current nullifies the battery current in the SCR and allows the SCR to return to a non-conducting state. We now have a method of applying a series of rapid PULSES to the motor via the solid state switch - SCR. (Each time the SCR switch closes, battery voltage is applied to the motor. This is called a PULSE.) The SCR acts as a very high speed switch which connects and disconnects the motor directly to the battery for short time periods. During the short time the motor is connected to the battery and because of the small amount of initial current the motor has very little

4277 Crown 1984 PF-5678-1 Rev. 2/94

Printed in U.S.A.

02 REV. 2/94

M4.2 - 06.5 - 001

M4.2 - 06.5 - 001

MAINTENANCE rotation movement. The diagram below, Illustration 2, shows a very simplified representation of the basic circuit.

However, the SCR speed control works by feeding the motor a rapid series of PULSES, and the number of PULSES, per second determines the average voltage at the motor terminals. This is demonstrated in Illustration 3.

When the SCR switch is closed (as shows in Illustration 4) current builds up since we now have a source of voltage to “get things going”. However, when the switch opens and there is no longer a source of external voltage, the inductor tries to keep the current flowing. We have provided a “flyback diode” which allows the current to flow even when there is an open SCR switch. The two Illustrations (4 & 5) therefore show the current paths with the switch closed and immediately after its opening. Thus we see that the direction of the current through the motor does not change, and, what is more important, when the switch opens, although the battery current stops, the motor current continues to flow via the flyback diode.

THE MOTOR CURRENT IS MADE UP OF COMBINATION OF BATTERY CURRENT AND FLYBACK CURRENT.

ILLUSTRATION 2

ILLUSTRATION 3 Let us now take a closer look at the simplified diagram of the SCR circuit. In Illustration 4 you will see a device called the “flyback diode” in the circuit around the motor.

Now, we shall explain the reason behind this arrangement. A mechanical flywheel is a very “contrary” device.

It will resist any attempts to increase its speed of rotation, and after the force causing the rotation has been removed, the flywheel will continue to rotate, resisting efforts to stop it. There is an electrical analog of the flywheel called an INDUCTOR. The inductor also resists, in this case it resists voltage thus causing the current flowing in the inductor to increase. However, being as “contrary” as the flywheel, the inductor will maintain the current flow after the external source of voltage has been removed. The energy to do this has been stored up by the inductor when the current was flowing through its windings. This energy is stored in the form of a magnetic field.

The inductor in this case is the traction motor windings.

Crown 1984 PF-5678-2 Rev. 3/84

ILLUSTRATION 4 SCR ON current flows through complete circuit.

ILLUSTRATION 5 SCR OFF current flows through flyback diode.

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MAINTENANCE As we recall, the speed is a function of the pulse frequency. Thus, at low speeds, when the frequency of pulses is low, the SCR is closed relatively infrequently.

Therefore, most of the motor current comes from the flyback current. However, when the speed is high, i.e. when the switch is closed much more frequently, the battery current forms the predominant portion of the motor current.

This situation is depicted graphically in Illustrations 6 & 7.

THEREFORE, UNDER ALL CONDITIONS, THE AVERAGE MOTOR CURRENT IS GREATER THAN THE AVERAGE BATTERY CURRENT (SEE ILLUSTRATIONS 6 & 7). AT LOW SPEEDS, THE MOTOR CURRENT MAY BE SEVERAL TIMES GREATER THAN THE BATTERY CURRENT. AT HIGH SPEEDS, I.E., WHEN THE SCR SWITCH IS OPEN FOR SHORT PERIODS ONLY, THE MOTOR CURRENT IS MADE UP ALMOST ENTIRELY OF BATTERY CURRENT. We mentioned before that the system uses a resonant charging circuit to switch off the SCR by reducing the terminal voltage to zero. Now, we are ready to understand exactly how this circuit works. The following description is illustrated by Illustration 8 to 14.

FIRST PULSE (ILLUSTRATIONS 8 & 9)

ILLUSTRATION 6

ILLUSTRATION 7 TO SUMMARIZE: WE HAVE ESTABLISHED THAT THE VERY FAST ACTION NECESSARY FOR THE OPERATION OF THE CONTROL IS ACHIEVED BY SWITCHING THE MAIN SCR “ON” AND “OFF” AT A VERY FAST RATE. THE “ON” STATE IS EASILY ACHIEVED

BY APPLYING A TRIGGER SIGNAL TO THE GATE AND THE “OFF” STATE IS ACHIEVED BY INTERRUPTING THE CURRENT FLOWING THROUGH THE SCR OR BY REDUCING THE TERMINAL VOLTAGE TO ZERO BY MEANS OF A RESONANT CIRCUIT.

ILLUSTRATION 8 When the driver places the FORWARD/REVERSE SWITCH in the FORWARD direction and provides a speed signal, usually via an accelerator, the forward direction CONTACTOR is energized. This connects the motor to the battery. At this time SCR1 is not conducting.

Immediately after the CONTACTOR closes the ELECTRONIC CONTROL MODULE which is usually referred to as the LOGIC UNIT, directs a TRIGGER pulse to SCR2. Current then flows from the battery through the motor and charges the capacitor.

Crown 1984 PF-5678-3 Rev. 3/84

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01 REV. 3/84

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MAINTENANCE When the capacitor is fully charged, the current flowing through the “off” SCR (SCR2) falls to zero and the SCR turns off. These actions serve to prime the circuit, and now the logic module directs a trigger pulse to the “gate” electrode of the main SCR. SCR1 is fired, becomes conducting and current starts to flow in the motor. This current rises slowly, limited by the motor and lead inductance.

ILLUSTRATION 10 This process is depicted graphically in Illustration 11.

Without the SCR in the circuit this process would continue and the energy stored in C1 would once again be transferred into L1 and so on, until all the energy was wasted as heat in the various parts of the circuit.

However, by virtue of the SCR’s electronic properties of not conducting in a reverse mode, the reverse charge on C1 is trapped by SCR3 turning off.

ILLUSTRATION 9 CAPACITOR CHARGE REVERSAL (ILLUSTRATION 10) After the desired “ON” time the Logic Unit instructs SCR3 (by means of a pulsed voltage to the gate) to turn on. As the SCR is fired into conduction current begins to flow in the circuit and the capacitor C1 discharges into the inductor L1. As the voltage on C1 decreases, the current in L1 increases. When C1 becomes completely discharged, there is no longer any voltage to increase the current in L1 and the energy which was stored in the capacitor is now transformed into magnetic energy in L1.

With no sustaining voltage, the magnetic field of the inductor begins to collapse. As it does so it generates a voltage which charges C1 once again, but this time in the opposite polarity. As the current in L1 falls to zero, all of its stored energy is returned to C1 so that it is now fully charged once again, this time with its polarity reversed.

Crown 1984 PF-5678-4 Rev. 3/84

ILLUSTRATION 11

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M4.2 - 06.5 - 004

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MAINTENANCE The reversed charge on C1 causes the self-firing circuit for the “OFF” SCR, SCR2 to fire after a short delay.

When this happens it effectively reverses the polarity of SCR1, current ceases to flow and SCR1 turns off.

(ILLUSTRATION 12)

ILLUSTRATION 13 Direction Contactor Arc Suppression:

ILLUSTRATION 12 TO REPEAT THE CYCLE (ILLUSTRATION 13) Because there is inductance in the circuit the motor current tries to keep flowing and circulates in the flyback diode loop. The battery leads also possess inductance which, combined with the motor inductance, cause a voltage which is higher than battery voltage to appear at the anode of SCR1. Because SCR2 is still in conducting mode this voltage is transferred to C1 and as soon as the capacitor is fully charged to this “peak” voltage, current ceases to flow and SCR2 turns off.

With C1 now charged, SCR1 is again triggered into conduction and the cycle repeats itself.

FEATURE DESCRIPTION Current Limit: (C/L) A current limit circuit is included and the setting is pre-set by means of a potentiometer. The current limit should never be increased above the rating specified for the Controller.

Plugging: (PLUG)

The equipment is designed to ensure that under normal operating conditions the making and breaking of the direction contactors occurs under almost zero current conditions thereby eliminating arcing. Under fault conditions, and in some cases when reversing with the bypass contactor operated, arcing can occur.

Ramp Start: Ramp start allows full SCR power to restart a vehicle from an incline without roll back when proper direction is selected.

Full Power Transition: This built-in feature provides smooth transition from SCR to 1A bypass. This is accomplished by the SCR continuing to pulse until the 1A contactor power tips close.

Controlled Acceleration (C/A) The accelerator shaping circuit takes the voltage feed from the accelerator potentiometer and shapes it to feed the desired voltage to the ON and OFF oscillators to give the correct pulse width and frequency. A delay circuit is incorporated in this circuit block so that smooth acceleration is obtained even if the accelerator control is suddenly fully actuated. The range of accelerator delay is adjustable over the range of .5 to 3.5 seconds.

Plugging is pre-set at our factory. However, this feature is adjustable. The Controller is designed to operate in the plugging mode, i.e., one can change direction with the accelerator and the plugging effort is dependant upon the accelerator control (twist grip) position.

Crown 1984 PF-5678-5 Rev. 3/84

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01 REV. 3/84

M4.2 - 06.5 - 005

M4.2 - 06.5 - 005

MAINTENANCE Static Return to Off: The clamp and sequence circuit takes inputs from the key, direction, foot, handbrake and seat switches (where fitted) and ensures that the contactors will not energize if the incorrect sequence is selected. It incorporates a static return to off time delay. This circuit also feeds inhibit signals to the oscillators to stop them oscillating and allow them to start up in the correct sequence.

Over-temperature Protection: The controllers include a thermal switch which measures the temperature of the main heat sink. At 85 degrees C the switch comes into the circuit to reduce current limit to a value = 2/3 of current limit.

Bypass Operation (1A Control): Bypass operation is included by connecting a bypass contactor into the circuit. Bypass operation under current limit conditions is normally inhibited unless the motor voltage is approximately 20% of battery voltage. Adjustments are provided for bypass over-current drop out and bypass pull in delay (variable over the range 0–10 seconds).

ILLUSTRATION 14 PE Models - (ILLUSTRATION 15) The limit switch card is used to place a variable amount of resistance in the oscillator circuit to limit the maximum speed the unit will travel in the SCR range when used as a walkie, but is bypassed by the high speed switch in the cross bar. This is used in conjunction with a diode block and relay (K1) also to control the speed away from the operator when the safety reversing switch is activated.

1A Plugging Holdoff: This built-in feature is designed to prevent 1A closure anytime during plugging.

Fault Detector Circuit: The fault detector circuit is designed to cause the direction contactors to de-energize if the main current carrying SCR has not been turned off within a pre-set period of time. As the controller never goes to a full-on condition except when using bypass, the fault detector circuit is always in operation. The fault detector circuit will also detect any condition which creates a short circuit across the main SCR including a welded bypass contactor, and in these conditions the forward or reverse contactor is prevented from closing.

Contactor Coil Suppression: Coil suppression circuits for the forward, reverse, and bypass contactors are included in the logic circuit. ADDITIONAL SUPPRESSION SHOULD NOT BE FITTED TO THE CONTACTORS. Additional optional contactors such as pump are suppressed externally to the logic unit.

AUXILIARY CARDS Limit Switch Cards (HIGH SPEED CARD) PC, TR, TWR Models - (ILLUSTRATION 14) The limit switch card is used to place a variable amount of resistance in the oscillator circuit to limit the maximum speed the unit will travel in the SCR range when operated as a walkie, but can be bypassed by the high speed switch.

ILLUSTRATION 15 Safety Switch Card (SSC) PE models only - (Illustration 28) The Safety Switch Card is used in conjunction with the safety reversing switch and associated relay (K1) to shorten the plugging distance when the safety reversing switch is actuated.

Under normal operating conditions, the normally closed K1 relay contact allows the plugging signal of D2 to be applied directly to the control module through PC1-11.

When the Safety reversing switch is actuated, the K1 relay contact opens, setting up the voltage divider circuit of the 3.3K and 6.8K resistors. This action provides a signal at PC1-11 which is more positive

Crown 1984 PF-5678-6 Rev. 3/84

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MAINTENANCE B. Tune-up

SSC-1

SAFETY SWITCH CARD 6.8K

D2 PLUGGING K1 DIODE

3832

SSC-2

3.3K

The following functions are all preset before units leave the factory. It may be necessary in some instances to adjust the settings in order to meet a particular truck requirement.

When readjustment is required the following procedure must be adhered to whenever a logic card is replaced. Refer to Illustration 16 for location of adjustments.

SSC-3

D1

INITIAL POTENTIOMETER SETTINGS

PC1-11

C/L C/A 1A PLUG

ILLUSTRATION 28

than that at the plugging diode, causing the plugging distance to decrease.

Full Full Full Full

CCW CW CCW CW

After the safety reversing switch is released the diode across the 6.8K resistor allows the system to return to normal operation. Without the diode, or with a bad diode, a low frequency pulsing will be evident, however, the truck will not move until the system is reset by turning the keyswitch “OFF”.

MAINTENANCE INSTRUCTIONS A. General The SCR control, like all electrical apparatus, does have some thermal losses. The semiconductor junctions have finite temperature limits above which these devices may be damaged. For these reasons, normal maintenance should guard against any action which will expose the components to excessive heat, such as steam cleaning; or which will reduce the heat dissipating ability of the control, such as restricting air flow.

The following DO’S and DON’TS should be observed: (1) Any controls that will be used in ambient of 100° F (40° C) or over should be brought to the attention of Crown.

(2) All external components having inductive coils must be filtered. Refer to Crown for specifications.

(3) The control should not be steam cleaned. In dusty areas, use low pressure air to blow off the control. In oily or greasy areas, a mild solution of detergent or denatured alcohol can be used to wash off the control and then blow completely dry with low pressure air. The control can also be cleaned with Freon TF degreaser.

(4) Terminal boards and other exposed SCR control parts should be kept free of dirt and paint which might change the effective resistance between points.

(5) The truck should not be plugged when the truck is jacked up and the drive wheels are in a free wheeling position. This can create excessive voltages that can be harmful to the control.

3833S

ILLUSTRATION 16

Current Limit (C/L) Current limit is set at a current high enough to ensure sufficient torque for the truck to operate under maximum safe load conditions yet low enough to prevent motor “burn-out”. To re-adjust the current limit set C/L fully counter-clockwise (a slight, clicking sound will notify this point) which will give maximum current limit - minimum motor current. Connect shunt in series with battery and connect meter. Set brake, place insulating material in 1A contactor tips and turn twist grip control to maximum speed. On PE, PC, PC”T”, and TWR model trucks, depress the high speed switch also. Observing the ammeter, turn C/L

Crown 1984 PF-5678-7 Rev. 2/94

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M4.2 - 06.5 - 007

MAINTENANCE NOTE

clockwise until 225 amps is obtained. Do not stall motor more than 30 seconds at a time and allow to cool between tests.

The following procedures refer to adjustments located on the limit switch card which is mounted on the electrical sub-panel. Refer to illustration 17 for placement of potentiometers on this card.

CAUTION

Under no circumstances should the panel current limit rating be exceeded or permanent damage to the unit will result. In order for the test to be valid, ensure that drive wheels remain locked and do not turn during this test.

NOTE All adjustments on the Control Card (C/A, plug, C/L and 1A time) are multi-turn potentiometers.

One turn may not be very noticable in the operation of the function.

Controlled Acceleration (C/A) This adjustment is a delay to maximum speed when full accelerator demand is suddenly applied. With the high speed switch depressed on PE, PC, TR, TWR and forks lowered on other trucks, move twist grip control rapidly to maximum speed. Adjust so a smooth, jerk-free increase in speed is demonstrated (approx. 1-1 1/2 seconds).

Turn C/A clockwise to increase rate of acceleration.

(Adjustable between .5 to 3.5 seconds) 1A Time 1A time is factory set for approximately 1 second and should never have to be adjusted. However, if it becomes necessary to change, observe the following procedure.

This adjustment controls the time between full speed and bypass operation. The delay time starts after the acceleration delay time has run up and is adjusted by turning the 1A potentiometer control clockwise to lengthen the delay.

Adjust for a smooth, jerk-free transition (approx. 1 second) from maximum speed to bypass speed. (Adjustable between .5 to 10 seconds.)

Plugging Plugging is the term used to describe a method of bringing the vehicle to a complete standstill and reverse the direction, in a controlled safe manner. Various factors affect the type of plugging response required, e.g. size of truck, environment, type of load to be carried, etc., and is best set under actual driving conditions. With high speed switch depressed on PE, PC, TR, TWR trucks and forks lowered on other trucks, run truck with bypass contactor pulled in for maximum speed. Move control handle rapidly to the maximum reverse direction. Adjust plugging so that truck stops in 11 to 13 feet. When turning the Plug Potentiometer CCW, plugging distance will decrease.

ILLUSTRATION 17 Walkie Speed (Limited Speed) (Turn adjustment clockwise to increase speed) PE, PC, TWR, TR trucks. Turn high speed switch off if used.

Move twist-grip control to maximum speed. Adjust so that empty truck travels 40 ft. in 7.40 to 9.10 seconds. (3.7 to 3.0 mph respectively) NOTE The Limit Switch Card adjustments, CS & LS, are single turn potentiometers. Attempting to turn more may damage the potentiometers.

Creep Speed (Turn adjustment clockwise to increase speed) PE, PC, TWR, TR trucks. Run truck with high speed switch off and with twist-grip control moved just enough so that truck moves. With twist-grip control in same position release high speed switch and adjust for same speed.

Crown 1984 PF-5678-8 Rev. 3/84

NOTE Truck must have acceleration distance of at least 40 feet before entering speed check.

NOTE After all adjustments have been set, seal cover with silicone rubber compound.

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MAINTENANCE TYPICAL PHYSICAL ARRANGEMENT AND IDENTIFICATION OF COMPONENTS (Refer to wiring diagram furnished with truck for precise arrangement of components.)

(1) Coil (L1)

(7) Resistor

(2) Resonant Charging SCR (SCR-3)

(8) Main SCR (SCR-1)

(3) Commutating Capacitor (C1)

(9) Thermal Protector

(4) Logic (Control Card)

(10) Turn-off SCR (SCR-2)

(5) JC1

(11) Flyback Diode (D1)

(6) PC1

(12) Plugging Diode (D2)

ILLUSTRATION 18

Crown 1984 PF-5678-9 Rev. 3/84

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MAINTENANCE POWER COMPONENT TEST AND REPLACEMENT If a power component is in need of removal for checking or replacement, the first two steps that should be taken are to disconnect the battery and discharge the commutating capacitor. (Located behind the upper left side of the logic card).

A simple method of discharging the commutating capacitor is to bridge its two mounting plates with a resistor.

Before servicing power components, a note of forewarning is in order: with the exception of power contactor lug nuts, panel hardware is metric. Servicing this unit requires 8mm, 10mm, 11mm and 13mm tools.

The following panel power connections have 13mm retaining nuts: A2, A1 and SCR Clamp.

ILLUSTRATION 20

The Main Power Heatsink has 10mm retaining nuts.

When testing the diode in the reverse direction, a reading in excess of 50k would be desirable.

The retaining nut for SCR3 is 11mm.

The control panel is laid out for easy access to all power components. If power components are to be replaced, ensure the specified torque-down requirements are met - and silicone grease applied, as directed - to prolong component life.

Replacement of Diodes 1. Disconnect diode clamp “A”.

Testing Diodes The plug and flyback diodes are identical. Their studs serve as anode (positive) connections and post as cathode (negative).

To check out a diode, the clamp should be disconnected from its post.

Diode testing with VOM is conventional, as shown in illustrations 19 and 20.

ILLUSTRATION 21 2. Using a suitable box wrench, loosen and remove defective device. Clean around face of heatsink and threaded portion of hole.

ILLUSTRATION 19 When testing the diode in the forward direction with a Simpson 260* (on RX1) a typical (good) reading would be less than 20 ohms.

3. Select a new device, lightly smear silicone grease around thread and contact face and by hand, screw into heatsink taking care not to cross or damage the thread. Tighten down with a torque wrench set at 20 to 23.5 lbs./ft. (27 to 32 N.m) pressure.

4. Reconnect clamp “A”. Unit is now ready for re-use.

Crown 1984 PF-5678-10 Rev. 3/84

Printed in U.S.A.

01 REV. 3/84

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MAINTENANCE SCR (Stud Type) Testing

NOTE

Both the SCR3 and SCR2 are stud type SCR’s, with the studs being the anode connections. Each can be tested while mounted on the control using a standard continuity (test) light.

1. Disconnect battery, and discharge capacitor.

2. Connect alligator clip from test lead to cathode (pigtail) of SCR. Easiest way is to clip onto capacitor’s bracket (to which the pigtail connects).

It is not necessary to remove light leads “D” when carrying out this operation.

3. Disconnect SCR2 gate lead at line connection “E”.

4. Using a suitable box wrench, unscrew and remove faulty SCR “A”. Make sure the vacant hole and area around are wiped clean at this stage.

3. Disconnect SCR’s gate lead from panel harness connection.

5. Select a new device* and lightly smear the threaded portion and contact face with silicone grease and replace into the heatsink by hand. Take care not to damage the threads. Tighten the SCR to a torque setting of 2.5 lb./ft. (3.4 N.m).

4. Connect a jumper wire from the probe end of the test light to the heatsink in which SCR2 is mounted.

6. Replace gate lead point “E” and cathode lead “B” to point “C”.

5. The test light should not be lit at this time.

7. Replace logic.

If the test light is lit, either SCR2 Drive or SCR3 Drive may be shorted. To isolate which is bad, disconnect the SCR3 Drive pigtail from its termination (it’s the easier of the two to get to) and recheck. Replace the component.

6. Assuming the test light did not light, momentarily touch the gate connection with the probe. The light should light and stay lit.

Unit is now ready for reuse. (*Check that it works properly before installing.)

Replacement of SCR3 1. Disconnect gate lead “D” at the “in-line” connector where it joins the yellow light lead in the panel harness.

Disconnect the jumper to the heatsink. The light should go out, and not relight with the jumper reconnected.

If the light never lit, check to be sure your test light works (a bright light when probe and test lead are connected). If the test light is good, change the SCR. Replacement of SCR2 1. Lift logic free of its grip mounting.

2. Unscrew locking nut on connection “C” and remove SCR cathode lead “B”.

ILLUSTRATION 23 2. Disconnect the cathode lead “E” at point “C”.

3. Unscrew locking nut “B”. Remove SCR “A” and clean up both faces of bracket “G” before refitting new device.

4. Lightly smear the contact face of new SCR “A” and replace.* Tighten locknut “B” to a torque setting of 2.5 to 3.5 lb./ft. (3.4 to 3.5 N.m) pressure.

5. Replace gate lead “D” and cathode lead “E” also replacing lead “F” on termination “C”.

Unit is now ready for reuse.

ILLUSTRATION 22

(*Check that the device works properly before installing.)

Crown 1984 PF-5678-11 Rev. 3/84

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MAINTENANCE SCR (Disc Type) Testing

2. Loosen nuts “C” evenly until clamp “A” is loose.

SCR1 Drive is a disc type device, and requires its two surfaces to be compressed in order to make (close) internal connections.

3. Apply slight upward pressure to shunt “B” and slide SCR “D” out.

To test the device, using a continuity (test) light: 1. Disconnect the battery and discharge the commutating capacitor. Disconnect the SCR1 gate lead from panel harness connection.

2. Connect the alligator clip on the test lead to Neg (-).

3. Connect a jumper from the probe to the heatsink on which SCR1 mounts.

4. The test light should not be lit. If it is, the SCR is shorted and should be replaced. (To be on the safe side, with the SCR out), recheck continuity from the heatsink to Neg (-). This will preclude the possibility of the circuit around the SCR having been shorted and making the SCR appear shorted.

5. Assuming the light did not light, momentarily touch the probe of the test light to SCR1 gate connection. The light should light, and stay on.

Remove the jumper to the heatsink, then reconnect it.

The light should go out and stay out.

As with SCR2 Drive and SCR3 Drive, the SCR1 Drive can become “LEAKY” and breakdown under load, but appear normal with a test light. Let the failure symptom help you decide whether or not to confirm/deny leakiness via substitution of a new part.

Replacement of SCR1 1. Remove gate lead.

4. Discard device 5. Select new device*, lightly smear anode and cathode with silicone grease and position SCR “D” between shunt “B” and heatsink “E” making positive to locate pin on shunt in the detent of SCR. 6. Position clamp “A” on threaded studs lining up pin on spacer with hole in clamp.

7. Assemble nuts “C” to threaded studs “F” and load clamp “A” evenly so nuts “C” are parallel.

8. Alternately tighten nuts “C” until clamp “A” is flat. This ensures that the correct mounting pressure is obtained.

9. Replace gate lead. *Test for proper operation before installation. To test, lightly compress SCR in a vise (otherwise you will read open circuit). Follow the test procedure for disc type SCR. Capacitor Testing The commutating capacitor can be tested, while still mounted on the control panel, with any VOM. To test: 1. Disconnect battery, and discharge the commutating capacitor.

2. Set your meter to at least RX 10k on a Simpson 260 meter.

3. Put meter leads on either side of the capacitor.

If it reads short circuit, remove the capacitor and test again. (To be sure the short was not in the circuit around the capacitor). If still shorted, replace it.

4. With the leads on either side of the capacitor, you should see a rapid increase in the “RESISTANCE” reading on the meter (as the capacitor charges).

The reading should exceed 50k. If it does not, remove the capacitor and recheck. If still low, replace it. If okay, check for a “LEAKY” SCR2 Drive (which prevented you for exceeding 50k).

ILLUSTRATION 24

5. Assuming the meter reading increased to greater than 50k, as expected, immediately reverse the leads on the capacitor.

You should see a rapid decrease in the “RESISTANCE” reading (as the capacitor discharges through the meter), followed by a rapid increase in the reading (as the capacitor recharges in the opposite polarity).

Crown 1984 PF-5678-12 Rev. 3/84

Printed in U.S.A.

01 REV. 3/84

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MAINTENANCE Replacement of Capacitor 1. Remove logic “A” from its grip mounting.

2. Remove nut “B” and loosen bolt “C”.

3. Lift logic mounting rack “D” and swing to the side.

ILLUSTRATION 25 4. Loosen nut “E”. Replace nut “B” and lock nuts “B” and “E” together.

ILLUSTRATION 26

5. Remove threaded stud.

6. Apply a slight upward pressure to shunt “F” and lift and remove capacitor “G”.

2. Remove connections at point “D” and retain bolt for reuse. Remove other coil lead from heatsink connection.

7. Before refitting new capacitor*, make sure that all surfaces are clean and free from dirt and grease. Install new capacitor and install the threaded stud. Make sure the threaded stud does not protrude under the mounting plate.

3. Loosen and remove coil fixing screw “C” and slide coil out from panel.

8. Replace parts “E”, “D” and “B”. Tighten nut “E”, using a torque wrench, to a setting of 10 lb./ft. (14 N.m) pressure. Tighten bolt “C” to a setting of 6 lb./ft. (8 N.m) pressure.

5. Replace connections at point “D” and on heatsink connection.

4. Insert new coil and replace fixing bolt “C”. Tighten with a torque wrench set at 6 lb./ft. (8 N.m).

6. Replace logic.

Unit is now ready for reuse.

9. Replace logic. (* Test to be sure it operates properly.)

Coil Testing Coil resistance is so low that an accurate resistive measurement (for a short circuit) cannot be made. However, a check can be made for an open circuit with VOM or continuity light.

Simply measure resistance (continuity) across the two coil leads. If open, replace coil.

Replacement of Coil 1. Lift logic “A” away from its grip mounting.

Crown 1984 PF-5678-13 Rev. 3/84

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01 REV. 3/84

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MAINTENANCE Thermal Switch Testing

AUXILIARY CARD TESTING

The thermal switch, which mounts between SCR2 Drive and SCR1 Drive on the main power heatsink, is a normally closed switch. When the heatsink temperature reaches 185 degree F. (85 degree C), the switch will open and effect a cut back in current limit.

High Speed Card (HSC)

To test, use either a VOM or continuity light to test for an open or short.

To test HSC, disconnect wires from the terminals to prevent parallel resistances from affecting the readings. The resistance checks between terminals 51-52 and 53-54 are for the CS and LS potentiometers. The readings, when turning the potentiometers through their range, should fall approximately within the limits in Chart 1.

Replacement of Thermal Switch 1. Remove light leads “B” and “C” from thermal switch.

2. Unscrew two fixing screws “A”, lift faulty switch away from heatsink and discard. At this stage clean the area of contact on the heatsink.

3. Select new thermal switch,* lightly smear base with silicone grease and fit to heatsink using two screws “A”.

4. Refit leads “B” and “C”.

Unit is now ready for reuse. (* Ensure switch is normally closed before installation.)

CHART 1 Safety Switch Card (SSC) To test SSC, disconnect wires from the terminals to prevent parallel resistances from affecting the readings.

When testing between terminals 1 and 2, a diode connected in parallel with the resistance affects the reading.

Chart 2 gives the directions necessary to obtain the approximate reading of the chart. Use a Simpson 260 or equivalent meter for the test between terminals 1 and 2.

If the reading is the same in both directions, the diode is bad and the SSC must be replaced. + meter lead on 1

– meter lead on 1

CHART 2

ILLUSTRATION 27

Crown 1984 PF-5678-14 Rev. 3/84

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01 REV. 3/84

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MAINTENANCE SCR MODULE PICTORIAL WIRING DIAGRAM

NOTE: THESE WIRES MUST BE IN CONTACT WITH THE SHUNT ON ITS TERMINATION.

TROUBLESHOOTING This section provides troubleshooting aids to facilitate analysis of truck failures.

Power components are easily accessed and can be checked with a volt-ohmeter (i.e. Simpson 260, or equivalent).

If power components are believed to be faulty, or in need of replacement, refer to Power Component Test and Replacement.

By using the appropriate troubleshooting aids (based on failure symptom), truck wiring diagram, and information provided in this manual; most problems should be easily detected and corrected.

WARNING

Drive wheels must be clear of the floor and free to rotate during all of the following checks unless otherwise specified. Care must be taken whenever doing “live” checks. At all other times disconnect the battery and discharge the commutation capacitor.

Crown 1984 PF-5678-15 Rev. 3/84

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01 REV. 3/84

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MAINTENANCE Voltage Readings

WARNING

The readings in Chart 3 are in reference to battery negative. When checking the points on the connectors of the SCR Control Module, make sure the meter probe is making good contact to the pin in the connector to ensure an accurate reading.

Drive wheels must be clear of the floor and free to rotate during all of the following checks. Care must be taken when doing these “live” checks to prevent possible personal injury.

CHART 3

Crown 1984 PF-5678-16 Rev. 3/84

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01 REV. 3/84

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MAINTENANCE TROUBLESHOOTING FLOWCHART BY SYMPTOM

(1) DIRECTION CONTACTORS DO NOT OPERATE

(Continued on Next Page) Crown 1984 PF-5678-17 Rev. 3/84

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MAINTENANCE

(2) DIRECTION CONTACTORS CLOSE — NO DRIVE

(3) DIRECTION CONTACTOR CLOSES - TRUCK MOVES A SHORT DISTANCE RAPIDLY FAULT DETECTOR CIRCUIT OPENS DIRECTION CONTACTOR

(Continued on Next Page) Crown 1984 PF-5678-18 Rev. 3/84

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MAINTENANCE

(4) DIRECTION CONTACTOR CLOSES - FAULT DETECTOR CIRCUIT OPENS DIRECTION CONTACTOR NO SUDDEN MOVEMENT - NO ARCING AT CONTACTOR

(5) TRUCK MOVES SLOWLY - WILL NOT ACCELERATE

(Continued on Next Page ) Crown 1984 PF-5678-19 Rev. 3/84

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MAINTENANCE

(6) TRUCK ACCELERATES - NO CONTROL WITH THE ACCELERATOR

(7) TRUCK ACCELERATES NORMALLY - BYPASS DOES NOT OPERATE

(Continued on Next Page ) Crown 1984 PF-5678-20 Rev. 3/84

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MAINTENANCE

(8) TRUCK STOPS VERY RAPIDLY WHEN ATTEMPTING PLUG BRAKING

(9)

DIRECTION CONTACTORS CLOSE — NO DRIVE AFTER SAFETY SWITCH RELEASED (PE MODEL TRUCKS ONLY)

NOTE

When this type of fault occurs it is possible that the main devices can be damaged. Before connecting unit after locating fault, check the main power components using the method described in the Power Component Test and Replacement section.

(10) FUSE BLOWN The following procedure should be adopted when checking out both blown power fuses or control fuses.

Disconnect battery and discharge main commutation capacitor.

Using a suitable meter reading resistance, check for short circuits between fuse connection and negative.

By isolating the various parts of the circuit connected to the blown fuse, trace the short circuit and rectify.

Certain faults e.g. short circuit field or armature, may also have damaged power components. Always check SCR’s, diodes and capacitors before connecting unit and switching on.

Crown 1984 PF-5678-21 Rev. 3/84

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01 REV. 3/84

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MAINTENANCE 150-AMPERE CONTACTORS DISASSEMBLY AND ASSEMBLY Two main categories of these contractors are used.

The single-pole normally open types, and the single-pole double-throw types which have one normally open and one normally closed contact (Illustration 4-19). The assembly and disassembly of these devices will be covered individually.

ILLUSTRATION 4-19

Single-pole, Double-throw Type (One Normally Open and One Normally Closed Contact)

ILLUSTRATION 4-20

Disassembly (Refer to Illustration 4-20 for exploded view and ‘parts index).

1. Remove all electrical connections and remove the contactor from the vehicle for easier servicing.

2. Loosen the four long bolts in each corner, remove the top contact retainer, and the long bolts.

3. Remove the two top stationary normally closed contacts.

4. Remove the two contact spacers.

5. Remove the two bottom stationary contacts.

6. Remove the armature and movable-contact assembly.

7. Remove magnet frame and coil from base.

8. Loosen and remove the 10 - 32 nut from the armature and movable-contact assembly using a 3/8” socket or nut driver. Note the order in which the parts are removed from the stud.

© Crown 1978 PF-3384-1

M4.4 - 11 - 021

Parts Index 1. Long bolt with #8 Iockwasher 2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20.

21.

Top contact retainer Top stationary contact Contact spacer Bottom stationary contact Armature and movable-contact assembly (Includes Indexes 7 thru 17) 10-32 nut No. 10 Iockwasher No. 10 flatwasher Movable-contact carrier Shim Movable contact Spring cup (snaps into 12) Contact spring Bottom stationary-contact support Armature Spiral return spring Magnet frame Coil Base Bus connector

Printed in U.S.A.

M4.4 - 11 - 021

MAINTENANCE Assembly (Refer to Illustration 4-20 for exploded view and parts index).

Before assembly, all parts should be cleaned, inspected for wear and replaced if required. Assembly is performed in reverse order from disassembly with the following precautions required: 1. Force the small end of the spiral spring over the small diameter on the armature assembly. (See illustration 4-22).

2. Reassemble the armature parts 7 to 17 and tighten the 10-32 nut to 14 to 18 inch-pounds torque (1.6 to 2.0 Newton meters).

3. Locate the projections on the magnet frame in the indentations on top of the coil with frame oriented as in illustration 4-20.

4. Add the armature and movable-contact assembly.

5. Properly seat the stationary contacts in the slots of the molded stationary contact support and add the two contact spacers.

6. Add the two top stationary contacts and top contact retainer. Insert bus connector before proceeding to Step 7.

7. Tighten the four long bolts in a uniform manner using a diagonal tightening sequence. Tighten the bolts with 14 to 18 inch-pounds torque (1.6 to 2.0 Newton meters).

DISASSEMBLY AND ASSEMBLY Single-pole, Single-throw Type (One Normally Open Contact) Disassembly (Refer to Illustration 4-21 for exploded view and parts index).

1. Remove all electrical connections and remove the contactor from the vehicle for easier servicing.

2. Loosen the four long bolts in each corner and remove the two contact spacers.

3. Remove the two stationary contacts.

4. Remove armature and movable-contact assembly.

5. Remove magnet frame and coil from the base.

6. Loosen and remove the 10 - 32 nut from the armature and movable contact assembly using a 3/8” socket or nut driver. Note the order in which the parts are removed from the stud. (See Illustration 4-21).

© Crown 1978 PF-3384-2

M4.4 - 11 - 022

ILLUSTRATION 4-21 Parts Index 1. Long bolt with #8 Iockwasher 2. Contact spacer 3. Stationary contacts 4. Armature and movable-contact assembly (includes Indexes 5 thru 15) 5. 10-32 nut 6. No. 10 Iockwasher 7. No. 10 flatwasher 8. Contact spring retainer 9. Contact spring 10. Movable contact 11. Shim 12. Movable-contact carrier 13. Stationary-contact support 14. Armature 15. Spiral return spring 16. Magnet frame 17. Coil 18. Base

Printed in U.S.A.

M4.4 - 11 - 022

MAINTENANCE Assembly (Refer to Illustration 4-21 for exploded view and parts index).

Before assembly all parts should be cleaned and inspected for wear and replaced if required. The assembly is performed in the reverse order from the disassembly with the following precautions required:

Contactor

Free Length “A” in inches (mm)

79567 79771 79772

0.73 to 0.79 (18.5 to 20.1)

83872 83872

0.67 to 0.73 (17.3 to 18.5)

1. Force the small end of the spiral spring over the small diameter on the armature assembly. (See illustration 4-22).

2. Reassemble the armature parts 5 to 15 and tighten the 10-32 nut to 14 to 18 inch-pounds torque (1.6 to 2.0 Newton meters).

3. Locate the projections on the magnet frame in the indentations on top of the coil with frame oriented as in Illustration 4-21.

4. Add the armature and movable-contact assembly.

5. Properly seat the stationary contacts in the slots of the molded stationary-contact support and add the two contact spacers.

6. Tighten the four long bolts with 14 to 18 inchpounds torque (1.6 to 2.0 Newton meters).

Contact Spring The free length should be between the limits shown in the table and should be replaced if it showns signs of having been overheated or of corrosion.

Contactor

Free Length “A” in inches (mm)

79567, 79771 79772, 83872

0.38 to 0.40 (9.6 to 10)

coils CAUTION

ILLUSTRATION 4-22

MAINTENANCE AND INSPECTION OF PARTS Contacts Contacts must be replaced before they have worn through contact button to the base copper material.

Spiral Return Spring The free length should be between the limits shown in the table and should be replaced if it shows signs of corrosion.

© Crown 1978 PF-3384-3

M4.4 - 11 - 023

The coils have voltage suppression cast integral with the coil. If a test voltage is applied in the wrong direction or if the coil is connected back wards, permanent damage may result. Observe the polarity mark on the coil during maintenance.

If the contactor fails to operate, measure the voltage being applied to the coil terminals. The coils on the contactor have been designed to actuate the contactor on reduced battery voltage and with approximately three volts drop in the electronic circuit so that all contractors should operate at or below 65 percent of rated battery voltage. Replace the coil if the contactor does not operate to the full stroke on 65 percent voltage or if the coil shows signs of being overheated.

Printed in U.S.A.

M4.4 - 11 - 023

ELECTRICAL SYSTEM Battery

Battery

Removal (Roll Out)

The care and maintenance of the battery is very important to get efficient truck operation and maximum battery life.

To remove a battery from a truck to a battery roller stand, park truck with brakes applied. Disconnect battery connectors- and remove battery side panels. Roll battery onto the roller stand which is the same height and as long or longer than the battery. Caution must be taken not to allow any metallic object to come in contact with the top of the cell, as this may cause a short circuit when the battery is rolled in or out of the truck.

Checking Battery electrolyte level should be checked before each charge of the battery. The level should be maintained at one-half inch above plates or just below the lower lip of the filler hole at all times. If low, add either approved local supply or distilled water (consult battery manufacturer) preferably at the end of charge. Do not overfill. For maximum battery life, specific gravity readings should be taken daily and recorded on a pilot cell.

The pilot cell should be changed on a monthly basis with readings taken on all cells at semiannual or annual intervals. Do not take specific gravity readings immediately after adding water. The water and electrolyte must be thoroughly mixed by charging before a reliable reading can be taken. The normal full charge specific gravity should be between 1.265 and 1.280.

Removal (Hoist) When the removal of a battery from a truck is required, park the truck with brakes applied and disconnect battery connectors. (On "SC" units the overhead guard has a chain access cutout to permit the use of an overhead crane or chain lift). Attach spreader bar to ends of battery and lift out. Caution must be taken not to allow any metallic object to come in contact with the top of the cell, as this may cause a short circuit when the battery is removed.

Crown 1978 PF3379-1 Rev. 10/06

Cleaning Always keep vent plugs tightly In place when cleaning battery. When properly watered and charged, the battery will remain clean and dry. All that is necessary Is to brush or blow off any dust or dirt which may accumulate on them. However, if electrolyte is spilled or overflows from the cell. it should be neutralized with a solution of baking soda and water (one pound soda to a gallon of water). To do this, remove the battery from the truck and clean with the solution of soda and water brushing the soda solution to get the solution beneath the connectors and removing the grime from the covers. Then rinse the battery with cool water from a low pressure hose to remove the soda and loosened dirt. If batteries stay wet consistently, they may be either overcharged or overfilled. This condition should be Investigated and corrected.

M4.6-11.0-001 01 Rev. 10/06

ELECTRICAL SYSTEM Battery Charging Charging requirements will vary depending on use of truck. Batteries discharged by more than one-third should be charged daily. If tees than one-third discharge, recharging should be delayed; however, they should be recharged at least once a week. If usage of truck makes it necessary, more than one battery should be available to provide ample power to the unit at all times.

CAUTION Never smoke or bring flame near the battery. Gas formed during charging is highly explosive and can cause serious injury.

Consult the charger manufacturer's manual covering your charger for hints on operation and maintenance.

Some of the basic rules are as follows: 1. Placing battery on charge: – Park truck at charging station with forks lowered and key removed.

–

Unplug battery from truck.

–

Be sure charger control is in the off position.

– Connect battery to charger and be sure connectors are mated all the way.

– Set timer for specified time. Set for Normal (Daily Charge, all except one night a week when the Equalize [Weekend] Charge should be used).

–

Check ammeter to be sure it shows charge.

2. Removing battery from charge: –

Be sure the charger is turned off.

– Break the connectors, using both hands with a straight pulling motion.

– Hang up the charger cable to prevent damage.

(Broken connectors can cause poor connections and connector failures).

–

Make daily battery checks.

– Connect battery to truck. Be sure connectors are mated all the way.

M4.6-11.0-002 01 Rev. 10/06

Crown 1978 PF3379-2 Rev. 10/06

MAINTENANCE

ILLUSTRATION NO. 1 DISCHARGE METER/LIFT INTERRUPT (BDI) The purpose of a “Discharge Meter/Lift Interrupt” is to monitor and protect the battery and electrical components of the lift truck. In order to operate your truck efficiently, you must know the capacity and state of charge of the battery during the time-of discharge.

Utilizing this information enables the battery to be recharged or replaced at the proper time, which is generally at 80% discharge or 1.74 volts per cell (VPC).

The “Curtis 933” is made up of two components, the meter and controller. REFER TO ILLUSTRATION NO. 1.

ILLUSTRATION NO. 2

Crown 1982 PF-5314-1

M4.6 - 11 - 100

Printed in U.S.A.

M4.6 - 11 - 100

MAINTENANCE METER OPERATION The meter indicates the state of charge of the truck’s battery. Equipped with a fully charged battery the pointer will move from “F" full charge - green area) towards ”E” (discharged -red area) as the battery is discharged. When the pointer moves to the solid yellow area the ’’reserve warning” light, in the meter, will start to flash. This means the operator has approximately 5% battery capacity available until the lift contractor will be locked out. If the truck is continued in operation with a “low” battery, the pointer will move to the red area and lift lock-out will occur preventing deep discharge and battery damage. As the discharged battery is recharged or replaced with a battery having at least 907. of full charge the interrupt will reset.

CONTROLLER OPERATION AND ADJUSTMENTS The controller, as designed for lift trucks, has been factory adjusted to settings that are satisfactory in most applications. The “reset-level” setting is “B”.

The “B” setting equals 2.1 VPC or 25.2 open circuit voltage for a 24 V battery or 37.8 open circuit voltage for a 36 V battery. The specific gravity (SG) of the battery at 2.1 VPC is approximately 1250. A battery meeting these conditions can be installed in the truck and the instrument will reset. A. battery with a lower VPC reading than 2.1 VPC may not reset at the “B” setting. A battery whose condition has declined due to age or poor maintenance may charge to a lower VPC reading and in order to utilize this battery it may be necessary to lower or decrease the “reset-level” of the controller. Example: A 24 V battery with a shorted cell may only read 23.1 open circuit volts, 2.1 x 11 = 23.1.

NOTE This adjustment should only be done to allow time to make necessary repairs to the battery.

Continued use could cause permanent damage to battery, charger and truck.

To adjust, remove the “pot” protector by hand turning in a CCW direction. Turn the shaft toward the “A” setting, this lowers the VPC requirement to a point that reset can be accomplished, 2.08 VPC, etc. Adjustments made from “B” toward “E” will increase the VPC required to reset, 2.125 VPC, etc. Battery condition, size, and the truck’s duty cycle must be taken into consideration if the “B” reset-level setting is not satisfactory.

Crown 1982 PF-5314-2

M4.6 - 11 - 101

ILLUSTRATION NO. 3 The “specific-gravity alarm” setting is “N”. This setting represents 1.74 VPC, 20.9 open circuit voltage for a 24 V battery, or 31.32 open circuit voltage for a 36 V battery. As the battery is discharged and reaches 1.74 VPC, the “specific-gravity alarm” will activate causing lift to be locked-out, preventing component and battery damage due to deep discharge. A 100% discharged battery will have a reading of 1.7 VPC. The 1.74 VPC represents 80% discharge. The recommended practice is to recharge batteries when they reach 80% discharge. The specific gravity at 1.74 VPC should be 1150. The adjustment from “N” toward “K” will decrease the VPC needed to activate the alarm.

Adjustment from “N” toward “P” will increase the VPC necessary to activate the “specific-gravity alarm”.

The trucks duty cycle, battery size and battery condition must be considered if the “N” setting is not sat is factory.

CAUTION Should a battery capable of reset be connected to the truck it will take approximately 10 seconds before the meter will read properly and reset to occur. If the discharged battery is then re-connected to the truck it will take 20 to 30 minutes before lock-out will occur, This additional discharge to the battery can cause severe component and battery damage due to deep discharge.

Printed in U.S.A.

M4.6 - 11 - 101

MAINTENANCE

ILLUSTRATION NO. 4 OPERATIONAL TEST

AMPERE-HOUR METER

An “1122E” tester can be used to check a malfunctioning instrument or a replaced meter and/or controller. Use the following procedure to run a satisfactory. operational test:

An “Ampere-Hour” meter monitors and displays current draw as it occurs and records the accumulated total ampere-hours used. The ampere-hour meter connects between the battery and the truck. With a properly charged battery in the truck, the truck is put through a duty cycle which represents the work it is required to perform during its shift. The elapsed time is recorded with a stop watch. From these figures it can be computed to determine when lock-out should occur. REFER TO ILLUSTRATION NO. 5.

(A) Disconnect the battery from truck.

(B) Install the ”1122E” switch according to illustration No. 4; the switch should be in the “OFF” position at installation.

Remove the leads from battery positive and lamp positive terminals from the controller. Secure these leads to the appropriate position on the “1122” tester. Connect the tester to the two terminals of the controller where the above leads were removed.

(C) Connect a fully charged battery to the lift truck.

Move tester switch to “RESET”. Meter should indicate full in approximately ten seconds. Check truck’s lift mode.

(D) Move tester switch to “RUN”. Meter should slowly move to the yellow area. The red warning light should flash as the pointer reaches the solid yellow. The pointer should move into the upper third of the red area after approximately 25 to 30 minutes. Check the truck for lift lock-out.

(E) Move tester switch to the “OFF” position and wait ten seconds. Move switch to “RESET”. The meter should indicate full. Check truck’s lift mode.

Function Run Lift 15” Place Back out Turn Run Turn Run Lift 1“ Run Lift 10” Side Shift Stack Load Totals

Time (seconds)

Accumulated Ampere-hours

10 12

30 8 2 2

.347 1.114 1.158 1.281 1.308 1.919 1.956 2.130 2.194 3.444 3.955 4.094 4.177

87

4.200

1

3 1 11

1

5 1

ILLUSTRATION NO. 5

NOTE if the operational test checks okay on a unit it may be beneficial to use an ampere-hour meter to determine ampere-hours used at interrupt.

Crown 1982 PF-5314-3

Printed in U.S.A.

M4.6 - 11 - 102

M4.6 - 11 - 102

MAINTENANCE

ILLUSTRATION NO. 6 A fully charged battery has a capacity rating by the battery manufacture; this is called ampere-hour rating, The amount of time it takes to discharge a battery depends on how hard the battery is worked.

High current rates or hard work cut down the discharge time. Example: A 226 ampere-hour (A. H.) battery is worked at a 452 amperes per hour rate. This battery will reach 100% discharge in 30 minutes. A 600 A.H. battery doing work at 100 amperes-hour will reach 100% discharge in 6 hours. REFER TO ILLUSTRATION NO. 6.

Only 80% of the rated capacity is available for actual work. At about 80% discharged, the voltage drops off

Crown 1982 PF-5314-4

M4.6 - 11 - 103

quickly causing high current draws that are harmful to the truck and battery. Batteries should be changed at 80% discharged.

Open circuit voltage and specific gravity are related as to how hard a battery is worked. Open circuit voltage and specific gravity reading will vary with different current rates. SG readings taken immediately after using a battery will change depending on the stabilization of the acid throughout the electrolyte, which can take up to 24 hours. This reading can drop as much as 20 points. However, the open circuit voltage may rise up to a tenth of a volt per cell. REFER TO ILLUSTRATION NO. 6.

Printed in U.S.A.

M4.6 - 11 - 103

MAINTENANCE To compute average current use the following formula:

Accumulated ampere-hours x

(EXAMPLE)

4.2

X

3600 sec./hr.

Total Time 3600 87

= Average current.

= 173.8

Refer to illustration no. 7 to determine the approximate worktime of a battery.

ILLUSTRATION NO. 7 To determine the approximate worktime of a battery at the average current rate use the following procedure: (A) Refer to the battery’s identification plate for the number of ampere-hours available. Example: 600 A.H. at the 6-hour rate.

(B) Divide the ampere-hours available by 6 to obtain average current. Example: 600-6 = 100 amperes.

(C) Divide the average current needed in the example used earlier, 174 amperes, by the 6-hour discharge

current, 100, to obtain the ratio of the average current required to the 6-hour discharge current.

(D) Use the graph in illustration no. 7 and 1.7 ratio equals 3 hours to reach 100% discharge and 21/2 hours of work time until 80% discharge is reached.

Lock-out should occur at approximately the time when the battery reaches 80% discharge. If the instrument is doing this it is operating correctly.

Crown 1982 PF-5314-5

Printed in U.S.A.

M4.6-11 - 104

M4.6 - 11 - 104

MAINTENANCE

TROUBLE-SHOOTING Symptom:

Remedy:

Gage will not reset.

Check battery state-of-charge, both voltage and specific gravity. The “B” setting equals 2.12 volts per cell. Batteries charged to 1265 or better will have this voltage. The “A” setting equals 2.055 volts per cell equaling a 1210 specific gravity. If a battery is not able to produce reset at the “A” setting, the battery and/or charger must be checked.

Truck comes in too soon for a battery charge.

Check specific gravity of battery when the meter light comes on. Do not turn the “specific gravity alarm” towards “K” if the specific gravity of the battery corresponds to more than 80% discharge (1140 for most batteries). More running time can be obtained by turning the specific gravity alarm from “N” setting towards “K”, providing the battery does not show 80% discharge.

Gage sticking.

Disconnect battery. Connect ohmeter to pin 2 and then tapping pin 3 with other lead. Do not clip onto pin 3, you might burn out the 1 milliampere meter movement. As you tap pin 3 the gage pointer will jump, if not, the meter should be replaced.

Gage will not return to exact location when power is removed and reapplied.

The Memory Cell in controller may be losing power. Replace or exchange controller.

“Reserve Warning Light” does not illuminate.

Check bulb, meter wiring, battery voltage.

“Reserve Warning Light” illuminates continuously.

Check battery voltage and meter.

Lift not locked-out when gage pointer enters red area of gage.

Check relay wiring, relay, and meter.

NOTE

The discharge meter/lift interrupt can be checked out on the truck with the use of a “1122” tester in approximately 30 minutes.

Crown 1982 PF-5314-6

M4.6 - 11 - 105

Printed in U.S.A.

M4.6 - 11 - 105

MAINTENANCE CURTIS MODEL 933/3 BATTERY DISCHARGE INTERRUPT (BDI) DISCHARGE N

1 2 3 4 5 6 7 8

O

P

M L C

K D

BATTERY

F INDICATOR

+

–

E 1/2

B

E

A

1/10

RESET

CURTIS 933 CURTIS CONTROLS DIVISION Manufactured in The USA

MODEL 933/3 Made in the USA Patent Pending This is a Static Sensitive Device Only Authorized Service Technicians

METER WITH POINTER

TWO WIRE METER (Red LEDs)

THREE WIRE METER (Red LEDs)

BDI/HOUR METER w/ 10 LED'S (Green & Yellow)

CONTROLLER 4245-01

ILLUSTRATION 4.6-1

The CURTIS MODEL 933/3 consists of two (2) components: the meter and the controller. Refer to Illustration 1.

The purpose of the Battery Discharge Interrupt (BDI), is to monitor and protect the battery and other electrical components of the lift truck. When the battery is not replaced or recharged at the correct time, generally at 80% discharge or 1.74 volts per cell (VPC), the battery will experience high current draws that will damage battery and electrical components. To avoid continued discharge at this level, a contact in the controller of the BDI which is placed in the lift pump circuit, opens and inhibits the lift function until the battery is recharged or a freshly charged battery is installed in the truck.

Meter Operation Your meter may have either an indicator pointer or LED levels.

The indicator pointer meter shows the state-of-charge of the battery. The pointer will move from the green ball (full charge zone) to the red ball (discharged zone) as the battery is discharged. As the pointer moves to the solid yellow area, a reserve warning light will begin to flash. This flashing light indicates approximately 5% battery capacity available before the lift contactors will be locked out. If the battery continues to be discharged, the pointer will move to the red ball zone. The red ball zone indicates lift lockout to prevent deep discharge of the battery and electrical component damage. When the battery is recharged or replaced with a fully charged battery, the meter will reset to the level of the recharged or replaced battery.

charged battery. If the battery continues to be discharged, the last LED will be turned on and the last two LEDs will flash alternately. Lift lockout will then occur until battery exchange or recharge takes place.

Controller Operation/Adjustment The controller, designed especially for lift trucks, has been adjusted at the factory to settings of "B" for reset and "N", for discharge. These settings have been found to be satisfactory in most industrial applications.

The reset setting of "B" equals 2.1 volts per cell (VPC), 25.2 open circuit voltage for a 24 volt battery, 37.8 open circuit voltage for a 36 volt battery. The specific gravity (SG) of the battey at 2.1 VPC is approximately 1250. As a battery charged to this level is connected to the truck the instrument will reset. A battery charged to less than 2.1 VPC will not cause reset. A battery's condition, or capacity, will decline due to age and/or improper maintenance and a 2.1 VPC reading is not possible. To utilize a battery in this condition it is necessary to make a reset adjustment toward "A". On the other hand, new batteries and batteries in better condition may necessitate a reset adjustment from "B" to "E". This adjustment will increase the VPC that are needed to reset the instrument; 2.125 VPC for example. Battery condition, battery size, and the truck's duty cycle must be considered before making any adjustment from the "B" setting.

Example: A 24 volt battery with a shorted cell may only read 23.1 open circuit volts; 2.1 VPC x 11 = 23.1.

NOTE

The LED meter also monitors the battery. When the battery is at full charge, the 1st LED is illuminated. As the battery discharges, the illuminated LED is turned off and the next LED is turned on. When the next to last is illuminated, the battery should be recharged or exchanged with a fully Crown 1982 PF-5315-1 Rev. 7/96

This adjustment should only be done to allow time to make necessary repairs to the battery.

Continued use could cause permanent damage to battery, charger and truck.

Printed in U.S.A.

03 REV. 7/96

M4.6–11.0–200

M4.6–11.0–200

MAINTENANCE A lower reset adjustment may be necessary. Remove the potentiometer protector by hand turning in a CCW direction.

Turn the shaft, with arrow on top, toward the "A" setting to lower or decrease the VPC necessary to allow reset to occur.

This decrease may be 2.08 VPC for example. Refer to Chart 1 for discharge and reset VPC settings.

DISCHARGE O P

INCREASE

N

M

L

K

The discharge setting of "N" equals 1.74 VPC, 20.9 open circuit voltage for a 24 volt battery, 31.32 open circuit voltage for a 36 volt battery. As the battery is discharged to 1.74 VPC, the discharge alarm will activate causing the truck's lift contactor(s) to be locked out. Lockout prevents deep-discharge of the battery causing battery damage and possible truck electrical component damage. The "N" setting, 1.74 VPC, represents 80% battery discharge; 1.70 VPC equals a 100% discharged battery. The 80% discharge point is the recommended point for battery recharge or replacement.

The specific gravity (SG) at 1.74 VPC is approximately 1150.

To change the discharge setting, remove the potentiometer protector by hand turning in a CCW direction. Turn shaft, with arrow on top, from "N" toward "K" to lower or decrease the VPC necessary to activate the discharge alarm and cause lift lockout. Adjustments made fron "N" toward "P" will increase the VPC needed to cause lift lockout. Consider the battery condition, battery size, and the truck's duty cycle before making any adjustments from the "N" setting.

CAUTION

D E

INCREASE

C

Should a battery capable of reset be connected to the truck it will take approximately 10 seconds before the meter will read properly and reset to occur. If the discharged battery is then reconnected to the truck it will take 20 to 30 minutes before lockout will occur. this additional discharge to the battery can cause severe component and battery damage due to deep discharge

B

A

WIRING DIAGRAM

RESET

Battery Positive 4055

ILLUSTRATION 4.6-2

Discharge Pot Setting VPC P O * N M L K Beyond K

1.82 1.78 1.73 1.68 1.63 1.57 1.56

Existing Lift Switch

RESET Pot Setting VPC E D C * B A Beyond A

Existing Lift Contactor Coil

Fast Test Input 4 5 3

Panel

2.18 2.15 2.12 2.09 2.06 2.00

Meter

Battery Connector Break Existing Connection

1 2 3 4 5 6 7 8

933/3 + Battery – Meter + Battery Led – Lift – Battery – Battery

Battery Negative 4054

ILLUSTRATION 4.6-3

* Factory Setting CHART 4.6-1

Crown 1982 PF-5315-2 Rev. 9/95

Printed in U.S.A.

01 REV. 9/95

M4.6–11.0–201

M4.6–11.0–201

MAINTENANCE To Battery Positive (+)

Controller Tester "1141"

"1142" Tester

DISCHARGE N

Button 1 2 3 4 5 6 7 8

2

8

O

P

M L C

K D

E

B A

RESET

CURTIS 933 CURTIS CONTROLS DIVISION Manufactured in The USA

MODEL 933/3 Made in the USA Patent Pending This is a Static Sensitive Device Only Authorized Service Technicians

Controller 4056

ILLUSTRATION 4.6-4

Operational Test Should a unit fail to function properly or be replaced by a new unit, a fast-run-down controller tester "1141", when used with "1142" tester, will cause the meter to go from "full" to "lockout" in approximately one (1) minute. The "1142" tester can be used alone and will cause the meter to go from "full" to "lock-out in approxomately 30 minutes. The following procedure should be followed when using the "1141" and/or "1142" testers: (A) Disconnect trucks' battery.

(E) If battery is completely charged the meter will go to "full". Check that the truck's lift mode is functional.

(F) Move the "1142" switch to RUN position, starting the normal 30 minute discharge. Push button on "1142" tester, speeding up the rate of discharge.

(G) As the pointer goes into the solid yellow zone the "reserve warning" light flashes. When the pointer reaches the red ball lift lockout takes place. Check truck's lift mode.

Refer to Illustration 4.6-4 For B & C. NOTE (B) Connect "FasTest 1141" to controller (black lead to terminal #8 of controller and blue lead to terminal #2 of controller).

(C) Disconnect the battery positive lead from terminal #1 of controller. Connect spade terminal of "1142" tester to terminal #1. Connect battery positive to screw terminal of "1142".

"1142" tester used by itself will necessitate an approximate 30 minute discharge time.

NOTE If the operational test checks okay on a unit it may be benificial to use an ampere-hour meter to determine ampere-hours used at interrupt.

(D) Move "1142" switch to RESET position. Wait ten seconds and connect battery to truck.

Crown 1982 PF-5315-3 Rev. 9/95

Printed in U.S.A.

01 REV. 9/95

M4.6–11.0–202

M4.6–11.0–202

MAINTENANCE Ampere-Hour Meter

Function

An "Ampere-Hour" meter monitors and displays current draw as it occurs and records the accumulated total amperehours used. The ampere-hour meter connects between the battery and the truck. With a properly charged battery in the truck, the truck is put through a duty cycle which represents the work it is required to perform during its shift. The elasped time is recorded with a stop watch. From these figures it can be computed to determine when lockout should occur. Refer to Chart 2.

A fully charged battery has a capacity rating by the battery manufacture; this is called ampere-hour rating. The amount of time it takes to discharge a battery depends on how hard the battery is worked. High current rates or hard work cut down the discharge time. Example: a 226 ampere-hour (A.H.) battery is worked at a 452 amperes per hour rate. This battery will reach 100% discharge in 30 minutes. A 600 A.H. battery doing work at 100 ampere-hour will reach 100% discharge in 6 hours. Low battery voltage causes contactors to chatter, sluggish motor starts and causes internal heating of the battery which shortens its life. Refer to Illustration 6.

Time (seconds)

Accumulated Ampere-Hours

Run Lift 15 in. (380mm) Place Back Out Turn Run Turn Run Lift 1 in. (25mm) Run Lift 10 in. (255mm) Sideshift Stack Load

10 12 1 3 1 11 1 5 1 30 8 2 2

0.347 1.114 1.156 1.281 1.308 1.919 1.956 2.130 2.194 3.444 3.955 4.094 4.177

Totals

87

4.200

CHART 4.6-2 1.265 S.G. 180.8 A.H. 1.245 S.G. 246 A.H. 1.220 S.G. 355 A.H. 1.195 S.G. 408 A.H. 1.180 S.G. 480 A.H. 1.169 S.G. 525 A.H.

Recommended Max. Discharge 80% Specific Gravity

% of Total Capacity at Given Rate to 6 Hr. Rate

1.300 1/2 Hr., 226 A.H., 452 Amps.

1.0 Hr., 330 A.H., 330 Amps.

1.270

2.0 Hr., 444 A.H., 222 Amps.

37.5%

3.0 Hr., 510 A.H., 170 Amps.

1.240

6.0 Hr., 600 A.H., 100 Amps.

49%

10.0 Hr., 656 A.H., 65.6 Amps.

1.210

74% 1.180 85% 1.150

0

10

20

30

40

50

60

70

80

90

100

100% 109%

% of Rated Ampere-Hour Capacity 4057

ILLUSTRATION 4.6-5

Crown 1982 PF-5315-4 Rev. 9/95

Printed in U.S.A.

01 REV. 9/95

M4.6–11.0–203

M4.6–11.0–203

MAINTENANCE Only 80% of the rated capacity is available for actual work.

At about 80% discharged, the voltage drops off quickly causing high current draws that are harmful to the truck and battery. Batteries should be changed at 80% discharged.

Open circuit voltage and specific gravity are related as how hard a battery is worked. Open circuit voltage and specific gravity will vary with different current rates. SG readings taken immediately after using a battery will change depending on the stabilization of the acid throughout the electrolyte, which can take up to 24 hours. This reading can drop as much as 20 points. However, the open circuit voltage may rise up to a tenth of a volt per cell. Refer to Illustration 6.

To determine the approximate worktime of a battery at the average current rate use the following procedure:

(B) Divide the ampere-hours available by 6 to obtain average current. Example: 600 ÷ 6 = 100 amperes.

(C) Divide the average current needed in the example used earlier, 174 amperes, by the 6 hour discharge current, 100, to obtain the ratio of the average current required to the 6 hour discharge current.

Example: 174 = 1.7 ratio 100 (D) Use the graph in Illustration 6 and 1.7 ratio equals 3 hours to reach 100% discharge and 2 1/2 hours of work time until 80% discharge is reached.

Lockout should occur at approximately the time when the battery reaches 80% discharge. If the instrument is doing this it is operating correctly.

(A) Refer to the battery's identification plate for the number of ampere-hours available. Example: 600 A.H. at the 6 hour rate.

To compute average current use the following formula: Accumulated ampere-hours x

(Example)

4.2 x

3600 sec./hr Total Time 3600 sec./hr 87

= Average current

= 173.8

Ratio of Current Drain to 6.0 Hr. Discharge Current

5

4

3

Capacity to 100% Discharge

2 Capacity to 80% Discharge (Work Time) 1

0 4058

1

2

3

4

5

6

7

Hours ILLUSTRATION 6

Crown 1982 PF-5315-5 Rev. 9/95

Printed in U.S.A.

01 REV. 9/95

M4.6–11.0–204

M4.6–11.0–204

MAINTENANCE Troubleshooting Symptom:

Remedy:

Gage will not reset.

Check battery state-of-charge, both voltage and specific gravity (SG). The "B" setting equals 2.12 volts per cell (VPC). Batteries charged to 1250 or better will have this voltage. The "A" setting equals 2.055 VPC equaling 1210 SG. If a battery is not able to produce reset at the "A" setting, the battery and/or charger must be checked.

Truck comes in too soon for battery recharge/change.

Check specific gravity (SG) of battery when the meter light comes on. Do not turn the SG alarm towards "K" if the SG of the battery corresponds to more than 80% discharge (1150 for most batteries). More running time can be obtained by turning the SG alarm from "N" setting towards "K", providing the battery does not show 80% discharge. Under no circumstances should the adjustment be made if the SG corresponds to more than 80% discharge at the 6 hour rate.

Gage sticking.

Disconnect battery. Connect ohmeter to pin 4 and then tapping pin 3 with the other lead. DO NOT slip onto pin 3, you might burn out the 1 millampere meter movement.

As you tap pin 3 the gage pointer will jump, if not, the meter should be replaced.

Gage moves erratically or bounces.

Probable cause is noise pickup from unsurpressed contactor coil(s). Check suppression circuits on all contactor coils and replace defective circuits. If all suppressor circuits are operational, the controller and or gage could be defective.

Reserve Warning Light does not illuminate.

Check meter wiring and/or battery voltage. Meter defective.

Reserve Warning Light illuminate continuously.

Check meter wiring and/or battery voltage. Meter defective.

Lift not locked out when gage pointer enters red area of gage

Remove wire from pin 6 on the controller and try to lift. If lift is functional problem is in truck wiring. If lift is not functional reconnect wire to pin 6. Connect either tester 1141 or 1142 or both to controller. Run gage to red ball. Verify gage light is blinking. Lift should not work. If lift does work, replace controller and gage.

Lift lockout occurring unusually early.

Run the lift motor and check the voltage directly across the (This condition only pertinent after the truck has been battery terminals. Repeat this check at terminals 1 and 8 on operating successfully for serval months with the fuel gage) the controller. The readings should be within 0.5 volts of each other. Possible causes: high resistance in truck to battery connector.

Specific gravity (SG) is very low at lockout.

This can occur with a lightly worked truck where there is very little lifting and a lot of travel. Make a course adjustment by turning the discharge pot from "N" to "P" and measure SG after several cycles of operation. Fine tune by turning back towards "O" if SG is to high.

Crown 1982 PF-5315-6 Rev. 9/95

Printed in U.S.A.

01 REV. 9/95

M4.6–11.0–205

M4.6–11.0–205

MAINTENANCE

ILLUSTRATION 1 DISCHARGE METER/LIFT INTERRUPT (BDI)

The purpose of a “Discharge Meter/Lift Interrupt” is to monitor and protect the battery and electrical components of the lift truck. In order to operate your truck efficiently, you must know the capacity and state of charge of the battery during the time of discharge.

Utilizing this information enables the battery to be recharged or replaced at the correct time, which is generally at 80% discharge or 1.74 volts per cell (VPC).

The “Anderson 850” consists of the meter, controller, and relay, refer to illustration 1.

TYPICAL WIRING DIAGRAM ILLUSTRATION 2 Crown 1982 PF-5392-1

M4.6 - 11 - 500

Printed in U.S.A.

M4.6 - 11 - 500

MAINTENANCE METER OPERATION

The meter indicates the state-of-charge of the truck’s battery. The pointer will move from “F” (green, full charge zone), towards the “E” (red, discharged zone), as the battery is discharged. As the pointer moves to the solid yellow area the “reserve warning light”, an LED in the meter, will begin flashing. This flashing light informs the truck’s operator there is approximately 8% battery capacity available before the truck’s lift contractor will be locked out. If the truck is continued in operation with a “low” battery, the pointer will move to the red zone, causing lift lockout, preventing deep discharge, and battery damage.

As the discharged battery is recharged or replaced with a fully charged battery the meter will reset to the level of the recharged or replacement battery.

prevents any further lifting operations. A battery at 80% discharged should have a volts per cell (VPC) reading of 1.74 VPC. A 24V. battery will have an open circuit voltage of 20.88. A 36V. battery will have an open circuit voltage of 31.32 at 80% discharged. A battery connected to the truck with higher voltage readings will cause the relay to close and lifting operations can continue as long as the battery remains above this level.

OPERATIONAL TEST Should a unit fail to function properly or be replaced by a new unit, a quick check of operation should be done before beginning to trouble-shoot.

NOTE If the operational test checks okay on a unit it may be beneficial to use an ampere-hour meter to determine ampere-hours used at interrupt.

RELAY OPERATION A signal from the controller will open the relay when the truck’s battery reaches 80% discharged and

TROUBLE-SHOOTING SYMPTOM

REMEDY

Pointer moves below “E” and light remains on constantly.

lCheck controller switch for voltage mismatch. Check for discharged or defective battery. Check meter.

Pointer moves below “E” and light does not come on.

Check for defective meter.

Pointer pegs above “F” without momentary deflection to “E”.

Check for stuck pointer.

I

Pointer remains at “F” without momentary deflection to “E”.

Check meter wiring. Check for defective meter.

I

I

Relay locks out lift when pointer is still in green area.

Short terminals #2 and #4 on relay. If lift still doesn’t operate, check relay wiring.

I

I

Relay doesn’t lock out lift when pointer enters red area.

Check relay wiring. Check for defective relay or defective meter.

I

I

Relay locks out lift as warning light comes on and pointer Check for defective meter. is not in red zone.

I

Pointer deflects during operation.

Check routing of meter wiring for magnetic interference.

Meter readings are questionable.

Check battery connector, cabling, & volts per cell.

Note: Two models of the “Anderson 850” have been installed on trucks. They look identical and operate basically the same but the meters and controls are not interchangeable. Trucks equipped with the latest style will indicate empty when not connected to power. For further information on identification contact your lift truck dealer.

Crown 1982 PF-5392-2

M4.6 - 11 - 501

Printed in U.S.A.

M4.6 - 11 - 501

MAINTENANCE MOTORS CAUTION

Disconnect battery before checking brushes.

The inspection of both the traction and pump motors should include checking the connecting cables for tightness at motor terminals and to be sure cables are not worn or damaged.

Remove the brush bands to inspect the commutator and brushes. Check the commutator for any discoloration that may show signs of raised bars or stalls. If it is glazed or dirty, clean with a strip of No. 00 sandpaper. Blow out all dirt and grit with compressed air.

CAUTION

Do not use emery cloth to clean commutator.

Check the brushes for chips, breaks, or oil-soaking. If any of these conditions exist, they must be replaced. If brushes are dirty, wipe with a clean, dry cloth to remove loose particles of dirt. Be sure the brushes slide freely in their holders and make full contact with the commutator.

Brushes that are worn beyond one-half their original length should be replaced.

Inspect the brush spring for signs of heating that may change the tension of the brushes on the commutator.

With brushes in place, be sure the spring and brush pigtails do not interfere with the brushes movement through its useable length.

Check motor for shorts between terminals and motor frame by use of an ohmmeter on a high resistance scale such as R x 10,000. If a reading of less than 50,000 ohms is observed, the source of trouble should be repaired before unit is placed into operation to prevent further future damage.

A. Traction Motor Removal - For ease of turning drive unit, place truck on blocks to remove weight of truck from drive unit.

1. Disconnect battery plug.

2. Remove all electrical connections from motor.

3. Remove brake drum, cone and key.

4. Remove two bolts accessible from motor side in drive unit.

Support motor and remove two bolts from brake side.

5. Remove motor.

Crown 1978 PF-3457

M4.7 - 12 - 001

B. Brush Replacement - To Remove Brushes 1. Disconnect battery plug.

2. Rotate drive unit until motor brush band is accessible.

3. Clean brush band area of motor and remove band.

4. Remove screws holding brush pigtails.

5. Disconnect brush springs or move to side (varies with motor Mfg.) 6. Remove brushes.

7. Check commutator for roughness and high spots. Turn commutator if required.

8. Install new brushes, fasten pigtails, and connect or secure brush springs.

9. Check that pigtails will not interfere with brush movement as the brush wears.

10. Replace brush band.

C. To Replace Motor 1. Lubricate seal in drive unit housing.

2. Install new gasket on motor end bell (use gasket sealer as required).

3. Replace motor and secure bolts.

4. Replace brake drum, cone and key. Torque brake drum bolts to 8–10 foot pounds.

D. Pump Motor and Brush Inspection 1. Disconnect battery plug.

2. Clean brush band area and remove brush band.

3. Clean dirt and carbon dust from winding and brush holder with low pressure air. Use a clean, dry cloth to clean commutator. (Do not use emery cloth).

4. Brushes should be replaced when they reach a length of 3/8 inch or will reach that length before the next scheduled inspection.

5. Check brush springs to see they maintain tension against the commutator equally on all brushes.

Printed in U.S.A.

M4.7 - 12 - 001

MAINTENANCE MOTOR INFORMATION CHART

Printed in U.S.A.

M4.7 - 12 - 002

M4.7 - 12 - 002

MAINTENANCE TROUBLE SHOOTING CHART 1. No lift or travel A. Power “on” light and discharge indicator (optional equipment) do not operate – check: 1. Battery connections 2. Control circuit fuse 3. Key switch 4. Control leads 2. No travel, but lift functions operational on EV1SCR system A. Contactors do not close – check: 1. Brake switch 2. Control leads 3. Refer to “SCR Maintenance and Operation” – trouble shooting, found elsewhere B. “F” or “R” contactor does not close – check: 1. “F” or “R” directional switch 2. Control leads 3. “F” or “R” contactor coil 4. Refer to “SCR Maintenance and Operation” – trouble shooting, found elsewhere C. Contactors close – check: 1. Power circuit fuse 2. Refer to “SCR Maintenance and Operation” – trouble shooting, found elsewhere

B. Contactor closes–check: 1. Pump motor fuse 2. Contactor tips 3. Pump Motor 4. Power cables 4. No push-pull, but lift operational – check: 1. Push-pull switch on valve 2. Push switch in control pod 3. Pull switch in control pod 4. Control leads 5. No tilt, but lift operational – check: 1. Tilt switch on valve 2. Control leads 6. No side shift, but lift operational – check: 1. Side shift switch on valve 2. Control leads 7. Power fuse(s) blow – check: 1. Power cables for shorts 2. Contactor for proper operation 3. Motors for shorts 8. Control fuse blows – check: 1. Control leads for damage and possible shorts

3. No lift, but travel functions operational A. Contactor does not close – check: 1. Raise switch 2. Contactor coil 3. Control leads

© Crown 1978 PF-3458

M4.9 - 12 - 001

Printed in U.S.A.

M4.9 - 12 - 001

MAINTENANCE BRAKE SYSTEM The brake system is designed to be released hydraulically by depressing the brake pedal. As the operator lets up on the pedal, a spring applies the brake by expanding the brake shoes inside the brake drum.

1. Adjustment - Braking force adjustment alone can be done if proper stopping distance can be obtained; if not, proceed with the switch and shoe adjustment.

When replacing shoes, always use both procedures.

A. Braking Force Adjustment To obtain the correct braking force setting, adjust the brake spring tension by either turning the adjusting nut in or out. Refer to Illustration 5-5.

Spring adjustments are to be made on an empty truck, traveling at maximum speed, on a level surface, in a specified direction. (See chart 5-6 for allowable stopping distances on specific series.)

3. Fluid - Brake fluid is added to the reservoir mounted on the operator platform. Reservoir should be filled to between 1 and 1 1/2″ from the top. Use Pure Super Heavy Duty Brake Fluid or equal.

4. Bleeding - It may become necessary to bleed the brake system to remove air trapped in the lines. Best results are obtained if the system is bled by the use of pressure bleeder such as K-D tools #255 or Wagner Lockheed # FL-444 Fluid Ball or equal. Lower platform to floor height. (Stockpickers only) Fill brake reservoir with brake fluid. A bleed valve is located at the end of the slave cylinder mounted on the drive unit housing. Attach a drain hose to the bleed valve for the purpose of catching and reusing excess fluid.

Preferably use a clear line so you can see air bubbles flow through line until clear. Attach bleeder to the brake reservoir.

CAUTION

Do not apply more than 50 P.S.I. to avoid damage and possible rupture of reservoir.

ILLUSTRATION 5-5

With the brake pedal in raised position, open valve on pressure bleeder. Now open bleed valve on slave cylinder approximately 1/2 turn counterclockwise.

Close bleed valve after all air bubbles have been forced out of the system and there is a steady flow.

(This may take between 2 and 3 minutes). Shut off valve on pressure bleeder, open bleed valve momentarily to release pressure, then disconnect pressure bleeder. Open bleeder once more to drain reservoir down to proper level, shut off, and remove drain line.

If a pressure bleeder is not available, the following procedure can be used:

CHART 5-6 B. Switch and Shoe Adjustment Place switch actuator of cylinder rod assembly (See Illustration 5-5) against button on cutout switch. Do not activate switch. Rotate brake lever clockwise until the brake shoes contact the brake drum. Adjust collar on brake rod to align with the hole in the brake lever and assembly. If the drum drags with the pedal in the released position, readjust collar.

2. Lines - Use care to avoid kinking the brake lines.

Permanent damage to the line will result if this occurs.

© Crown 1978 PF-3459

M5.0 - 12 - 001

Fill brake reservoir with brake fluid. A bleed valve is located at the end of the slave cylinder mounted on the drive housing. It is opened by turning the valve counterclockwise approximately 1⁄3 turn. With the reservoir filled, the pedal on the platform is depressed, then the bleed valve is opened. The pedal is released only after the bleed valve is again closed. This procedure should be repeated until a steady stream without entrapped air is obtained several times from the bleed valve.

CAUTION

Do not allow fluid in brake reservoir to drain so as to draw air into the system.

After the system has been bled, refill the reservoir to the recommended level.

5. Lining Replacement - When replacing brake shoe, it is necessary to position the brake springs so that the long hooks are not both connected to the same shoe: After replacement, adjust as described in the switch and shoe adjustment.

Printed in U.S.A.

M5.0 - 12 - 001

MAINTENANCE

ILLUSTRATION 5-12 MASTER CYLINDER

Master Cylinder Disassembly

Operation

1. Pull back the rubber dust cover (5) and remove the circlip (6) with a pair of long-nosed pliers. (REFER TO ILLUSTRATION 5-12

When the brake pedal is depressed the push rod (2) contacts the plunger (3) and forces it up the bore of the cylinder (1). (REFER TO ILLUSTRATION 5-12).

During the first 1/32 inch (0.8 mm) of push rod travel, the spring washer (4) under the valve head is allowed to resume its natural “bowed” shape and closes the port to the reservoir. As the plunger continues to move up the bore, fluid is forced through the brake lines to the slave cylinders.

When the brake pedal is released the plunger moves back with the return of the fluid and the final movement of the plunger compresses the spring washer, lifting the valve seal off its seat and opening the supply tank port. The fluid can now move unrestricted between cylinder and reservoir.

2. Remove the plunger either by shaking the cylinder or by compressed air pressure.

If seals are loose on the plunger and appear oversize, the system is probably contaminated. Compare the old seals with new seals from rebuild kit, DO NOT ALLOW NEW SEALS TO COME IN CONTACT WITH OLD. If the old seals are considerably larger, contamination is again likely and the system should be thoroughly flushed. All seals and hoses should be changed at this time.

3. Inspect the surface of the plunger for any damage of any kind.

If plunger shows any damage at all, the master cylinder must be replaced.

Crown 1979 PF-5027-1

Printed in U.S.A.

M5.4 - 14 - 001

M5.4 - 14 - 001

MAINTENANCE 4. Clean all parts thoroughly that will be reused. Compare parts of assembly with parts in the rebuild kit to determine which parts will be reused.

5. Place the cleaned parts onto a very clean work area.

6. Inspect the plunger and cylinder bore for visible score marks, ridges, and corrosion. Check the bore for smoothness to touch. Very minor imperfections may be eliminated. The use of a very fine emery cloth in the cylinder bore should be the only type of repair attempted to remove any roughness in the cylinder bore.

CAUTION

Removal of any material or anodizing from the cylinder bore during any attempted clean-up operation will cause the cylinder to malfunction.

7. If there is doubt as to the condition of the parts then replace master cylinder. Inspect all remaining parts to be sure they are in good working order.

Master Cylinder Reassembly 1. Use the new parts obtained from Rebuild Kit during reassembly. Lubricate the inner diameter of the new plunger seal with unused brake fluid and fit the seal to the plunger.

2. Fit the valve seal, smallest diameter leading, onto the valve head. Position the spring washer on the valve stem to that it “flares” away from the valve stem shoulder. (SEE ILLUSTRATION 5-13)

6. Smear the sealing areas of the rubber dust cover with grease and fit to the push rod. Position the dust cover on the cylinder body.

NOTE When connecting the push rod it is necessary to maintain the 1/32 inch (0.8 mm) gap between the push rod and the plunger when the push rod is fully returned. In applications where the pedal returns until stopped by the cylinder there is no danger, but when a pedal stop is used care must be taken to maintain proper gap.

7. Install master cylinders in truck, connect lines, and bleed system.

Slave Cylinder At such time when the master cylinders and the brake system require maintenance it is recommended the slave cylinder(s) be included in such maintenance. Providing the working surfaces of the cylinder bore and piston are in good condition, new seals from a Crown Service Kit may be used. If score marks, ridges or corrosion appear on plunger or in cylinder bore, the slave cylinder should be replaced. Slight imperfections may be eliminated with the use of very fine emery cloth. If there is any doubt as to condition of slave cylinder it should be replaced.

CAUTION

Removal of any material or anodizing from the cylinder bore during any attempted clean-up operation will cause the cylinder to malfunction.

Disassembly 1. Remove slave cylinder from truck and disassemble on a clean work area (REFER TO ILLUSTRATION 5-14

ILLUSTRATION 5-13 3. Connect the spring retainer to the spring and compress the spring until the valve stem passes through the keyhole in the spring retainer and engages in the center. Fit the spring subassembly the plunger and press the leaf of the spring retainer to secure. (SEE ILLUSTRATION 5-13) 4. Lubricate the plunger seal and the cylinder bore with unused brake fluid.

5. Insert the plunger assembly fully into the cylinder bore, valve end first, easing the entrance of the plunger seal. Position the push rod and retaining washer and fit the circlip into groove.

ILLUSTRATION 5-14

Crown 1979 PF-5027-2

Printed in U.S.A.

M5.4 - 14 - 002

M5.4 - 14 - 002

MAINTENANCE 2. The new parts in the service kit will indicate which used parts can be discarded. Clean all remaining parts and the cylinder with unused brake fluid. Inspect all other parts to be sure all other parts are in good working condition.

Chart Listing Master Cylinder, Slave Cylinder, & Rebuild Kit.

Assembly 1. Place the new seal on the piston with the flat back of the seal against the shoulder.

2. Lubricate the seal and the cylinder bore with new brake fluid and reassemble the cylinder. Smear the dust cover and the sealing areas with grease to help protect the internal parts.

3. Install slave cylinder to truck and bleed system.

Crown 1979 PF-5027-3

Printed in U.S.A.

M5.4 - 14 - 003

M5.4 - 14 - 003

MAINTENANCE STEERING SYSTEM – SSR The slip sheet truck is equipped with a manual steering system using reduction gears to improve steering ratio.

The system is coupled to the drive unit by means of a roller chain. Rotation of the steering wheel varies depending on the type of steering your unit is equipped with – either forward or reverse.

ILLUSTRATION 6-6 Forward Steering (Optional) Refer to Illustration 6-6 By rotating the steering wheel clockwise, the unit will turn to the right when traveling in the indicated direction of travel. When the steering wheel is turned counterclockwise, the unit will turn to the left.

ILLUSTRATION 6-5 Reverse Steering (Standard) Refer to Illustration 6-5 By rotating the steering wheel clockwise, the unit will turn to the left when traveling in the indicated direction of travel. When the steering wheel is turned counterclockwise, the unit will turn to the right.

© Crown 1978 PF-3460

M6.0 - 12 - 001

Linkage Adjustment With all components and linkage assembled except the steering roller chain, rotate the steering wheel and check for smoothness of operation. If the steering is rough or hard to turn, shift the universal joint up or down to a position where the steering operates smoothly. Tighten the set screws on the universal joint and then assemble the roller chain. (Refer to Illustration 6-7)

Printed in U.S.A.

M6.0 - 12 - 001

MAINTENANCE NOTE

Chain Adjustment

To obtain a more accurate steering adjustment, the lift truck should be elevated to a position where the drive tire will see about half of its normal load (weight).

The roller chain connecting the steering sprocket to the drive unit sprocket is to have no more than 1/2″ (12.7 mm) of play. Should the chain become loose, tighten the adjusting nut located between the steering sprocket and the drive unit sprocket (See Illustrations 6-8 and 6-9).

Periodical inspection of the idler sprocket nut should be made to prevent steering failure. Refer to threading diagram for proper roller chain installation.

ILLUSTRATION 6-7

Threading Diagram For Steering

ILLUSTRATION 6-8

ILLUSTRATION 6-9

REVERSE STEERING

FORWARD STEERING

Printed in U.S.A.

M6.0 - 12 - 002

M6.0 - 12 - 002

MAINTENANCE TORQUE GENERATOR The torque generator used in this unit consists of two elements in one housing; the gerotor (hydraulic motor) and the companion control valve. The two elements are interconnected by drive links to provide an emergency direct through drive in the event of a hydraulic failure.

The turning effort, (torque) is provided by the gerotor mechanism which consists of an inner star and outer ring.

The inner star has six teeth which orbit in a fixed outer ring with seven lobes. The orbiting effect is created by hydraulic pressure from the control valve to the chambers between the inner star and outer ring lobes and is transformed into a steady circular shaft motion through a double ended splined drive to the power end shaft. This creates a high torque at low R.P.M. The control shaft operates at the same speed as the output shaft. The control valve consists of three basic components: the valvebody, control sleeve, and control spool. There are no external lubrication points on the torque generator. The hydraulic motor and valve mechanism are lubricated on the inside by the hydraulic fluid passing through it.

Repairs to be made on the torque generator should be done in a clean area, and during disassembly the parts should be laid out and inspected, then assembled without any foreign material entering unit. All parts should be cleaned with a degreasing solution and air dried before assembly. Do not wipe any parts with rag or shop towel. A small piece of lint could cause a malfunction of the gerotor or valve mechanism.

Disassembly Before loosening cap bolts scribe a line parallel to the center line of the unit from the power end housing to the control end cap to assist in orientating the parts for reassembly. Note position of power end and control end shaft keyways. Drain oil from unit by rotating the control shaft several times. Place unit in a soft jawed vise with the power end shaft up. Remove the key from the keyway.

Now remove the seven socket head cap screws that secure the power end housing to the control housing. Lift off the power end housing and shaft assembly from the upper wear plate. Slide the power end shaft out of the housing and discard the shaft “O” Ring seal. Note position of the seal washer. Remove the power end drive from the gerotor set. Then remove the gerotor set and wear plates from the control housing and lay these parts out on the bench for inspection. Lift out the control end drive from the center of the control spool in the control housing. Now relocate the unit in the vise to a horizontal position and remove the key from the shaft keyway. Inspect and clean the control end shaft. Carefully remove the four socket head cap screws that secure the control end cap to the

© Crown 1978 PF-3389-1

M6.3–11–001

control housing. Slip off the control end cap and remove the static “O” Ring, shaft “O” Ring seal and seal washer from the control end cap. Now pull the control spool and sleeve out of the control housing. Carefully note the position of the centering springs and push the cross pin from the sleeve. Slide the control spool out of the control sleeve and remove the centering springs. If spool and sleeve are frozen in the control housing, discard the entire control valve assembly and replace. DO NOT replace or interchange control spool, control sleeve or control housing separately as these parts should be replaced in matched assemblies.

Careful inspection of all parts is essential for proper operation after assembly. The centering springs should be checked for abnormal wear or deformation. Check the gerotor wear plates for wear or scoring. A certain amount of polishing due to the rubbing action on the wear plates may occur and should not be taken for wear. If heavy wear is evident, wear plates should be replaced. These parts are precision matched to a fine finish and flatness which prevents high pressure leakage in this area. Inspect the control spool, control sleeve and control housing for scoring or uneven wear. These three pieces are select fit during original assembly and any undue wear or damage to any one part makes it mandatory that they all be replaced as a matched set. Inspect edges of cross pin holes in control sleeve and tapered holes in the control spool for burns or interruptions. These must be removed for proper valve operation. Check cross pin for snug fit in control sleeve, if not, replace. Inspect the stub shafts of the power end shaft and control spool for coupling wear and broken-out keyways. If wear is severe replace part.

Severe coupling wear generally indicates misalignment.

Assembly Insert the control spool into the control sleeve so that the spring slots will line up. DO NOT force these two together.

Due to a very close fit, it may be necessary to insert the spool from the opposite end. Install the two sets of centering springs back-to-back in the spring slots with the notched ends of the springs away from the shoulder of the spool. Center springs in slot so they do not stick out beyond the sleeve. Now insert cross pin. Carefully insert the control sleeve into the bore of the control housing the same procedure used to assemble the spool and sleeve.

Place new “O” Ring seals in the static “O” Ring seal groove and the shaft “O” Ring seal counter- bore of the control end cap. You will notice that the proper size “O” Ring appears to be too large and must be pushed in place. Place the seal washer in the counterbore adjacent to the seal. Install the control end cap over the shaft of the control spool with a twisting motion to prevent damage to the seal. Care should be taken to prevent the control spool and

Printed in U.S.A.

M6.3–11–001

MAINTENANCE sleeve assembly from sliding out of the control housing during assembly procedures. Align the control end cap with the previously scribed line and loosely secure the assembly with four socket head cap screws. Using the original scribed line to aid in relative position of these parts, place the wear plate on the lapped surface of the control housing aligning the larger holes of the wear plate with the tapped holes of the control housing. Observe the control end drive and note the slot in its spline. Insert the spline in control spool and rotate slightly until the slot drops on the cross pin through the spool. With this in place, assemble the gerotor inner star and outer ring and place them on the wear plate. Engage the splined end of the control end drive with the splined hole of the gerotor inner star. Note that it is important that the two teeth of the drive gear be directly in line with the valley between any two points of the inner star. If this alignment is not correct, unit will attempt to operate in reverse when operated with hydraulic pressure. Insert one end of the double ended splined power end drive into the gerotor inner star splined hole. Now place the other wear plate over the gerotor set.

Check power end housing to be sure it is clean. Lubricate shaft “O” Ring seal with clean oil and insert in power end housing “O” Ring counterbore groove. This “O” Ring will appear to be too large for its counterbore and must be pushed in place. Insert the seal washer in the counterbore. Insert the power end shaft into the power end housing with a twisting motion to prevent damage to the seal.

Place the power end housing and shaft over the power end drive splined end and rotate until splined joint is engaged. Check and align power end housing with scribed line. Clean and inspect the seven cap screws.

Apply a drop of grade C-Loctite to each screw, insert and thread them into the seven holes of the power end housing. Slowly tighten the seven cap screws evenly to a torque of 12 to 14 ft./lbs. If power end shaft does not turn freely after cap screws have been tightened, back off tension and retighten screw more even. Turn the unit over and tighten the four cap screws that secure the control end cap.

TROUBLE SHOOTING CHART FOR TORQUE GENERATOR 1. Slow Speed

2. Lack of Power a. Worn pump not delivering sufficient power—repair or replace torque generator. b. Low oil supply—fill reservoir to recommended level. c. Faulty relief valve—check pressure reading.

Replace relief valve.

3. Binding or Locking a. Misalignment of input or output shaft of steering unit—correct misalignment.

4. Oil Fluid Overheating a. Relief valve partially stuck open causing continuous bypass—repair valve. b. Insufficient oil supply—refill reservoir. c. Steering unit not recentering to neutral position.

Check and correct alignment of input shaft.

5. Input Wheel Creep or “Motoring” a. Broken or weak centering springs. Disassemble control end of unit and check springs by placing it on a flat surface and pressing it down to 1/16 inch, release and it should return to 7/32 inch when released. If spring is completely broken, disassemble complete unit and thoroughly clean all parts and reassemble. b. “Sticky” control spool and sleeve. Disassemble control end of unit and inspect for foreign matter or burns between spool and sleeve. Control spool must rotate freely in sleeve.

6. Oil Leaks a. Tighten all cap screws and replace shaft “O” Rings.

7. Output shaft attempting to operate in reverse of input shaft rotation or extreme chatter of input wheel after unit has been repaired. a. Incorrect reassembly of control sleeve and gerotor inner star orientation. Disassemble unit and reposition inner star one splined tooth on control end drive spline.

a. Worn pump—repair or replace pump. b. Pressure relief valve partially stuck in open position.

Disassemble, clean and repair pump. c. Kink or flattened hydraulic line to steering unit— replace line. d. Worn gerotor mechanism in torque booster— disassemble and replace part.

© Crown 1978 PF-3389-2

M6.3–11–002

Printed in U.S.A.

M6.3–11–002

LIFTING MECHANISM Lift Chain

Lift Chain Correct lift chain maintenance is necessary for the safe operation of the lift truck. It is necessary to do intermittent maintenance on the lift chains for the maximum service life. Incorrect maintenance intervals can cause unsatisfactory lift chain performance.

WARNING Falling loads can cause injury.

Lift chains, chain anchors, chain pins, and their attachments are safety components. Their failure can cause the load to fall, causing serious injury or death.  Replace damaged lift chains and their components with original spare parts before returning the lift truck to operation.  Always replace lift chains in pairs.

Cleaning and lubricating the lift chain See the INSPECTION AND LUBRICATION section for the applicable lubricant and planned maintenance intervals for the lift truck.

Note: The frequency of lubrication changes with the conditions of operation and environment.

Cleaning the lift chains Note: The initial factory lubricant on the lift chains prevents corrosion. Do not clean or remove the lubricant from the new lift chains.

Lubricating the lift chain Lubricate the lift chains at the specified maintenance intervals for maximum service life. A layer of lubricant between the chain components and on all lift chain surfaces is necessary to: – Decrease the wear on the joint

WARNING Cracks in the lift chains can cause injury Incorrect cleaning can cause cracks in the lift chain and can result in serious injury or death.  Do not clean lift chains with steam, cold cleaning agents, or agents that cause corrosion. This can damage the lift chains.  Clean the lift chains only with Crown chain and cable lubricant or Crown Premium chain and cable lubricant.

– Prevent corrosion – Decrease the frequency of turned pins – Decrease tight joints in the roller chain – Cause smooth lift chain movement – Decrease the lift chain tension Special tools and equipment: – Crown chain and cable lubricant, P/N 363107-001 – Crown premium chain and cable lubricant, P/N 363115-001 1. Spray the lubricant onto the lift chain.

WARNING Incorrect or missing safety procedures and safety equipment can cause death or injury.

Use the correct protective equipment and obey all safety procedures to do work on a lift truck.

2. See Figure 1. The oil must go into the lift chain joints (1).

– Lubrication on the lift chain and in the joints prevents wear and provides maximum service life.

 Obey all recommended safety precautions in the applicable Crown Service Manual.  Use the correct protective items, such as eye protection, work gloves, and safety-toe shoes.

Crown 2020 PF5856 Rev. 2/20

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147

LIFTING MECHANISM Lift Chain

1

1

Fig. 1 (33490)

Inspecting the lift chain See the INSPECTION AND LUBRICATION section for the applicable lubricant and planned maintenance intervals for the lift truck.

Checking the lift chains for wear

Fig. 2 (33491)

Special tools and equipment:

4. Replace the lift chain if the elongation is more than 3% or will be more than 3% before the next maintenance interval.

– Chain wear scale, P/N 106440, or steel tape measure As the lift chain bends on and off the pulleys, the joints gradually wear. Material wears off the outside diameter of the pin and the inside diameter of the holes for the pins on the inner plates. This wear causes the lift chain to elongate.

Measuring the lift chains for wear with a chain wear scale

– Do not repair a chain link by removing a worn section of a lift chain and installing a new piece.

– If the lift truck has two lift chains, replace both lift chains at the same time.

– If a part of the lift chain is worn, replace both lift chains at the same time.

1. Raise the forks 152 mm (6 in).

2. Select a section of the lift chain that moves over a pulley during operation.

3. See Figure 2. Measure the lift chain with a chain wear scale (1).

– Use Scale A for lift chains with a pitch of 19 mm (0.75 in) or 25 mm (1.0 in) – Use Scale B for lift chains with a pitch of 16 mm (0.625 in) Note: The pitch is the distance between the pins.

M7.5-18.0-002 10 Rev. 2/20

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Crown 2020 PF5856 Rev. 2/20

LIFTING MECHANISM Lift Chain Measuring the lift chains for wear with a steel tape measure 1. Raise the forks 152 mm (6 in).

2. Select a section of the lift chain that moves over a pulley during operation.

3. See Figure 3. Measure the lift chain pitch (1) from the center to the center of two chain pins of an outer plate.

Checking the lift chain elongation 1. Using the chain link number found in the Lift Chain Wear table, count the chain links on the lift truck.

2. See Figure 3. Measure the length (2) from the center of the first chain pin to the center of the last chain pin.

Note: The pitch is the distance between the pins.

3. Calculate the percent of lift chain elongation (x).

Percent of the lift chain elongation = [measured length /(new length/100)]-100 Example: The lift chain pitch is 25 mm (1.0 in). The Lift Chain Wear table shows that the new length for this lift chain pitch is 305 mm (12.0 in). The measured length with the steel tape measure is 309 mm (12.2 in). x = [309 / (305 / 100)] - 100 x = 309 / 3.05 - 100 x = 101.3 - 100 x = 1.3 In this example, the lift chain elongation is 1.3%.

4. Replace the lift chain if the elongation is more than 3% or if it will be more than 3% before the next maintenance interval. See the Lift Chain Wear table.

– Do not repair lift chains by removing a worn section of a lift chain and installing a new piece.

– If the lift truck has two lift chains, replace both lift chains at the same time.

– If a part of the lift chain is worn, replace both lift chains.

Fig. 3 (33492)

4. See the pitch value in the Lift Chain Wear table to find the number of chain links that are necessary for the measurement.

Lift Chain Wear Pitch

Chain Links

mm

in

25.4

1.0

19.05

New Length

Wear Limit

mm

in

mm

in

12

305

12.0

314

12.375

0.75

16

305

12.0

314

12.375

15.88 0.625

20

318

12.5

327

12.875

Crown 2020 PF5856 Rev. 2/20

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149

LIFTING MECHANISM Lift Chain Checking the lift chains for damage Lift Chain Inspection Damage Example

Damage and Symptom Noise •

•

Mild squeaking or loud creaking during opera- • tion

Joint corrosion •

Cause

•

Red or brown color (1) • in the joint area

1

Surface corrosion •

2

Red or brown color (2) on the connecting plates

•

Insufficient lubrication in the lift chain joints

Solution 1. Check the lift chain elongation.

When the lift chain goes • over the pulley the movement in the joints causes friction.

If the lift chain is within the tolerance level, clean and lubricate the lift chain.

•

If the lift chain elongation is out of the tolerance level, replace the lift chain.

Insufficient lubrication

1. Replace the lift chain.

Grease or oils that do not 2. Lubricate the lift chain. go into the joint 3. Increase the frequency of the planned maintenance intervals.

Insufficient lubrication or anti-corrosion

1. Remove the corrosion from the lift chain with the correct cleaning agent.

•

If it is not possible to remove the corrosion, replace the lift chain.

2. Check the lift chain for pitting and other corrosion.

•

If other pitting is found or corrosion, replace the lift chain.

3. Increased frequency for planned maintenance intervals is necessary because of the conditions in the operating environment.

Images and technical information provided with the permission of Rexnord Kette GmbH • www.rexnord.com Figures 28009, 28010, 28011, 28012, 28013, 28014, 28015, 28016, 28017, 28018, 28019, and 28020 are used in this table.

M7.5-18.0-004 10 Rev. 2/20

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LIFTING MECHANISM Lift Chain Lift Chain Inspection Damage Example

Damage and Symptom Rigid joints •

3

4

•

Cause

Solution

Insufficient lubrication

1. Replace the lift chain.

The lift chain joints do not return to the extended position easily.

2. Increase the frequency of the planned maintenance intervals.

Turned lift chain pins

•

•

Note: Turned chain pins are 2. Increase the frequency a result of rigid joints. of the planned maintenance intervals.

One or more chain pins (4) turned.

Loose lift chain pins •

5

•

The lift chain is not aligned correctly and is operating against mast sections or at the side of the pulley.

•

The lift chains tension is not equal.

The outer plates (6) are worn down.

6

Nicks or distortion •

Insufficient lubrication

1. Replace the lift chain.

1. Replace the lift chain.

One or more chain Note: Loose chain pins are a 2. Increase the frequency pins (5) are protruding. result of rigid joints. of the planned maintenance intervals.

Too much outer wear •

•

Insufficient lubrication

Parts of the lift chain have nicks (7) or are distorted.

•

1. Measure the width of the wear zone and calculate the percentage of wear in relation to the overall width of the plate.

•

If the wear is greater than or equal to 5% of the full width, replace the lift chain. Correct the alignment of the lift components and pulleys after replacing.

•

If the wear is less than 5% of the full width, correct the alignment of the lift components and the pulleys.

The lift chain hits against 1. Remove the cause of parts of the mast. the nicks or distortion.

2. Replace the lift chain.

7 Images and technical information provided with the permission of Rexnord Kette GmbH • www.rexnord.com Figures 28009, 28010, 28011, 28012, 28013, 28014, 28015, 28016, 28017, 28018, 28019, and 28020 are used in this table.

Crown 2020 PF5856 Rev. 2/20

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151

LIFTING MECHANISM Lift Chain Lift Chain Inspection Damage Example

Damage and Symptom Broken plates •

8

9

•

The head section of the plate is missing or • the crack is protruding.

Broken pins •

Cause

•

The outer plate (9) is lifted out a small distance

Solution

Fatigue crack because of 1. Find and correct the overload cause of the overload.

Corrosion

2. Replace the lift chain.

Pitting on the pins because of corrosion. Pitting permanently damages the pin.

1. Replace the lift chain.

1. Clean the lift chain and check for damage.

2. Increase the frequency of the planned maintenance intervals.

Note: These defects are not easy to see in the initial stages of inspection.

10

Contamination

•

Incorrect lubricant used.

•

•

The lift chain was not cleaned before lubrication.

A thick layer of dirt mixed with oil or grease (10) is on the lift chain.

•

If the lift chain is not damaged, lubricate it with the correct lubricant.

•

Replace the lift chain if it is damaged.

2. Increase the frequency of the planned maintenance intervals.

11

Hydrogen absorption

•

•

2.

Note: Electrolysis always makes hydrogen. Solvents made with chlorine also emit 3. hydrogen.

Non-distorting brittle fracture (11), only on the outer plate

Lift chain elongation •

•

The lift chain came into contact with hydrogen.

Wear caused by movement in the joints.

1. Replace the lift chain.

Check the operating conditions for sources of hydrogen.

See the cleaning the lift chains for instructions.

1. Replace the lift chain.

The lift chain elongaNote: Check if increasing tion check found the lift Note: This type of wear is the frequency of the chain to be out of the typical. planned maintenance intertolerance level. vals can increase the life of the lift chain.

Images and technical information provided with the permission of Rexnord Kette GmbH • www.rexnord.com Figures 28009, 28010, 28011, 28012, 28013, 28014, 28015, 28016, 28017, 28018, 28019, and 28020 are used in this table.

M7.5-18.0-006 10 Rev. 2/20

152

Crown 2020 PF5856 Rev. 2/20

LIFTING MECHANISM Lift Chain Replacing the lift chain 1. Find the part number for the lift chain in the service and parts manual. Make sure that the replacement lift chain is applicable to the lift truck.

Note: The lift chains must be replaced as a pair. Equal lift chain tension cannot easily be kept between the new lift chain and the existing lift chain.

2. If the lubricant dried or there is no lubricant, soak the new lift chains in heavy engine oil for a minimum of 30 min before installing.

3. After removing the existing lift chains from the mast, carefully examine the chain anchors and pulleys.

1. Use the grinding wheel to remove the top head of the pin (4) flush with the pin link plate (1). Be careful not to damage the pin link plate.

2. Put the flat washer (2) above the opening of the work surface.

– The flat washer holds the bottom pin link plate (1) and prevents damage to the lift chain components while pushing the pin through the lift chain.

3. Put the lift chain on its side and seat the pin in the flat washer (2).

4. Remove the pin from the lift chain through the top pin link plate (1).

4. Replace the chain anchors that are broken, cracked, or are worn.

3

5. Replace the pulleys that are worn and examine the pulley bearings for wear.

4

1

6. Do not paint the new lift chains.

7. Install the new lift chains with new pins. Do not use the existing pins.

8. After connecting the new lift chains to the chain anchors, adjust the lift chain tension for the correct fork or platform height.

– The correct lift chain installation and mast adjustment increase the service life.

Disconnecting a chain leaf

2 Fig. 4 (33505)

See Figure 4.

Special tools and equipment: – A stable work surface with an opening that is larger than the pin diameter. The work surface must be of sufficient thickness to let the pin (4) extend below the work surface to push it through the pin link plate (1) on the bottom.

– A flat washer (2) with an inside diameter more than the pin diameter and a height that is equal to the head height of the pin.

– A grinding wheel (3).

– A punch with a diameter that is less than the pin diameter.

– A hammer or press.

Crown 2020 PF5856 Rev. 2/20

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Notes:

154

MAINTENANCE SIDE SHIFT CYLINDER (Refer to Illustration 8-9) The side shift cylinder is mounted between the mast tilt carriage and the slip sheet assembly. By actuating the last (far right) control valve lever, the side shift cylinder will shift the complete slip sheet assembly two inches in either direction, from the centerline of the truck. In the event of excessive oil leakage around the cap end of the cylinder or its inability to shift the load, the following disassembly procedure should be followed.

Carefully remove the rod assembly, which includes the rod (item 8), piston (item 5), spacer (item 7) and gland (item 10), out the end of the tube assembly (item 1).

Inspect the tube assembly for any signs of scoring. If scoring is evident, the tube assembly must be replaced.

Rod Disassembly Fasten the cylinder mounting nut onto the gland end of the rod and tighten securely. Clamp the rod assembly, at the mounting nut, in a vise to prevent the rod from turning. Unfasten the piston nut (item 2) and slide the piston, spacer and gland off of the rod. Inspect the rod for any signs of scoring. If scoring is present, the rod must be replaced.

Seal Replacement With the use of a small hooked tool, carefully pull the seals from their mounting grooves.

CAUTION

Never use a screwdriver to remove seals, as damage and leakage may result.

After all seals are removed, inspect the contact surfaces on the piston and the gland for scoring. If slight scoring is evident, sand with a fine emery paper until high areas are removed. Heavily scored components must be replaced. After all parts are inspected, wash all cylinder components in a good grade solvent and dry with air pressure.

ILLUSTRATION 8-9

NOTE

Disassembly Before proceeding with disassembly, thoroughly clean the outside of the cylinder to remove all dirt and grease build-up. Place the cylinder in a vise. Care should be taken to avoid overtightening, as tube assembly (item 1) damage will result. With the use of an adjustable spanner wrench, similar to the one shown in Illustration 8-10, rotate the gland counterclockwise until the lockwire (item 14) is completely unwound from the inside of the cylinder. The lockwire should be discarded and replaced with one included in the seal kit.

When cleaning piston and gland, be sure to clean seal seating areas. Protect eyes and face when using compressed air.

After all parts are thoroughly cleaned, place in a dirt free area until ready for reassembly.

Cylinder Reassembly Apply a coat of hydraulic oil (Crown No. 63001-1) to all seals before they are assembled. Install all seals by hand. The nylon back-up rings (item 3 & 12) are cupped on one side so be sure the cupped side rests against the “O” ring (item 4 & 11). After the seals are installed, slide the gland and spacer onto the piston end of the rod.

When installing the piston and piston “O” ring (item 6), turn the piston in the direction of the threads to prevent “O” ring damage. Fasten the self locking nut after making sure that the piston is properly seated against the rod shoulder. After introducing the rod assembly into the tube assembly, insert the lockwire through the cylinder wall (at point “A”) and into the lockwire hole in the gland. Rotate the gland clockwise until the lockwire is fully seated in the tube assembly.

ILLUSTRATION 8-10

© Crown 1978 PF-3464

M8.9 - 12 - 011

Printed in U.S.A.

M8.9 - 12 - 011

MAINTENANCE MAST Your lift truck is equipped with a single stage mast assembly, constructed of hot rolled carbon steel channels.

Contoured alloy steel column rollers and side thrust rollers travel on the inside radii and outside faces of the mast channels. Lifting force is transmitted between the hydraulic lift cylinder and the tilt carriage by means of lift chains.

Unfasten the bolts which secure the stop blocks to the top, inside faces of the mast channels. Also unfasten the lift chains from their mounting blocks located on the back side of the tilt carriage. With the use of an overhead crane, lift the tilt carriage out through the top of the mast channels and place it aside of the truck.

Adjustment If it is determined that an excess of lateral tilt carriage movement is present, the tilt carriage column and side thrust rollers should be adjusted.

CAUTION

Before attempting adjustment, move the truck to an authorized maintenance area.

Column Roller After placing a pallet or a strong stable platform beneath the slip sheet assembly, lower the assembly until it comes to rest on the pallet or platform. Remove the quick-disconnect ball lock pins and retaining blocks from the bottom of the base assembly. Unfasten the mounting nut and positioning roll pin from the cap end of the side shift cylinder. Slowly actuate the side shift lever on the control valve until the cylinder unseats and is clear of its mounting flange. Tilt the tilt carriage forward to disengage the fork bar from under the mounting hooks. Lower the tilt carriage approximately 1″ (25.4 mm) and then tilt the carriage back to the home position.

CAUTION

Check to make sure the hoses connecting the slip sheet assembly are not stretched, pinched or damaged.

Unfasten and cap the two side shift hoses as well as the two hoses, which attach to the outside ports of the junction block located on the bottom of the rear pusher arm, from the lower side of the carriage. The tilt carriage can now be lowered to the bottom of the mast assembly where the remaining hydraulic hoses should be unfastened and capped. Unthread the six hoses from around the cylinder roller bar pulleys and place away from the working area.

CAUTION

Disconnect battery before proceeding with adjustments.

© Crown 1978 PF-3468-1

M7.0 - 12 - 001

ILLUSTRATION 7-4 Take a measurement between the two top and two bottom carriage column rollers, using an outside caliper similar to the one shown in Illustration 7-4. The column rollers are canted, so be sure to take the measurement on the correct portion of the roller (widest possible dimension). Once the measurement is obtained, lock the thumb screws. Now, using the inside caliper, measure the inside of the mast, along the area where column rollers will travel. After finding the narrowest contact point, lock the thumb screw and place the inside and outside calipers together to determine the amount of shims to be added to (or removed from) the column rollers.

NOTE When shimming column rollers, try to balance out the number of shims. (Example: 2 shims right, 2 shims left). If an uneven number of shims are required, mark the side to which the extra shim was added and install all other odd shims to that side. Also note that column roller shims come in two different thicknesses (1/32″ [0.8 mm] and 1/16″ [1.6 mm]), so if at all possible, vary shim thickness to avoid the uneven situation.

Printed in U.S.A.

M7.0 - 12 - 001

MAINTENANCE Once shimming is completed, clean the inside of the mast channels and apply a light film of multi-purpose grease (Crown No. 63002-7). Reintroduce the tilt carriage into the mast assembly and check running clearance. When the column rollers are properly adjusted, they should leave a mark in the grease on both radii of the mast channels.

CAUTION

The mast stop blocks must be installed at this time.

CAUTION

Never rotate the roller studs forward (to a tighter position) as roller bearing damage may result.

Insert the roll pins through the mounting bracket and into the appropriate hole in the roller stud. Retighten the cap screws and cycle the carriage to check running clearance. As a rule of thumb, the maximum side thrust roller clearance due to load cocking should not exceed 1/8″ (3.2 mm).

Rethread the six hydraulic lines over the roller bar pulleys and attach them to the bottom of the tilt carriage. The lift chain can also be reattached. Reverse the procedures mentioned earlier in this section for the reassembly of the hydraulic hoses, side shift cylinder and the slip sheet assembly.

Side Thrust Rollers (Refer to Illustration 7-5) To adjust the side thrust rollers, the roll pins, which lock the eccentric roller studs in position, must be removed.

At this time, the cap screws should also be loosened slightly. With the tilt carriage at the bottom of the mast, adjust the two outside (lower) side thrust rollers on their eccentric studs until the rollers contact the outside face of the mast. Tighten the two corresponding cap screws.

Run the tilt carriage to the top of the mast and adjust the two inside (upper) side thrust rollers until they come in contact with the inside lip of the mast, then tighten their two cap screws. Sight through the carriage bracket roll pin holes while rotating the roller studs back until the next closest roll pin hole in the roller stud is lined up with the sight holes.

ILLUSTRATION 7-6 Platen Height (Refer to Illustration 7-6) Lower the slip sheet assembly to the bottom of the mast.

At this point, the hydraulic lift cylinder should be completely bottomed out. To obtain an accurate measurement, the slip sheet platen (base assembly) must be in a perfectly horizontal position. By either loosening or tightening the chain anchor assembly located on the center mast cross member, the correct heel height of 5-7/8″ ± 1/8″ (129 mm ± 3.2 mm) can be achieved.

ILLUSTRATION 7-5

© Crown 1978 PF-3468-2

M7.0 - 12 - 002

Printed in U.S.A.

M7.0 - 12 - 002

MAINTENANCE Lift Chains The lift chains on your truck were designed for efficient, reliable transmission of lifting force from hydraulic cylinder to the forks. Safe, uninterrupted use of your lift depends on the proper care and maintenance of the lift chain.

After every 100 hours of truck operation, lift chains should be inspected and lubricated. When used in an extremely corrosive environment, inspect chains every 50 working hours. During inspection, check for the following: A. Wear Chain wear (stretch) develops as the joints wear.

Allowable wear (stretch) length is not to exceed 3%. On Crown 16 pitch lift chains (73991), when 16 pitches measure 12.375″ the chains must be replaced as a pair.

Note that 16 pitches of new chain measures 12.000″.

B. Rust and Corrosion An oil film must be present on lift chains at all times.

Never degrease or steam clean chains.

C. Cracked Plates Fatigue cracks, when found, are almost always located through the pitch holes perpendicular to the

© Crown 1978 PF-3468-3

M7.0 - 12 - 003

pitch line. Stress-corrosion cracks will be found on the ends of individual links and will point to the adjacent pin. If chain inspection reveals either type of crack, both chains must be replaced.

D. Tight Joints All joints must flex freely. Inability to flex indicates an inadequate lubrication schedule.

E. Protruding or Turned Pins Excessive loads and inadequate lubrication will cause the press-fit pins to rotate. Turned pins can be quickly spotted because the flats on the “V” heads are no longer in line. Left uncorrected, these pins will eventually work out and could cause severe damage and extended downtime. Never drive pins back into position, chains must be replaced as a pair.

F. Chain Anchors and Pulleys An inspection of your chain system should include a close examination of chain anchors and pulleys. Also, whenever checking or adjusting chains, make sure the cotter pins in the chain anchors are used and spread properly.

Printed in U.S.A.

M7.0 - 12 - 003

MAINTENANCE PUSH-PULL CYLINDERS (Refer to Illustration 8-11) The two push-pull cylinders are located directly below the front push arms and mount between the torque bar and the push rack. The push-pull cylinders are hydraulically tied in with the clamp cylinders by means of a sequence valve which actuates the cylinders in the proper succession. In the event of excessive oil leakage around the cap end of the cylinder or its inability to push off or pull on a specific load, the following disassembly procedure should be followed.

1). Inspect the tube assembly for any signs of scoring. If scoring is evident, the tube assembly must be replaced.

CAUTION

Never slide the gland over the knurled section of the rod, as seal damage will result.

Rod Disassembly Fasten a nut to the gland end of the rod and tighten securely. Clamp the rod assembly, at the nut, in a vise.

This will prevent the rod from turning when unscrewing the piston locknut (item 2). If a nut of that size is unavailable, simply grip the rod at the knurled section with a pliers or channel lock. Unfasten the piston nut (item 2) and slide the piston, spacer and gland off of the rod. Inspect the rod for any signs of scoring. If scoring is present, the rod must be replaced.

Seal Replacement With the use of a small hooked tool, carefully pull the seals from their mounting grooves.

CAUTION

Never use a screwdriver to remove seals, as damage and leakage may result.

ILLUSTRATION 8-11 Disassembly Before proceeding with disassembly, thoroughly clean the outside of the cylinder to remove all dirt and grease build-up. Place the cylinder in a vise. Care should be taken to avoid overtightening, as tube assembly (item 1) damage will result. With the use of an adjustable spanner wrench, similar to the one shown in Illustration 8-12, rotate the gland counterclockwise until the lockwire (item 12) is completely unwound from the inside of the cylinder. The lockwire should be discarded and replaced with one included in the seal kit.

After all seals are removed, inspect the contact surfaces on the piston and the gland for scoring. If slight scoring is evident, sand with a fine emery paper until the high areas are removed. Heavily scored components must be replaced. After all parts are inspected, wash all cylinder components in a good grade solvent and dry with air pressure.

NOTE When cleaning piston and gland, be sure to clean seal seating areas. Protect eyes and face when using compressed air.

After all parts are thoroughly cleaned, place in a dirt free area until ready for reassembly.

Cylinder Reassembly

ILLUSTRATION 8-12 Carefully remove the rod assembly which includes the rod (item 8), the piston (item 5), the spacer (item 6) and the gland (item 9) out the end of the tube assembly (item

© Crown 1978 PF-3465

M8.9 - 12 - 021

Apply a coat of hydraulic oil (Crown No. 63001-1) to all seals before they are assembled. Install all seals by hand. The nylon back-up rings (item 4) are cupped on one side, so be sure the cupped side rests against the “O” ring (item 3). After the seals are installed, slide the gland and spacer onto the piston end of the rod. When installing the piston and piston “O” ring (item 7), turn the piston in the direction of the threads to prevent “O” ring damage. Fasten the self-locking nut (included with seal kit) after making sure that the piston is properly seated against the rod shoulder. After introducing the rod assembly into the tube assembly, insert the lockwire through the cylinder wall (at point “A”) and into the lockwire hole located in the gland. Rotate the gland clockwise until the lockwire is fully seated in the tube assembly.

Printed in U.S.A.

M8.9 - 12 - 021

MAINTENANCE CLAMP CYLINDERS (Refer to Illustration 8-8) The three clamp cylinders are located in the push rack and when extended, grip the edge of the cardboard slip sheets. The clamp cylinders are hydraulically tied in with the push-pull cylinders by means of a sequence valve which actuates the cylinders in the proper succession. In the event of excessive oil leakage around the cap end of the cylinder or the lack of gripping power, the following disassembly procedure should be followed.

Inspect the tube assembly for any signs of scoring. If scoring is evident, the tube assembly must be replaced.

The tube assembly should be honed to remove any remaining retaining ring burrs.

Rod Disassembly Clamp the machined flats, located on the end of the rod, in a vise. (Flats not shown on Illustration 8-8.) Remove the cotter pin and the piston locknut and slide all components off of the rod. Inspect the rod for scoring. If scoring is evident, the rod must be replaced.

Seal Replacement With the use of a small hooked tool, carefully pull the seals from their mounting grooves.

CAUTION

Never use a screwdriver to remove seals as damage and leakage may result.

After all seals are removed, inspect the contact surfaces on the piston and the gland for scoring. If slight scoring is evident, sand with a fine emery paper until the high areas of the scoring are removed. Heavily scored components must be replaced. After all parts are inspected, wash all cylinder components in a good grade solvent and dry with air pressure.

NOTE ILLUSTRATION 8-8 Disassembly Before proceeding with disassembly, thoroughly clean the outside of the cylinder to remove all dirt and grease buildup. Manually extend the cylinder rod (item 7) from the cylinder and place tube assembly (item 1) in a vise. Care should be taken to avoid over-tightening as tube damage will result. Remove the four bolts (item 13) from the retainer (item 12) and slide the retainer up the rod to a position just below the rod end flats (not shown in Illustration 8-8).

NOTE Do not remove any components from the rod at this time.

Insert the blade of a small dull screwdriver under the end of the retaining ring (item 10) and pry out and up from its mounting groove. Slide the screwdriver around the tube, working the retaining ring out as you go. Avoid scratching the cylinder tube assembly bore. Before removing the rod assembly, push the gland (item 9) down into the cylinder, away from the retaining ring groove area. Using a scraper or similar tool, remove any raised material or burrs from the edge of the groove. If burr is not removed, piston removal may be difficult.

Carefully remove the rod assembly which includes the gland (item 9), the rod (item 7), the piston (item 6), the locknut (item 2) and the cotter pin (item 3) as well as the retainer (item 12) out the end of the tube assembly. © Crown 1978 PF-3463

M8.9 - 12 - 001

When cleaning piston and gland, be sure to clean seal seating areas. Protect eyes and face when using compressed air.

After all parts are thoroughly cleaned, place in a dirt free area until ready for reassembly.

Cylinder Reassembly Apply a coat of hydraulic oil (Crown No. 63001-1) to all seals before they are assembled. Install all seals by hand. If the teflon seal (item 4) which goes over the “O” ring (item 5) is hard to install, warm the seal slightly (not in excess of 100° F. [38° C.]). Care must be taken to avoid stretching the seal out of shape.

NOTE The rod seal (item 11) must be installed with the “O” ring facing the piston end of the rod assembly. The rod wiper (item 14) must be installed with the lip away from the piston end of the rod.

Install the retainer (with wiper away from piston end of rod), retaining ring and gland onto the piston end of the rod. Install piston and self locking nut. Make sure the piston is fully seated against the rod shoulder before tightening the locking nut. Insert the rod assembly into the tube assembly making sure the teflon seal remains in its groove and covers the “O” ring. Slide the gland into the tube assembly just slightly past the retaining ring groove in the tube assembly. Insert retaining ring and fasten retainer to gland with four cap screws.

Printed in U.S.A.

M8.9 - 12 - 001

MAINTENANCE

ILLUSTRATION 9-1 SLIP SHEET ASSEMBLY The slip sheet assembly on your truck is designed to load, transport and deposit materials which are stacked on slip sheets. After the truck has been positioned in front of the load, the side shift cylinder should be actuated if the load is not centered with the platen. Once centered, the pushpull cylinders should be extended to a position where the slip sheet tab is fully engaged in the gripper bar. By shifting the control lever to “retract”, the gripper will clamp the tab and then the load will be pulled onto the platen. After the load has been transported to its designated destination, the control lever should be shifted to “extend.” The gripper bar will open and then the load will be pushed off of the platen. The truck must be backed away from the slip sheet tabs before the control valve is shifted to retract the push rack or the tab will be reclamped.

INSPECTION CHECKS Push Rack Alignment

of the entire unit. Push rack misalignment is usually caused by one push-pull cylinder extending farther than the other. This condition should be corrected as soon as possible to prevent damage to the linkage mechanism.

Periodically inspect the alignment by extending the push rack to the end of the platen and measuring the distance from the base assembly to the push rack on each side of the slip sheet assembly (dimensions A & B). If the unit is out of square in excess of 1/8″, the unit must be readjusted. To adjust, loosen the bolts on the push-pull cylinder rod ends. Grip the cylinder rod on the knurled area and rotate the rod.

NOTE It is not necessary to remove the cylinder pin, as adjustments can be made with the cylinders attached. In the event the cylinder is removed, the rod end must be in the down position when the cylinder is reassembled. (See Illustration 9-3).

(Refer to Illustration 9-2) Correct alignment and extension of the linkage mechanism and push rack are vital to effective, safe operation

© Crown 1978 PF-3466-1

M9.0 - 12 - 001

Printed in U.S.A.

M9.0 - 12 - 001

MAINTENANCE 3. Disconnect the hoses attached to the side shift cylinder. After capping the hoses and cylinder ports, remove the side shift cylinder from the unit.

4. Attach a hook or sling around the torque bar.

CAUTION

Extreme care should be taken when positioning the hook or sling so as not to catch any of the hoses which lie in the torque bar area. Also make sure the hoisting device has a capacity in excess of 1000 lb. [450 kg].

5. Unfasten the bolt which secures the keeper to the bottom of the base assembly. With a small rod or punch, drive out the pivot pin which holds the rear pusher arm in place.

6. Carefully lift the linkage mechanism straight up.

Before the slide blocks leave the guide channel, manually extend or retract the linkage to balance the load.

Once balanced, remove the unit from the base assembly.

ILLUSTRATION 9-2 When the rod is turned clockwise, the retracted length is decreased, when turned counterclockwise, the extended length is increased. After adjustment is completed, tighten the bolts on the push-pull cylinder rod ends. Cycle the push rack several times and recheck alignment.

Repeat procedure if necessary until the correct alignment is achieved.

7. Replace the worn slide blocks, making sure the grease fittings are facing down.

8. To reassemble, reverse steps 1 thru 8.

CAUTION

Never hammer on the keeper end of the pivot pin. Whenever possible, insert the pivot pin on the side opposite the keeper screw hole.

Gripper Pad When replacing the gripper pad, the following steps should be followed.

1. Extend the push rack to the far end of the platen then retract the push rack just far enough to clamp the gripper.

2. Unfasten the eight bolts which secure the gripper jaw to the push rack. Inspect all bolts and lock-washers and replace if necessary. Remove the gripper jaw.

ILLUSTRATION 9-3 COMPONENT REPLACEMENT Slide Blocks If upon regular maintenance inspection it is determined that the regulator slide blocks need replacement, the following steps should be followed to assure efficient disassembly: 1. Extend the push rack to the middle of the platen.

2. After relieving hydraulic pressure, remove and cap the hoses between the lift truck and the slip sheet assembly at the junction block located on the rear pusher arm (2 outside hoses).

© Crown 1978 PF-3466-2

M9.0 - 12 - 002

3. Relieve the hydraulic pressure and disconnect and cap the two hoses which connect the sequence valve and torque bar junction block to the push rack junction block.

4. Unfasten the eight (8) screws which attach the gripper pad and remove pad.

5. Install new pad and tighten mounting bolts to a torque of 8 to 9 ft./lbs.

6. Replace gripper jaw and tighten mounting bolts to a torque of 30 to 40 ft./lbs.

7. Reattach the hydraulic lines as mentioned in step 3 and retract the push rack to the home position.

Printed in U.S.A.

M9.0 - 12 - 002

MAINTENANCE

ILLUSTRATION 9-4 DISASSEMBLY OF THE SLIP SHEET ASSEMBLY NOTE The disassembly of the slip sheet mechanism requires a large area in which disassembled components can be placed.

Push Rack Removal Extend the push rack out to the end of the platen. After relieving the pressure from the hydraulic system, disconnect and remove the two hoses which connect the sequence valve and the torque bar junction block to the junction block located on the push rack. Cap the ends of the hoses, fittings and junction blocks. With the use of a chain hoist or overhead crane having a capacity in excess of 1000 lbs. (450 kg), attach a sling or jump chain around the upper central member of the push rack.

Unfasten and remove the two front regulator arm brackets from the push rack channel. The keepers and pivot pins located on the lower front push arm can now be removed by driving them from the inside, through to the sides of the push arms.

© Crown 1978 PF-3466-3

M9.0 - 12 - 003

NOTE When disassembling and assembling pivot pins, the pins should slide freely if the slip sheet assembly is in proper alignment. If necessary, drive lightly on the tapered end of the pins, never on the keeper end, as keeper slot damage is possible.

Raise the chain hoist and place the push rack face down on a pallet, workbench or any other suitable working surface. Return to the slip sheet assembly and disconnect and cap the remaining hoses and fittings. At this time we would recommend the numbering of all hoses to correspond to their relative connection points.

Push-Pull Cylinder Removal Once the push rack has been removed, the next slip sheet components to be disassembled are the pushpull cylinders. After supporting the cylinders to prevent falling, remove the keepers and pivot pins from the rod ends of the cylinders. Carefully lower the cylinders to the platen, making sure the cylinder rods

Printed in U.S.A.

M9.0 - 12 - 003

MAINTENANCE do not get scratched or damaged in the process.

Disassemble the remaining keepers and pivot pins from the lower cap end of the cylinders and remove the cylinders from the truck.

Linkage Mechanism Disassembly To disassemble the linkage mechanism, the front push arms must be removed before the front regulator arm.

CAUTION

A chain hoist must be attached around the torque bar to prevent the rear push arm from dropping during disassembly or personal injury or equipment damage could result.

After supporting the front push arms, remove the keepers and pivot pins, at the top of the arms, from the torque bar. These pins should be marked so they can be returned to their respective bores. Remove the arms through the center of the unit and set away from the working area. Next, unfasten the set screws from the pivot pins at the lower end of the front regulator arm, then remove the pivot pins. These pins should also be marked so they will be reinstalled in their respective bores.

Remove the regulator arm from the unit and set aside.

The rear regulator arm and rear push arm should be disassembled next. Unfasten the keepers and remove and mark the pivot pins from the center of the rear regulator and push arms. Manually lift the rear regulator arm along with its slide blocks out the back base channels and set aside. Lower the chain hoist (or overhead crane) until the rear pusher arm contacts the platen before removing the keeper and the long pivot pin.

Remove the keeper and pivot pin which extends across the bottom of the base assembly and remove the pusher arm and torque bar from the unit.

Gripper Disassembly To obtain proper access to components and fasteners, the push rack should be faced down on a pallet, workbench or any other suitable working surface. Begin by unfastening the eight (8) gripper jaw bolts and removing the jaw. Disconnect the chain links which connect the gripper bar to the three (3) clamp cylinders and remove the gripper bar. Unscrew the nuts located on the cap end of the clamp cylinders after the locking roll pins have been removed. Remove the cylinders. Unfasten the eight (8) gripper screws and disassemble gripper.

Part Replacement Inspect all components and replace as necessary.

Special attention should be taken on all bearings, slides as well as the gripper and gripper bar. Crown recommends that rather then try to straighten a bent gripper bar, the bar should be replaced.

REASSEMBLY OF THE SLIP SHEET ASSEMBLY To reassemble, reverse the disassembly procedures noting that the gripper pad bolts are to be tightened to a torque of between 8 and 9 ft./lb. and the eight gripper jaw bolts are to be tightened to a torque of between 30 and 40 ft./lb. When tightening the clamp cylinder anchor nuts, they should be backed off 1⁄2 turn from its tight position.

NOTE The rear pusher arm which includes the torque arm should be carefully removed to avoid damage to the sequence valve, junction block and fittings. After checking to see that the weight of the pusher arm is supported and balanced, proceed with disassembly.

© Crown 1978 PF-3466-4

M9.0 - 12 - 004

Printed in U.S.A.

M9.0 - 12 - 004

MAINTENANCE

ILLUSTRATION 9-5 SEQUENCE VALVE

NOTE

The sequence valve located on your slip sheet assembly is used to operate the clamp cylinders and the push-pull cylinders in proper succession. Normal break-in of a new unit, worn slip sheet linkage components or worn valve components may require valve servicing and adjusting.

However, unless there is a clear malfunction, such as the gripper failing to sequence properly, the valve is best left alone. (Refer to the Slip Sheet Assembly “Trouble Shooting Chart” for additional malfunctions.) When servicing or adjusting of the valve is needed, it can be performed without disassembling the entire unit. The linkage assembly should be extended so that the valve is in a vertical position for accessibility.

CAUTION

Before proceeding with the valve servicing, relieve the hydraulic pressure from the system.

(Refer to Illustration 9-5) The three critical valve components are the ball, the seat and the plunger. If any of these parts show signs of wear, Crown recommends that they be replaced. Begin disassembly by unscrewing the cap and removing the spring and spacers (if present). Next, remove the plunger and the ball.

© Crown 1978 PF-3466-5

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The use of a magnet will facilitate ball removal from the top port. Never use a screw-driver or other similar tool.

Carefully check the valve components as they are removed. If any of the components show wear or are damaged, they should be replaced. All parts should be thoroughly washed in clean solvent before reinstalling them in the sequence valve.

Adjustments are made by adding or removing spacers from between the spring and the plunger. Crown recommends the initial installation of two spacers.

NOTE The spacers are available in two thicknesses (.020″ [twenty thousandths] and .040″ [forty thousandths]) so a finer range of adjustments can be accomplished.

After spacer installation, a test operation of the valve will indicate whether more or less spacers are required.

When the test operations are determined to be satisfactory, the truck can be put back into production.

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MAINTENANCE SLIP SHEET TROUBLE SHOOTING CHART SYMPTOM

PROBABLE CAUSE

Push Rack Push rack not extending or retracting evenly.

a. Push cylinder’s piston “O” ring worn or cut. Replace “O” ring and backup ring. b. Air trapped in push cylinder. Bleed air system at cylinders. c. Push cylinder out of adjustment. Adjust stroke at rod end of push cylinder. d. Damaged parts of the linkage assembly. Straighten or replace parts.

Push rack is dragging on the platens.

a. Truck carriage tilted too far forward. Tilt mast back. b. Lower gripper jaw bent or damaged. Replace jaw. c. Worn slide blocks. Replace as needed. d. Damaged parts of the linkage assembly. Straighten or replace parts. e. Channels of base assembly bent. Straighten channels.

Lack of power in pushing and pulling.

a. Defective piston seals in push cylinders. Replace seals. b. Scored push cylinder tube. Replace tube. c. Scored piston seal groove in push cylinder. Replace piston. d. Load is over the rated capacity of unit. Reduce load.

Side-Shift Unit will not sideshift.

a. Defective piston seal in side-shift cylinder. Replace seal. b. Scored side-shift cylinder tube. Replace tube. c. Scored piston seal groove in side-shift cylinder.

Replace piston. d. Load is over the rated capacity of unit. Reduce load. e. Wear plates dry. Lubricate.

© Crown 1978 PF-3466-6

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MAINTENANCE SYMPTOM

PROBABLE CAUSE

Gripper Bar Gripper Bar not holding slip sheet evenly, or is tearing slip sheet.

a. Torn or wet slip sheets. Replace with good ones. b. Operator opening control valve too fast, or holding it open. (Tears sheets.) Handle control valve smoothly, evenly; do not hold it open. c. Bent or damaged gripper bar. Replace bar. (Replace grip pad if worn). d. Gripper cylinder seals on gland or piston worn out.

Replace seals. e. Scored gripper cylinder tube. Replace tube. f. Scored piston seal groove in gripper cylinder.

Replace piston. g. Load is over the rated capacity of unit. Reduce load.

Gripper Bar not operating in proper sequence.

a. Sequence valve spring weak or broken. Replace if broken. If weak, add spacers.

Gripper bar does not open immediately as push rack starts forward.

a. Not enough spring pressure in the sequence valve.

Add spacers to the spring assembly in the pushopen portion of sequence valve.

Gripper bar does not close when push rack starts to retract.

a. Not enough spring pressure in the sequence valve.

Add spacers to the spring assembly and the pull-grip portion of valve. Add more spacers if necessary.

Excessive chatter in push rack, either in the pushing or pulling direction.

a. Improper ball seating in the sequence valve.

Recheck ball seating for burrs or contamination, either on ball or seating areas, and both the pushopen and the pull-grip of the valve. b. Low in oil. Add oil.

Cylinders Oil leakage around rod.

a. Defective rod seal. Replace seal. b. Scored cylinder rod. Replace rod. c. Scored rod seal groove. Replace gland.

Oil leakage around gland.

a. Defective gland static seal. Replace seal. b. Scored cylinder tube. Replace tube. c. Scored gland static seal groove. Replace gland.

Broken rod on side-shift cylinder.

a. Side-shift cylinder anchor bracket on the carriage not aligned correctly. Replace rod and realign sideshift cylinder anchor bracket. b. Nuts on cylinder too tight. Back nuts off 1⁄4 to 1⁄2 turn.

Repeatedly scored cylinder tube, rod, gland or piston.

a. Dirty hydraulic oil. Change oil. Change oil filters, screens on truck. Replace seals and rod wiper. b. Misaligned cylinder mounts. Realign mounts.

© Crown 1978 PF-3466-7

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MAINTENANCE SYMPTOM

PROBABLE CAUSE

Other Squealing of the hydraulic system.

a. Excessive pressure in the sequence valve. Remove internal spring assembly and reduce thickness of spacers.

Broken or bent rods on push cylinders.

a. Push stroke is excessive. Cylinder rod contacts main torque bar or cylinder shell contacts cross pin in front push arm. Shorten cylinder stroke by threading rod into rod end – be sure that both cylinders extend in unison.

Attachment is loose or floppy on the lift truck carriage.

a Bronze slides are worn or missing. Replace slides.

© Crown 1978 PF-3466-8

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MAINTENANCE CYLINDER - REPAIR The purpose of this information is to aid in the repair of the lift cylinder. Many repairs to the cylinder can be made with the cylinder remaining in the truck. In order to safely and effectively perform repairs to the cylinder, the fork carriage or platform and masts must be blocked in a slightly raised position to allow for removal of chains, roller bar, yokes, caps etc. Hard wood blocks should be used to block the fork carriage and each mast assembly. 4 x 4’s (100 x 100mm) of the appropriate length is recommended. The fork carriage or platform may be approximately 36” (915mm) from the floor, the third stage (TT only) approximately 24” (610mm), the second stage approximately 12" (300mm), etc. The blocks should be positioned carefully under each side of the masts and carriage before any repairs are attempted. This procedure allows for lift chains to be disconnected and roller bar or yokes to be safely removed.

The safety shield, etc. will need to be removed when working on “Walkie” type trucks in order to remove related cylinder parts safely and efficiently. Be sure the truck’s brake is applied or all wheels chocked to prevent any truck movement during repairs.

Located in the bottom of some main lift cylinders is a velocity fuse. This device monitors oil flow. Should a break occur in a hydraulic line the cylinder would be locked in position until repairs are made. Refer to Illustration 8.1-1 for component parts and relative position.

blow dry with compressed air. Carefully inspect the ram assembly and cylinder bore. Replace if scored, grooved, pitted or worn. Minor damage to the cylinder bore can be removed with the use of a cylindrical honing tool. Place washed components in a clean container until reassembly. Whenever new packings are required, new wiper rings should also be installed.

Lift Cylinder The material covered in this section applies to all TL, TF and TT lift cylinders.

Inspection Before disconnecting battery and initial cylinder repair, a careful inspection should be made of the cylinder assembly throughout a complete lift and lower sequence.

Check roller bar or yoke area for signs of abnormal wear, damage, etc. Check ram(s) for any signs of nicks, scratches, surface imperfections, etc., that allow abnormal leakage, improper cylinder operation, or create seal damage. Check wiper ring(s) and complete cap area for component wear and/or leakage that is abnormal.

As the cylinder assembly is repaired be aware of component part condition and not only replace a worn or damaged part, but correct or replace a part that may be causing other premature wear.

Disassembly On earlier model cylinders, using a wire retaining ring as shown in Illustration 8.1-2, carefully rotate the cap to back end “A” of the retainer out of the cylinder slot. Once end “B” is exposed, pull the retainer from the positioning hole in the cap and remove. On later model cylinders, simply turn the cap counterclockwise and unscrew it from the cylinder tube. Refer to Illustration 8.1-3. Remove the cap and carefully extract the ram assembly from the cylinder bore, never allowing the ram to come in contact with any sharp edges.

ILLUSTRATION 8.1-1 Great care and cleanliness should be exercised in the disassembly and assembly of any hydraulic cylinders.

Wipe all surfaces clean of dirt and oil before attempting disassembly. Care should be taken when removing the ram from the cylinder to prevent damage to the packing on the piston end. After cylinder components are disassembled and seals, “O” rings and wipers are removed, thoroughly wash all metalic parts in solvent and

ILLUSTRATION 8.1-2 Printed in U.S.A.*

Crown PF-721 7-1 Rev. 4/88

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MAINTENANCE After attaching the screw to the screwdriver, grind off excess weld to a diameter of 5/32” (4mm). Wrap the shank with electrical tape from the tip of the screw to the screwdriver handle. This will prevent scratching of the cylinder bore or the ram.

ILLUSTRATION 8.1-4

ILLUSTRATION 8.1-3 Seals The seals used in the cylinders are made of an extremely durable, hard polyurethane material which can be deformed temporarily to allow for installation without permanent damage.

Insert the tools between the ram and the cylinder walls, 180° apart, and screw into the face of the packing (See Illustration 8.1-5). After the threads are sufficiently secured into the packing, evenly pull on the screwdriver handles until the packing is removed.

Any time a new seal is installed, packing tools are available from Crown to allow proper installation. Contact your Crown Dealer or refer to Technical Service Bulletin No. 155 for additional information. Remove any and all sharp edges, burrs and/or nicks that may be present on rams etc., that may damage a new seal during installation. Do not attempt to install a seal overexposed threads, shoulders, or any sharp surface, as permanent seal damage may result.

Seal Removal When an excessive amount of hydraulic oil is evident on the top of the cylinder (or bottom in the case of the middle cylinder on “TF” and “TT” cylinder clusters), where the ram exits from the cap, the rod packing is probably bad and should be replaced. The replacement of the packing can be accomplished without removing the ram assembly from the cylinder tube.

Unfasten and remove the cap as explained in “Disassembly”, found elsewhere in this section. If the packing is seated in the cap itself, a hooked tool should be used to remove the packing. If the packing is located below the cap and remains in the cylinder bore after the cap is removed, a pair of special tools can be used to facilitate packing removal (See Illustration 8.1-4). To make these tools, weld or braze a headless No. 8 metal screw to (4mm self-tapping) the end of a screwdriver. The screwdriver must have at least 6" (152mm) of shank length with no larger than 5/32” (4mm) shank diameter.

ILLUSTRATION 8.1-5 NOTE Extreme care should be taken to prevent damage to cylinder wall and ram assembly.

At this time, the wiper ring should also be removed since packings and wiper rings should always be replaced in pairs. Thoroughly clean the area where the seals seat.

Any burrs, dirt or seal debris must be removed before reinstalling new seals.

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Crown PF-7217-2 Rev. 4/88

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MAINTENANCE CAUTION Close inspection of seal seating critical areas should be made before the new seal is installed (SEE ILLUSTRATION 8.1-7,8. 1-12 AND 8.1-13).

Your seal failure may not have been caused by a worn seal, but rather, by burrs, nicks and dirt located on the seal seating area, causing the seal to deform and lose its sealing ability.

On piston type lift cylinders it may be difficult to determine when the cylinder’s seals are worn. This is mainly due to the position of the cylinder return line which is located on the top side of the tube assembly. When leakage past the piston packing does occur, the blowby hydraulic oil is directed back to the reservoir through a return line. Conditions that may indicate the piston packing seals are bad are slower than normal lifting time or an inability to lift rated capacity loads. A good check, short of disassembling the cylinder, is to monitor the return line at the point where it enters the reservoir.

Under normal conditions, a very small trickle of oil may be observed as the cylinder begins to bottom out at the end of its stroke. If a steady flow of oil continues throughout the stroke and if an excessive amount of oil returns to the reservoir, the piston packing seals are bad and should be replaced.

Seal Installation - General Tools used to install hydraulic seals should be of soft metal or suitable plastic, free of burrs and sharp edges.

Screwdrivers and other similar tools should not be used as they may damage the sealing edges.

The area in contact with the seal should be free of burrs, sharp edges and nicks.

If necessary to force seal over sharp edges, slots or undercuts, protective devices should be used.

Light lubrication should be applied to the seal and installation groove prior to installation. The same oil as will be used later in the cylinder should be applied.

Rod U-Cup Installation A. Small U-Cup 1. Installation Tools A groove alignment plug (see Illustration 8.1-7) is needed which should be flush with groove edge. Any metal or plastic material which is smooth and lubricated may be used.

ILLUSTRATION 8.1-7 b. A soft metal or plastic pusher rod is needed.

2. Installation Procedure Squeeze U-cup together and insert end into bore first. When lower end is engaged in installation groove, release U-cup and force upper end downward using pusher rod until U-cup snaps into groove.

B. Large U-Cup 1. Installation Tool

ILLUSTRATION 8.1-6

An installation tool made of any soft metal or hard plastic machined smooth and free of burrs with a fixed steel pin (pin 1) and two movable pins (pins 2 & 3) is required for this installation method. (See Illustration 8.1- 8).

CAUTION When replacing piston packing seals, care should be taken to make sure the new packings are positioned in the proper manner. (See IlIustration 8.1-6).

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MAINTENANCE

ILLUSTRATION 8.1-11 Cylinder U-Cup Installation ILLUSTRATION 8.1-8 2. Installation Procedure

For “lip first” installation, a sleeve similar to that shown in Illustration 8.1-12 should be used to protect the seal f r o m damage on threads and shoulders.

a. Slip the U-cup over the fixed pin (see Illustration 8.1-8, pin 1) and bend it over pin 2 as shown. b. Continue bending U-cup until pin 3 can be pushed through the U-cup loop which locks U-cup in position. c. Insert installation tool with mounted U-cup into cylinder bore until aligned with U-cup installation groove (See Illustration 8.1-9).

ILLUSTRATION 8.1-12 Piston U-Cup Installation ILLUSTRATION 8.1-9 d. Withdraw pin 3 so that U- CUP loop snaps into installation groove (Illustration 8.1-10).

The installation device described below can be used for all U-cups with a cross-section to outer diameter ratio equal to or greater than 1:8. For seals with a smaller ratio, use split designs.

Installation tool: The installation tool consists of a circular pivot with an arm inserted through it. The circular pivot is sized so as to fit in the piston guide hole. The installation tool may be made of steel.

Cone-shaped installation tools should not be used to install snap-in type piston seals as this will cause the seal to be stretched to a much larger diameter which will require very high assembly force.

ILLUSTRATION 8.1-10 e. Withdraw pin 2 and U-cup will completely snap into installation groove (Illustration 8.1-1 1).

Installation will be facilitated if piston can be clamped to vise during U-cup installation. Lubrication of seal for this type of installation is mandatory.

f. Withdraw installation tool.

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MAINTENANCE

ILLUSTRATION 8.1-13 ILLUSTRATION 8.1-16

ILLUSTRATION 8.1-14 Snap one side of the U-cup into the installation groove in piston (Illustration 8.1-13). Hold U-cup in installation groove with thumb while inserting tool (Illustration 8.1-14) in guide hole. Apply a downward force on installation tool while rotating handle 360° (Illustrations 8.1-15, 8.1-16 & 8.1-17). This will snap U-cup into groove (Illustration 8.1-18).

ILLUSTRATION 8.1-17

ILLUSTRATION 8.1-18

ILLUSTRATION 8.1-15

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MAINTENANCE Cylinder Assembly After packings and seals are in place and the ram assembly has been installed, reattach the cap. On earlier model trucks, align the hole in the cap with the slot in the cylinder wall and carefully press the cap into position.

CAUTION Care should be taken when inserting the cylinder cap, to prevent threads and sharp edges from damaging new seals and packings.

ILLUSTRATION 8.1-3 Once the cap is in place and the cap hole is visible through the cylinder slot, insert the hooked end of the wire retaining ring into the cap hole. Turn the hex head area of the cap until the tapered end of the retainer is flush with the cylinder tube. Refer to Illustration 8.1-2.

ILLUSTRATION 8.1-2

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On later model trucks, apply thread locking adhesive (61004-14) to cap threads. Screw cap clockwise until tight and flush with the top of the cylinder tube. Refer to Illustration 8.1-3.

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MAINTENANCE CYLINDERS – GENERAL

SEALS

The material covered in this section applies to the SSR lift and tilt cylinders. Great care and cleanliness should be exercised in the disassembly and assembly of any hydraulic cylinders. Wipe all surfaces clean of dirt and oil before attempting disassembly. Care should be taken when removing the piston from the cylinder to prevent damage to the packing on the piston end. After cylinder components are disassembled and seals, “O” rings and wipers are removed, thoroughly wash all metalic parts in solvent and blow dry with compressed air. Carefully inspect the ram assembly and cylinder bore. Replace if scored, grooved, pitted or worn. Minor damage to the cylinder bore can be removed with the use of a cylindrical honing tool. Place washed components in a clean container until reassembly. Whenever new packings are required, new wiper rings should also be installed.

The seals used in the cylinders are made of an extremely durable, hard polyurethane material which can be deformed temporarily to allow for installation without permanent damage.

SEAL REMOVAL Tilt Cylinder When an excessive amount of hydraulic oil is evident at the rod end of the tilt cylinder, where the rod exits from the cylinder cap, the U-cup seal or wiper ring is probably bad and should be replaced. If the area mentioned above is oil-free but oil is present around the outside of the cap and the cylinder tube, the “O” ring or the back-up ring is probably bad and should be replaced.

To replace seals, remove the cap as explained in “Disassembly” found elsewhere in this section. With the use of a hooked tool, carefully extract the seal from its seat. Thoroughly clean the area of any burrs, dirt or seal debris.

CAUTION

Close inspection of the seal seating critical area should be made before the new seal is installed (See Illustration 8-3). Your seal failure may not have been caused by a worn seal, but rather by burrs, nicks and dirt located on the seal seating area causing the seal to deform and lose its sealing ability.

NOTE Always replace seal in pairs. (Example: If the Ucup is worn and must be replaced, also replace the wiper ring.) If there is any doubt about the exact origin of the leakage, Crown recommends the replacement of all cap seals.

ILLUSTRATION 8-1 DISASSEMBLY On the tilt cylinders, using a wire retaining ring as shown in Illustration 8-1, carefully rotate the cap to back end “A” of the retainer out of the cylinder slot. Once end “B” is exposed, pull the retainer from the positioning hole in the cap and remove. On the lift cylinder, simply turn the cap counterclockwise and unscrew it from the cylinder tube.

Remove the cap and carefully extract the piston assembly from the cylinder bore, never allowing the ram to come in contact with any sharp edges.

© Crown 1978 PF-3462-1

M8.0 - 12 - 001

If one of the tilt cylinders appears to extend or retract slower than the other tilt cylinder, it could mean that the piston quad ring or piston back-up rings are bad and should be replaced. Use the seal removal procedure mentioned earlier in this section.

Lift Cylinder On lift cylinders it may be difficult to determine when the cylinders’ seals are worn. This is mainly due to the position of the cylinder return line which is located on the top side of the tube assembly. When leakage past the piston packing (Chevron Pak) does occur, the blow-by hydraulic oil is directed back to the reservoir through a return line. Conditions that

Printed in U.S.A.

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MAINTENANCE may indicate the piston packing seals are bad are slower than normal lifting time or an inability to lift rated capacity loads. A good check, short of disassembling the cylinder, is to monitor the return line at the point where it enters the reservoir. Under normal conditions, a very small trickle of oil may be observed as the cylinder begins to bottom out at the end of its stroke. If a steady flow of oil continues throughout the stroke and if an excessive amount of oil returns to the reservoir, the piston packing seals are bad and should be replaced.

Rod U-Cup Installation A. Small U-Cup 1. Installation Tools a. A groove alignment plug (see Illustration 8-3) is needed which should be flush with groove edge. Any metal or plastic material which is smooth and lubricated may be used.

ILLUSTRATION 8-3 b. A soft metal or plastic pusher rod is needed.

2. Installation Procedure

ILLUSTRATION 8-2

CAUTION

When replacing piston packing seals, care should be taken to make sure the new packings are positioned in the proper manner. (See Illustration 8-2).

As is the case with tilt cylinders, any oil leakage around the cap area of the lift cylinder indicates bad seals which should be replaced. Refer to “Seal Removal – Tilt Cylinder” for seal removal procedures.

Squeeze U-cup together and insert end into bore first. When lower end is engaged in installation groove, release U-cup and force upper end downward using pusher rod until U-cup snaps into groove.

B. Large U-Cup 1. Installation Tool An installation tool made of any soft metal or hard plastic machined smooth and free of burrs with a fixed steel pin (pin 1) and two movable pins (pins 2 & 3) is required for this installation method. (See Illustration 8-4).

SEAL INSTALLATION Tools used to install hydraulic seals should be of soft metal or suitable plastic, free of burrs and sharp edges.

Screwdrivers and other similar tools should not be used as they may damage the sealing edges.

The area in contact with the seal should be free of burrs, sharp edges and nicks.

If necessary to force seal over sharp edges, slots or undercuts, protective devices should be used.

Light lubrication should be applied to the seal and installation groove prior to installation. The same oil as will be used later in the cylinder should be applied.

© Crown 1978 PF-3462-2

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ILLUSTRATION 8-4

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MAINTENANCE 2. Installation Procedure a. Slip the U-cup over the fixed pin (see Illustration 8-4, pin 1) and bend it over pin 2 as shown. b. Continue bending U-cup until pin 3 can be pushed through the U-cup loop which locks Ucup in position. c. Insert installation tool with mounted U-cup into cylinder bore until aligned with U-cup installation groove (See Illustration 8-5).

CYLINDER ASSEMBLY After packings and seals are in place and the ram assembly has been installed, reattach the cap. On tilt cylinders, align the hole in the cap with the slot in the cylinder wall and carefully press the cap into position.

CAUTION

Care should be taken when inserting the cylinder cap, to prevent threads and sharp edges from damaging new seals and packings.

Once the cap is in place and the cap hole is visible through the cylinder slot, insert the hooked end of the wire retaining ring into the cap hole. Turn the hex head area of the cap until the tapered end of the retainer is flush with the cylinder tube. On the lift cylinder, screw the cap clockwise until the cap is tight and flush with the top of the cylinder tube.

CYLINDER — SUMMARY

ILLUSTRATION 8-5 d. Withdraw pin 3 so that U-cup loop snaps into installation groove (Illustration 8-6).

Occasionally, a slight creep of the fork assembly may occur. This may be due to internal leakage in the piston pak, but it can also be caused by leakage in the solenoid or check valve. To seat these valves properly when this occurs, raise and lower the forks to flush out any foreign material from the valve seat.

A thorough check of the system for leaks should be conducted if abnormal oil losses occur. The hydraulic system is designed to eliminate mechanical damage even if fittings become loose.

TILT CYLINDER ADJUSTMENT

ILLUSTRATION 8-6 e. Withdraw pin 2 and U-cup will completely snap into installation groove (Illustration 8-7).

Before adjusting the tilt cylinders, check to see that the platen heel height is properly adjusted (5-7/8″ [129 mm]).

If this measurement is correct, loosen the set screws which lock the tilt cylinder rods to the rod end bearings.

With the tilt cylinders fully extended, adjust (turn) the tilt cylinder rods to a position where the tips of the platen rest on the floor.

NOTE Clockwise rotation of the rod will lower the platen tip while counterclockwise rotation will raise the tip.

Once the adjustments are completed, retighten the set screws. At this time, cycle the tilt cylinders and check to see that both cylinders are bottoming simultaneously. If they do not, readjust the rod end bearing.

ILLUSTRATION 8-7 f. Withdraw installation tool.

© Crown 1978 PF-3462-3

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Printed in U.S.A.

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MAINTENANCE To better understand the SCR control system used in this unit it is necessary to know what an SCR is, how it is used to control the drive motor speed, and all other travel functions.

WHAT IS AN SCR? The Silicon Controlled Rectifier (SCR) is a semiconductor rectifier that can be used as a switch; it may assume either a conducting or non-conducting state (On or Off).

The SCR System – The SCR is placed between the battery and drive motor where it is switched on and off providing pulses to the motor. Motor speed is determined by the average voltage applied across the motor determined by the average of the on-off times seen by the motor. Low speed is obtained with the potentiometer providing maximum ohms to the oscillator section of the control card.

To better understand how the system works, refer to the enclosed diagram and follow the circuit operation as follows.

CIRCUIT OPERATION (See Illustration 3) The control circuit is energized by closing the key switch, brake switch and placing the direction and speed controller in the operating position. This applies power to the control card turning on the PMT drive, which will close the selected directional contactor, completing the circuits to the drive motor.

The control card then supplies a gate pulse to 2 REC turning it on to a conducting state, allowing current to flow from the battery through 1C, 2 REC, 1X, T1-T2, motor field, motor armature, sensor, and back to the battery. After 1C charges, 2 REC shuts off, due to lack of holding current, the control card then checks that 1C is charged.

SCHEMATIC

ILLUSTRATION 1 Its operation is like a diode in that it will allow current to flow in one direction only, blocking current in the other direction. This is where the similarity ends; the SCR when connected to a power source will not conduct until a turn-on signal is supplied to the gate. Once turned on, the SCR will conduct even with no signal on the gate, until the current flow through the SCR is reduced to zero, either by removing all power or by supplying a reverse voltage momentarily between the cathode and anode.

The control card then supplies a gate pulse to 1 REC turning it on to a conducting state, allowing current to flow from the battery through 1 REC, T1-T2, motor field, motor armature, sensor, and back to the battery. 5 REC turns on and allows current to flow T4-T3, 1C, 1 REC, 5 REC back to T4-T3. This current charges 1C positive (card term. 7 is now positive). This voltage is now stored on the capacitor until it is time to turn off 1 REC. This charging cycle occurs in less than 1 milli-second (.001 seconds) and 5 REC shuts off.

Current continues to flow in 1 REC until the control card turns on 2 REC. When 2 REC conducts, capacitor 1C discharges around the circuit composed of 1C, 1 REC, 2 REC and 1X. This discharge current opposes the battery current through 1 REC so that the resultant current is zero. With reverse voltage across 1 REC, 1 REC is turned off. Current continues to flow in the 2 REC, 1C and battery loop until the capacitor (card term. 7) is fully charged negative. This charge exceeds battery voltage by an amount which is a function of motor current, and 2 REC turns off. Illustration 4 shows the pulsing of current from the battery.

A0022

ILLUSTRATION 2

Crown 1979 PF-5030-1 Rev. 5/87

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MAINTENANCE

ELEMENTARY WIRING SCHEMATIC ILLUSTRATION 3

Crown 1979 PF-5030-2 Rev. 5/87

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MAINTENANCE During the off time, the energy stored in the motor, by virtue of its inductance, will cause current to circulate through the motor around the loop formed by 3 REC. Thus providing what is called “flyback current”.

Illustration 5 shows the nature of the motor current which is composed of both battery current and the inductive flyback current. It should be noted that the average motor current measured will be greater than the average battery current. The SCR control, in effect, converts battery current at battery volts into a higher motor current and lower motor volts.

CONTROL FEATURES Oscillator — The oscillator section of the card has two adjustable features and one fixed feature. With the accelerator potentiometer at maximum ohms, the creep speed can be adjusted with a trimpot on the card. Top speed is fixed by card design, and is obtained with the accelerator potentiometer at minimum ohms. The control will provide 85-95 percent of available voltage in the SCR mode.

Illustration 6 shows the oscillator frequency curve.

The time for the next cycle to start is determined by the time that the control card takes to oscillate. This frequency of oscillation is controlled by the potentiometer in the accelerator and automatic circuitry in the card. Slow speed is obtained by having maximum ohms in the potentiometer. As the resistance in the potentiometer decreases, the speed of the motor increases. With level operation, the SCR circuit is capable of delivering approximately 85 to 90 percent speed. For full speed operation, the 1A contactor is closed to apply full battery voltage across the motor.

A0017

Oscillator Freqency Curve ILLUSTRATION 6 With the accelerator potentiometer at maximum ohms, the creep speed can be adjusted with a trimpot on the card. Top speed is fixed by card design, and is obtained with the accelerator potentiometer at minimum ohms.

A001

Battery Current ILLUSTRATION 4

The rate at which the oscillator may increase its % ON time is limited by “Controlled Acceleration”. The minimum time required to go from creep speed to the 1A pickup point may be varied by an indexed trimpot (C/A) on the card, adjustable from approximately 0.5 seconds to 1.0 seconds.

The % ON time has a range of approximately 5 to 95 percent. The center operating condition of the oscillator is at 50 percent ON time with a nominal 1.7 milliseconds ON time and 1.7 millisecond OFF time. This corresponds to a maximum operating frequency of about 300 hertz. At creep the ON time will decrease to approximately 0.8 milliseconds while OFF time will become in the order of 20 milliseconds. At full SCR operation, this condition will be reversed (short OFF time, long ON time). This variation of ON and OFF time of the oscillator produces the optimum frequencies through the SCR range. See Illustration 6.

A001

Motor Current ILLUSTRATION 5 Crown 1979 PF-5030-3 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 003

M4.2 - EV1 - 003

MAINTENANCE Current Limit This circuit monitors motor current by utilizing a sensor in series with the armature. The information detected across the sensor is fed back to the card so current may be limited to a preset value. If heavy load currents are detected, this circuit overrides the oscillator and limits the average current to a value set by the C/L adjustment pot.

The C/L setting is based on the maximum thermal rating of 1 REC and the peak voltage on the capacitor. Because of the flyback current through 3 REC, the motor current usually runs 2 to 3 times the battery current limit value.

The current limit is set with the (C/L) trimpot.

Plugging Slowdown is accomplished when reversing by providing a small amount of retarding torque for deceleration. If the vehicle is moving and the directional control is moved from forward to reverse, the motor field is reversed.

During the 1 REC off times the motor armature, driven by the inertia of the vehicle, acts as a generator. This generated current passes through 4 REC and the sensor.

The plug signal is initiated by the fact that the directional switch has moved from one direction to the other. The oscillator section assumes a plug current limit mode and regulates the armature current to obtain the desired braking torque. During the plugging mode the control oscillates at about 10 HZ resulting in a smooth plug. The distance of stopping can be set with the (plug) trimpot.

Ramp Start This non-adjustable feature provides full SCR torque to restart a vehicle on an incline. The memory for this function is the directional switch. When stopping on an incline, the directional switch must be left in its original or off position to allow the control to assure full power when restarted.

Full Power Transition This built-in feature provides smooth transition from SCR to 1A bypass. This is accomplished by the SCR continuing to pulse until the 1A contactor power tips close.

1A Control The 1A contactor has 6 modes of control: 1. Demand Pickup (fixed feature of the card) — If the oscillator has attained a % ON time equivalent to a motor voltage of 80 to 85 percent of the available battery volts, the 1A contactor will automatically pick up.

The 1A switch in the accelerator is not necessary for this function. On “H3” cards, this feature may be eliminated by adding a jumper from R9 to R4.

2. Timed Pickup — This feature works with the 1A switch in the accelerator. The time-delay pickup of 1A is provided by a circuit in the card. This feature allows 1A to be picked up after a time delay without reaching the demand point, and is normally used to apply full power at near stall conditions. This time delay is adjustable by means of a 1A time trimpot on the card.

3. Thermal Holdoff — This feature prevents the 1A contactor from closing as a function of time with the truck in severe thermal cutback to avoid torque jumps.

When a truck starts to go into thermal cutback, the 1A time will gradually increase to infinity as the control goes deeper into thermal cutback. On “E” and later cards, this feature may be eliminated by adding a jumper from R2 to R4.

4. Current Holdoff — This is accomplished by not wiring in the 1A switch in the accelerator, otherwise 1A will close at stall after the 1A time delay. If the percentage on is reduced below 80%, the 1A timer is shut off and 1A will not operate until the vehicle can accelerate to a point where the demand pickup will automatically close the 1A contactor.

5. 1A Plugging Holdoff — This built-in feature is designed to prevent 1A closure anytime during plugging.

6. 1A Dropout (1ADO) — This adjustable feature can be set to open the 1A contactor if the traction motor is subjected to excessive currents. The dropout is adjustable with the (1A DO) trimpot. Opening the start switch or depressing the brake, or returning the directional switch to neutral will unlock the dropout circuit and allow 1A to pick up on demand or time as mentioned above.

Pulse Monitor Trip This function contains three features: The look ahead, the look again, and the automatic look again reset.

If 1 REC is shorted or 1A is welded, PMT will look ahead and prevent F or R from closing if either condition exists.

If 1 REC fails to commutate, or if 1A power tips remain closed when they should be open, the control will open F or R contactor. PMT will then look again by testing for a fault and, if none, reclose F or R. If the fault still exists, the F or R will reopen and remain open.

If 1A closes before a second commutation failure, the look again counter will automatically reset. This eliminates the inconvenience of resetting the PMT with the key switch if the tripping is due to random noise.

Crown 1979 PF-5030-4 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - RV1 - 004

M4.2 - EV1 - 004

MAINTENANCE When the PMT circuit prevents F or R from closing, the PMT circuit can be reset only by opening the Key switch.

Static Return To Off This built-in feature of the control requires the driver to return the directional control to neutral anytime he leaves the vehicle and returns. If the seat switch or key switch is opened, the control will shut off and cannot be restarted until returned to neutral. A time delay is built into the seat switch input, .75 second, to allow momentary opening of the seat switch if a bump is encountered.

Coil Drive Modules These modules are located typically on the contactor portion of the control. They are the power devices that operate F, R and 1A contactor coils. These modules pick up or drop out these coils on command from the control card. All modules are equipped with reverse battery protection in that if the battery is connected incorrectly, none of the contactors controlled can be closed electrically.

Thermal Protector (TP)

limits, the thermal protector will lower the maximum current limit and not allow 1 REC to exceed its temperature limits. Even at a reduced current limit, the vehicle will normally be able to reach sufficient speed for full 1A operation, thereby allowing the panel to cool. As the panel cools, the thermal protector will automatically return the control to full power.

Filters Hash filters and varistors prevent damage to the control circuit that can be caused by voltage spikes (Momentary surges when circuits are made or broken) from contactors, solenoids, etc.

Low Voltage Batteries under load, particularly if undersized or more than 80 percent discharged, will produce low voltages at the SCR control terminals. The EV-1* control is designed for use down to 50 percent of the nominal battery volts.

Low battery volts may cause the control to not operate correctly but the PMT should open the F or R contactor in the event of a commutation failure.

This temperature sensitive device is mounted in the 1 REC heat sink. If the 1 REC temperature exceeds design

Oscillator Card Changes

* Only on cards up to Rev. B-2 (See card nameplate) NOTE 1 - Can replace any card, however, requires group 1 thermal protector as described in feature 2.

NOTE 2 - Can replace any card, however, requires jumper between R4 on control card and battery negative.

Crown 1979 PF-5030-5 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 005

M4.2 - EV1 - 005

MAINTENANCE Oscillator Card Change Features 1. Optional reduced current limit. Adding a connector from R1 to R2 will reduce motor current (by about 50 amperes when used with the EV-1B control).

2. Low thermal cutback. Reduction in current limit is adequate only when the panel is mounted on a good heat sink. 1A thermal holdoff occurs at a low temperature. Thermal protector (group 1) must be used with this card.

3. No PMT look again reset. The PMT look again counter will not reset when 1A closes.

4. 1 REC synch circuit. 1 REC synchronizing circuits shut off 1 REC gate pulse causing failure to gate 1 REC with certain motors.

5. Non-optional 1A thermal holdoff. The provisions for disabling 1A thermal holdoff by adding a connector from R2 to R4 is not available.

6. Optional no 1A on demand and soft ramp start.

Adding a connector from R9 to R4 softens the initial torque on ramp start in some applications, and also prevents 1A from picking up on demand.

7. Microprocessor based design. Battery negative connection to R4 required.

8. Not to be used as service replacements. Could cause malfunction on units not originally equipped with same card number.

A0023

9. Card interchangeable on all EV1 systems used on Crown trucks.

ILLUSTRATION 7

Oscillator Card Identification

AUXILIARY CARDS

Oscillator cards used on EV1 traction SCR controls are IC3645OSC type cards. The last three (3) digits are the card revision numbers. A label below the adjustment potentiometers on the outer case contains these identification numbers.

Limit Switch Cards SP Models prior to 9/84 - (ILLUSTRATION 8) The limit switch card is used to place a fixed amount of resistance in the oscillator circuit to limit the maximum speed the unit will travel in the SCR range, but can be bypassed for top speed operation when platform is lowered.

A0024

ILLUSTRATION 8

Crown 1979 PF-5030-6 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 006

M4.2 - EV1 - 006

MAINTENANCE

PC Models — (Illustration 8) The limit switch card is used to place a fixed amount of resistance in the oscillator circuit to limit the maximum speed the unit will travel in the SCR range when operated as a walkie, but can be bypassed by the high speed switch. (See component testing section for more specific resistance values.)

PE Models — (Illustration 9) The limit switch card is used to place a fixed amount of resistance in the oscillator circuit to limit the maximum speed the unit will travel in the SCR range when used as a walkie, but is bypassed by

A0026

ILLUSTRATION 10 SP Models after 9/84 - (Illustration 10) The limit switch card is used to place a variable amount of resistance in the oscillator circuit to limit the maximum speed the unit will travel in the SCR range when operated with forks elevated above 24 inches.

NOTE The following procedures refer to adjustments located on the limit switch card which is mounted in the electrical box on the platform, behind the control pod. Refer to Illustration 11 for placement of potentiometers on this card.

Adjustments should be made with no load on forks. The speed lane should be 40 feet long. Before setting creep speed, run the truck through the 40 ft. speed lane, six times, plugging at each stop. Raise the forks so that the mast limit switch is activated and run the truck through the speed lane six times, utilize plugging at each stop.

The truck is now ready for card adjustments.

NOTE Truck must have accelertion distance of at least 40 feet before entering speed check.

The Limit Switch Card adjustments, CS & LS, are single turn potentiometers. Attempting to turn more may damage the potentiometers.

A0025

ILLUSTRATION 9 the high speed switch in the cross bar. This is used in conjunction with a diode block and relay (RA) which also controls the speed away from the operator when the safety reversing switch is activated.

Turn adjustment clockwise to increase speed.

Crown 1979 PF-5030-7 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 007

M4.2 - EV1 - 007

MAINTENANCE 2. All external components having inductive coils must be filtered. Refer to Crown for specifications.

3. The control should not be steam cleaned. In dusty areas, use low pressure air to blow off the control. In oily or greasy areas, a mild solution of detergent or denatured alcohol can be used to wash off the control and then blow completely dry with low pressure air.

The control can also be cleaned with Freon TF* degreaser.

4. Terminal boards and other exposed SCR control parts should be kept free of dirt and paint which might change the effective resistance between points.

A0027

ILLUSTRATION 11 1. Set SCR CARD creep adjustment for an empty travel speed of approximately 2″ per second when the twist grip is moved enough to pull in either the forward (F) or reverse (R) contactor.

2. Raise the forks so that the mast limit switch is activated. Move twist grip to maximum speed position.

Adjust limited speed adjustment on Limit Switch Card so that an empty SP36 or SP42 travels 40′ in 10.9 to 12.15 seconds (2.5 mph). An SP48 should be adjusted to travel 40′ in 13.6 to 15.15 seconds (2.0 mph).

3. Set creep speed adjustment on Limit Switch Card for an empty travel speed of approximately 2″ per second when twist grip is moved enough to pull in either the forward (F) or reverse (R) contactor. The mast limit switch must be activated during this time.

NOTE After all adjustments have been set, seal cover with silicon rubber compount. (Crown No. 65031-2) Dual Motor Card (dual drive motor trucks only)

5. The truck should not be plugged when the truck is jacked up and the drive wheels are in a free wheeling position. This can create excessive voltages that can be harmful to the control.

Meter All voltage and resistance readings refered to in the Maintenance Instructions were taken with an analog type meter with 20,000 ohms/volt dc input impedance and ± 2% full scale accuracy, e.g. Simpson 260.

If a meter other than that specified is used, it is possible to obtain readings that do not compare with what is described. This does not mean that the component being checked is defective. For example, some digital meters are capable, when checking a diode in circuit, of reading resistance that is in parallel with the diode. When compared to the testing procedure, the diode would be considered defective, when in reality the meter is not reading the diodes but the parallel resistors resistance. Some meters also are sensitive enough to read electrical noise which may be present. In some instances a voltage reading could exceed battery volts.

In view of this, it is important to know and understand the meter that you are using, otherwise the testing procedures and troubleshooting can be confusing and misleading.

See later in EV1 section.

MAINTENANCE INSTRUCTIONS General The SCR control, like all electrical apparatus, does have some thermal losses. The semiconductor junctions have finite temperature limits above which these devices may be damaged. For these reasons, normal maintenance should guard against any action which will expose the components to excessive heat, such as steam cleaning; or which will reduce the heat dissipating ability of the control, such as restricting air flow.

The following DO’S and DON’TS should be observed: 1. Any controls that will be used in ambients of 100° F (40° C) or over should be brought to the attention of Crown.

Tune Up New or Mistuned Card. Panels are factory adjusted for a particular motor and truck and should not need adjustment. The card is supplied with single turn potentiometer adjustments and the box is marked with “dial” setting.

Turning pots C.W. increases the particular function, for example, C.W. adjustment increases creep speed, acceleration rate, current limit, 1A time, stiffness of plug, etc.

With a new card, turn all pots fully CCW to “1′, then set each pot to the setting for the particular truck as listed.

Potentiometer settings apply only to truck models listed.

Crown 1979 PF-5030-8 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 008

M4.2 - EV1 - 008

MAINTENANCE

A0028

ADJUSTMENT POTENTIOMETERS (trimpots) ILLUSTRATION 12 Use Chart 1 for 1H3 cards and Chart 2 for 5H9 cards.

SP36 SP42 SP48 PE, PC, PR, SSR RC, SC RR, RS, RD (24 Volt) RR, RS, RD (36 Volt) TR, TWR

* CREEP 81⁄2 7 71⁄2 51⁄2 7 1/2 61⁄2 41⁄2 6

* C/A 4 41⁄2 41⁄2 4 3 3 3 2

C/L 5 9 9 61⁄2 9 9 8 5

1A TIME 3 6 6 7 6 6 51⁄2 21⁄2

1ADO 21⁄2 7 7 7 31⁄4 31⁄4 31⁄4 2

* PLUG 4 41⁄2 41⁄2 6 5 6 6 4

FWPU N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A.

FWDO N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A.

* Check these adjustments to meet the specifications listed for your unit as follows and adjust as necessary.

CHART 1 SP36 SP42, SP48 PE, PC, PR, SSR RC SC RR, RS, RD (24 Volt) RR, RS, RD (36 Volt) TR, TWR

* CREEP 3 3 3 3 3 51⁄2 3 3

* C/A 2.5 3 3 11⁄2 11⁄2 11⁄2 11⁄2 2

C/L 9 9 9 9 9 9 9 9

1A TIME 21⁄2 51⁄2 6 51⁄2 51⁄2 51⁄2 5 41⁄2

1ADO 2 2 2 31⁄2 31⁄2 2 2 21⁄2

* PLUG 3 31⁄2 2 7 6 3 3 51⁄2

FWPU N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A.

FWDO N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A.

* Check these adjustments to meet the specifications listed for your unit as follows and adjust as necessary.

CHART 2 Creep Speed SP36-SP42 – Raise forks so that mast switch is activated. Move control handle to maximum speed. Adjust creep speed so empty truck moves 44 feet in 12 to 13 seconds (2.5 MPH).

SP48 – Raise forks so that mast switch is activated.

Move control handle to maximum speed. Adjust creep speed so empty truck moves 44 feet in 15 to 16 seconds (2.0 MPH).

PE-PC-TWR-TR – Turn high speed switch off if used. Move control handle to maximum speed. Adjust creep speed so empty truck moves 44 feet in 7 to 8 seconds (4 MPH).

PR-SSR-RR-RS-RD-RC-SC – Raise forks so that mast switch is activated. Move speed control just enough to

pull in either the F or R contactor. Adjust the creep speed trimpot so empty truck moves at a rate of approximately 2 inches per second.

Current Limit (C/L) Equipment required: Shunt and meter-500 AMP. Connect shunt in series with the battery and connect meter. Turn C/L fully counterclockwise. Place truck against obstacle.

Block 1A contactor tips open. Jumper brake switch. Leave brake applied and move control handle to maximum speed. Adjust C/L between; 180 to 225 amps for RC and SC, 190 to 225 amps for RR, RS, RD, SP, PE, PC, TWR, TR, PR and SSR. Motor must not turn while adjusting.

(Turn adjustment clockwise to increase current). Do not stall motor more than 30 seconds at a time and allow to cool between test. After setting remove jumper and block.

Crown 1979 PF-5030-9 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 009

M4.2 - EV1 - 009

MAINTENANCE Controlled Acceleration (C/A) Turn 1A Time adjustment fully clockwise. With forks lowered and an empty truck, move control handle rapidly to maximum speed. Adjust C/A until a smooth, jerk-free increase of speed is obtained (approximately 1 - 1 1/2 seconds to full SCR speed). Turn 1A Time adjustment fully counterclockwise.

1A Time With forks lowered and an empty truck, move control handle rapidly to maximum speed. Adjust 1A Time until a smooth, jerk-free transition from SCR speed to 1A bypass speed is experienced (approximately 1 1/2 - 2 seconds). Turning adjustment clockwise increases rate of acceleration.

1A Drop-Out Equipment required: Shunt and meter-750 AMP. Connect shunt in series with the battery and connect meter. Turn 1A drop-out fully clockwise. Place truck against obstacle.

Jumper brake switch. Release brake and move control handle to maximum speed forward or reverse (1A switch closed). (Turn adjustment clockwise to increase current at which drop-out occurs). After 1A contactor has pulled-in load motor by applying brake until “drop-out amps” is obtained.

Slowly adjust 1A drop-out till 1A contactor drops out. This adjustment is time dependent. Turning adjustment too fast will give incorrect setting.

Release brake and return control handle to neutral. Again pull in 1A contactor and load to “hold amps”. 1A contactor shall not drop out within 2 seconds. Load to “drop out amps”.

1A contactor shall drop out within 1 second. Do not stall motor more than 15 seconds at a time and allow to cool between test. After setting remove jumper.

Plug With forks lowered and with an empty truck, run truck in forward direction with 1A contactor pulled in. Move control handle rapidly to maximum reverse direction. Adjust plugging so that truck stops in 11 to 13 feet, except RR, RS and RD trucks which stop in 13 to 15 feet. Turning adjustment clockwise decreases plugging distance.

After all adjustments have been set, seal cover with silicone rubber compound (Crown No. 65031-2).

CHART 3

Crown 1979 PF-5030-10 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 010

M4.2 - EV1 - 010

MAINTENANCE TYPICAL PHYSICAL ARRANGEMENT AND IDENTIFICATION OF COMPONENTS

A0029

(1)

Main SCR (1 REC)

(10) Plugging Diode (4 REC)

(2)

Thermal Protector

(11) Turn-off SCR (2 REC)

(3)

Commutating Capacitor (1C)

(12) Charging SCR (5 REC)

(4)

Oscillator Card

(13) Power Connections

(5)

Card Adjustments

(14) Filters for 2 and 5 REC

(6)

Quick Card Release

(7)

Card Terminal Board

(15) Motor Current Sensor (Located behind middle power connector)

(8)

Card Connector

(9)

Flyback Diode (3 REC) Transformer and choke (1X) located in encapsulated block under capacitor. 3 REC filter (23 Fil) located under pigtail of the diode.

(16) 23 R Resistor

ILLUSTRATION 13 Crown 1979 PF-5030-11 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 011

M4.2 - EV1 - 011

MAINTENANCE Replacement – EV1 Components

3. Disconnect all transformer leads.

When replacing stud type semiconductors such as 2, 3, 4 and 5 REC, it is not necessary to torque these devices to a specific value. However, the device should be screwed into the heat sink and tightened to a snug fit. SCR gates, not screw connected, terminate inside card plug. Remove card connector for access to stab terminals.

4. Remove 2 REC, 5 REC and Snubbers.

5. Remove 4 mounting bolts and lift transformer free.

INSTRUCTIONS FOR REMOVAL OF CARD 1. Pry open the latches carefully with a screwdriver as shown in Illustration 14.

The use of a heat transfer grease (Crown No. 93983) is recommended.

When replacing module semiconductors such as 1 REC: 1. Remove all module connections.

2. Remove module by backing out the two screws at the device sides.

3. If a 1 REC, remove the thermal protector.

4. Clean the insulator surface with a clean rag and isopropyl alcohol.

5. Inspect insulator surface for tears or cracks. If defective, replace. Wipe a light layer of machine oil on base and smooth insulator into position.

6. Coat insulator with a light coat of heat transfer grease.

A0030

ILLUSTRATION 14 2. Discharge capacitor 1C. 3. Remove the four (4) screws shown in Illustration 15.

7. Install thermal protector in new module. Tighten until snug.

8. Set new module on insulation and start screws back into the base. Be sure to use original hardware and flat washers. Run screws in to “Finger tight”. Check to see that the bottom of the heat sink is flat against the insulator. Alternately tighten the two screws by 1⁄4 turn until firm.

9. Replace all connections removed in step 1.

CAPACITOR (EV-1A & B)

A0031

1. Remove card completely. See card removal procedure.

2. Remove card box right support.

ILLUSTRATION 15 4. Jack out the right and left-hand terminal board, using a screwdriver in the slots, (leaving the wires intact) as shown in Illustration 16.

3. Remove nuts from capacitor connections and slide capacitor away.

4. Reverse procedure to install new capacitor.

22 REC AND 25 REC When replacing these devices, use original hardware in the same holes, as the inserts are used for electrical connections to the transformer.

TRANSFORMER/CHOKE 1. Remove card box and card supports. See card removal procedure.

A0032

2. Remove capacitor.

ILLUSTRATION 16

Crown 1979 PF-5030-12 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 012

M4.2 - EV1 - 012

MAINTENANCE 5. Jack out the bottom plug with a screwdriver as shown in Illustration 17.

CAUTION

Discharge Capacitor before proceeding to prevent component damage.

The card can be removed by hinging 10 degrees and pulling out, or, if panel components (not related to card hinge mountings) are to be replaced, disregard card removal instructions above except Step 1 and the card will hinge up to 90 degrees.

Main SCR Control Card All troubleshooting is written to check all outside devices and eliminate them as the source of symptoms. The conclusion being then, that the card is faulty. See card removal sequence in replacement section.

Capacitor 1C Disconnect battery and discharge capacitor. Measure ohms through the capacitor using the R x 10,000 scale.

Meter should read zero and then swing to above 100,000 ohms. Replace capacitor if above reading is not obtained.

Contactors F, R, 1A, and P NOTE 1. Control is arranged so that F and R do not break current. Check to see that 1A drops out ahead of F or R. NOTE 2. Most contactor coils are polarity sensitive. The left-hand terminal must be connected to positive.

A0033

ILLUSTRATION 17

COMPONENT TESTING All voltage and resistance readings referred to in Component Testing were taken with an analog type meter with 20,000 ohms/volt dc input impedance and ± 2% full scale accuracy, e.g. Simpson 260.

If a meter other than that specified is used, it is possible to obtain readings that do not follow what is described. This does not mean that the component being checked is defective. For example, some digital meters are capable, when checking a diode in circuit, of reading resistance that is in parallel with the diode. When compared to the testing procedure, the diode would be considered defective, when in reality the meter is not reading the diodes but the parallel resistors resistance. These meters normally have a special diode test scale. Some meters also are sensitive enough to read electrical noise. If making a voltage check on a line with high amounts of electrical noise, a reading higher than the source voltage is possible.

In view of this, it is important to know and understand the meter that you are using. Unless you do, the testing procedures and troubleshooting can be confusing and misleading.

A0018

ILLUSTRATION 18 Potentiometer in Accelerator To check operation of the potentiometer, disconnect battery and disconnect wires at card terminal R4 and R5.

Connect a VOM to wire removed with scale set to R x 100. With accelerator in creep speed position, the ohms reading should be 4800 to 6000 ohms. If infinity reading is obtained, check AGX 1/4 A fuse. With accelerator in top speed position, reading should be 200 ohms or less.

If readings are not obtained, refer to maintenance section procedure for adjustment in truck manual. With wire disconnected as above, check for resistance of 1 megohm or higher from pot wires to truck frame.

Crown 1979 PF-5030-13 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 013

M4.2 - EV1 - 013

MAINTENANCE Drive Module 24-48V (IC3645CPM1RDA2)

(2) CATHODE (3)

ANODE (1)

a. Connect circuit as shown in Illustration 19. b. Voltmeter should read battery volts with switch open.

LAMP

c. Close switch and meter reading should be 2 volts or less.

6 V. d. Move load resistor to terminal 4 and repeat steps b. and c.

CATHODE (3)

BL

BATT. POS. 24/36 VOLTS

AC

RE

SW. 1

2

3

4

4.7 k OHMS 2 WATTS

ITE WH

3938

BATT. NEG.

SCR’s (1 REC, 2 REC, & 5 REC) These are silicon control rectifiers. Before checking, disconnect battery and discharge capacitor 1C. Disconnect one power connection on the rectifier. Disconnect gate leads of SCR’s at the card plug. To check an SCR, it is necessary to have a 6-volt battery and a 6-volt lamp.

b. The lamp should not light. If the lamp does light, the SCR is shorted and must be replaced.

d. If lamp cannot be lit under step b. the SCR is open and must be replaced.

NOTE If you do not have a test light to check the SCR’s as described above, they may be checked for shorts or opens by use of a VOM.

a. Connect the positive lead to the anode (1) and the negative lead to the cathode (3) as shown in Illustration 20 and 21.

CATHODE (3)

ANODE (1)

THICK END

GATE (2)

(TOP VIEW)

ILLUSTRATION 21

c. If check a. was satisfactory, test the SCR for its ability to be turned on by the gate. Touch gate, point 2, to point 1. If gate is operative, the lamp should come on and must remain on when the gate is removed.

ILLUSTRATION 19

3937

ANODE (1)

D

GATE (2) 50 V D.C. SCALE

3936

K

1. Measure resistance from anode to cathode (R x 100 scale). If SCR is shorted (zero ohms), it must be replaced.

2. Measure resistance from gate lead (white lead) to cathode and then from cathode to gate lead (R x 1 scale). If resistance reads either zero ohms (shorted) or infinity (open), replace the SCR. When reassembling SCR’s, refer to Replacement Procedures.

ILLUSTRATION 20

Crown 1979 PF-5030-14 Rev. 7/95

Printed in U.S.A.

03 REV. 7/95

M4.2–EV1–014

M4.2–EV1–014

MAINTENANCE Hour Meter Module (IC3645CPM1HMB1) 26 REC Check individual diode circuits with continuity light or Simpson. (See Chart 4.)

A0019

ILLUSTRATION 23 Thermal Protector (TP) Remove both connections from TP and with a VOM read less than 200 ohms terminal to terminal, if heat sink is at room temperature. Set VOM to highest ohm scale and check pins to heat sink, reading should be infinity.

A0036

ILLUSTRATION 22

Filter Block (HF) 22 REC, 25 REC, 23 FIL, etc.

Rectifier

To check, disconnect all wires from filter block. With VOM on RX 10,000 scale, touch the lead to the filter terminals to charge the filter. After a few seconds, reverse the meter leads and touch the filter terminals. The VOM needle will deflect and return to infinity. If this capacitor action is not observed, replace the filter block.

When checking diodes, disconnect battery and discharge capacitor 1C to prevent burning out the ohmmeter. When replacing rectifiers, refer to Replacement Procedures.

3 and 4 REC:

NOTE

Disconnect one lead or flexible connection, 3 and 4 REC are diodes with about 7 to 12 ohms in the conducting direction (+ c|−− −) measured on the RX1 scale, and 50,000 ohms or higher, in the non-conducting direction (− c|−− +) measured on the RX 10,000 scale.

If system has symtoms to indicate 22 REC or 25 REC to be defective, interchange 22 REC and 25 REC and try again. If problem is corrected, 25 REC was marginal and should be replaced. If problem is not corrected replace both filters with known good filters.

VOM METER CHECKS

NOTE: When using meter with positive and negative DC switch, be sure meter is set to + DC for check 1, 3 and 5. Meter switch can be reversed to - DC without changing leads for checks 2, 4 and 6.

CONTINUITY LIGHT CHECK

CHART 4

Crown 1979 PF-5030-15 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 015

M4.2 - EV1 - 015

MAINTENANCE Filter Block – 23 RES, etc.

Limit Switch Card

Should these filters fail, it will be evidenced visually by a severe cracking or should read approximately 5 ohms in either direction when checked with an ohmmeter and one lead disconnected.

SP42 (80760-1) a. Check resistance between terminals 51 & 52 resistance should be 20,000 ohms. b. Check resistance between terminals 53 & 54 resistance should be 1,000 ohms.

Transformer and Choke

SP42 (80760-2) a. Check resistance between terminals 51 & 52 resistance should be 15,000 ohms. b. Check resistance between terminals 53 & 54 resistance should be 1,300 ohms.

TRANSFORMER – CHOKE ASSEMBLY

PE - PC (80760-3) to 9/78 a. Check resistance between terminals 51 & 52 resistance should be 39,000 ohms. b. Check resistance between terminals 53 & 54 resistance should be 560 ohms.

PE - PC (83227-2) from 9/78 a. Check resistance between terminals 51 & 52 resistance should be 9,100 ohms. b. Check resistance between terminals 53 & 54 resistance should be 1,500 ohms. c. Check resistance between terminals 51 & 55 resistance should be 3,400 ohms.

A0037

ILLUSTRATION 24 a. Remove shunt from T2; connect to open circuit. b. With VOM on RX1 scale, connect meter leads between T1 and T2 of the transformer. Resistance should be zero ohms. c. Remove 2 REC filters (22 REC) and position leads so they do not touch transformer connections. d. With VOM on RX1 scale, connect meter leads between T3 and T4 of the transformer. Resistance should be zero ohms. e. With VOM on RX 10,000 scale, connect meter leads between T1 and T3 of the transformer. The resistance reading should be infinite resistance. If not, replace transformer. f. With VOM on RX1 scale, connect meter leads between 1X terminals on the transformer and choke block. Resistance should be zero ohms. If a high resistance, replace transformer choke block.

Crown 1979 PF-5030-16 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 016

M4.2 - EV1 - 016

MAINTENANCE

B0002

SCR MODULE PICTORIAL WIRING DIAGRAM

Crown 1979 PF-5030-17 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 017

M4.2 - EV1 - 017

MAINTENANCE TROUBLESHOOTING CHART The pulsing of the main SCR is too fast for conventional instruments to measure. When the control is functioning properly, a low hum can be heard.

Malfunctions of the SCR will generally fall into one of two categories. They are either no power or full power, when operating in the SCR control range and malfunctions of other features.

These simple and easy-to-follow tables outline the various symptoms and the corrective action to be taken.

Before proceeding, visually check for loose wiring, maladjusted linkage to accelerator switch, signs of overheating of components, etc.

CAUTION

Before touching electrical components, disconnect the battery, discharge capacitor 1C, and jack the drive wheels off the floor.

Reconnect the battery as needed for the specific check. Be familiar with both component testing and replacement procedures before proceeding.

If capacitor 1C terminals are not accessible, discharge capacitor by connecting from SCR POS terminal to 2 REC anode. Check resistance on R x 1000 scale from frame to SCR power and control terminals. A resistance of less than 20,000 ohms can cause misleading symptoms. Resistance less than 1000 ohms should be corrected first.

Tools and test equipment required are: (a) 6-volt lamp, 6-volt battery, clip leads, volt-ohm meter (20,000 ohms per volt) and general hand tools, or (b) EV-1 System Analyzer, voltohm meter (20,000 ohms per volt) and general hand tools.

Volt-ohm meter, used for voltage and resistance tests, had 20,000 ohms per volt input impedance with + 2% accuracy full scale on the dc ranges, e.g. a Simpson 260. If meter other than specified is used, be familiar with the meters capabilities so voltage readings and resistance checks obtained are not misleading.

Use the following chart as a reference for voltage readings under various conditions at card test points. If using an Analyzer, use instruction with Analyzer.

Function of EV1 Card Terminals for IC36450SC (All Cards) (All measurements taken with respect to TBR4) Terminal Board No.

Description

Condition

Voltage

L1

Not presently used

L2

Not presently used

L3

Key switch input

Key open Key closed

0 Volts Battery volts

L4

SRO Input

Key or seat open Key & seat closed

0 Volts Battery volts

L5

Accelerator start and brake switch input

Key, seat, brake, or start (accelerator switch) open

0 Volts

Key, seat, brake and start (accelerator switch) closed

Battery volts

No current

1.75 Volts (Approx.)

500 Amps average motor current model “B”

3.25 Volts (Approx.)

Key open Key & seat closed

0 Volts Battery volts

L6

Motor current sensor output

L7

Seat switch input

L8

Not presently used NOTE

If any switch is open before a directional switch is closed, voltage will be 2 to 3 volts less than battery voltage.

Crown 1979 PF-5030-18 Rev. 7/95

Printed in U.S.A.

03 REV. 7/95

M4.2–EV1–018

M4.2–EV1–018

MAINTENANCE

Terminal Board No. L9

Description

Condition

Voltage

Direction switch input from positive side of “F” coil brake & direction “F” closed

Key open Key, seat, start (accel. sw.),

0 Volts Battery volts

L10

Direction switch input from positive side of “R” coil

Key open Key, seat, start (accel. sw.), brake & direction “R” closed

0 Volts Battery volts

R1

Card power supply

Key off Key on

0 Volts 8.2 Volts

R2

Not presently used

R3

Output to PMT Driver

Key off

0 Volts

Direction contactor picked up

2 Volts

Key, seat, start, brake & direction selected (wire removed from R3)

8 Volts (Approx.) or 5–10 Milliamps (See Note 1)

R4

Common Return to card for accelerator pot & 1A switch

Key off, use VOM and read from R4 to “Neg.” Battery disconnected

Less than 1 ohm

R5

Accelerator pot input

Key on & Accelerator “creep”

3.6 Volts (Approx.)

Accelerator top speed

0 Volts (Approx.)

R6

1A switch input

Key on 1A switch closed

Above 7 Volts 0 Volts

R7

% on time output (when used with “B” card remove wire)

Key on Run control with accelerator at top SCR

2.2 Volts (Approx.)

6.0 Volts (Approx.)

R8

1A driver output

1A Contactor open 1A Contactor closed

0 Volts 2 Volts (Approx.)

Top SCR speed (wire removed from R8)

8 Volts (Approx.) or 5–10 Milliamps (See Note 1)

R9

FW driver output

Not used

R10

Plugging output logic

Not plugging mode Plugging mode

0 Volts 8 Volts

NOTE Connect milliammeter from terminal to R4. If contactor picks up during this test, replace driver. If zero milliamps, open lead and recheck to eliminate possible driver short from terminal 1 to 2.

Crown 1979 PF-5030-19 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 019

M4.2 - EV1 - 019

MAINTENANCE ALL TESTING SHOULD BE DONE WITH TRUCK JACKED UP AND HARDWOOD BLOCKS PLACED UNDER TRUCK FRAME DO NOT OPERATE FROM BATTERY CHARGER FAILURES WHICH CAUSE REDUCED OR NO MOTOR TORQUE WITH SCR CONTROL Symptom 1. Contactors do not pick up. No control voltage from positive to negative.

Probable Cause a. Check power and control fuses. Replace if defective. b. Check battery for low specific gravity and connections for looseness or broken fittings. Should have battery volts at positive power terminal.

2. Contactors do not pick up. Control volts present from positive to negative with proper polarity.

Note: All readings at card check points use R-4 as negative test point. a. Check key switch.

Use VOM on 50 V.D.C. scale.

Test for battery volts at L-3 with: Key switch open, reading should be zero volts; key switch closed, reading should be B.V. (Battery Volts). If zero, replace key switch or leads. b. Check seat switch or SRO input.

Use VOM on 50 V.D.C. scale.

Test for battery volts at L-4 and L-7 with: Key and seat switch open, reading should be zero volts; key and seat switch closed, reading should be B.V. If zero, replace seat switch or leads. c. Check brake, start (accelerator), and cutout switches.

Use VOM on 50 V.D.C. scale.

Test for battery volts at L-5 with: Key, seat, brake, etc. switches open, reading should be zero volts.

Sitdown Units Key, seat, brake, accelerator switches closed, reading should be B.V. If zero at L-5, check at TB3-3 for B.V. A zero reading here would indicate the brake switch to be defective. B.V. at TB3-3 would indicate the accelerator switch to be defective.

Stockpicker Units Key, brake and travel cutout switches closed, reading should be B.V. If zero at L-5, check at TB3-16, TB3-17 and TB3-7, etc. to isolate which of the switches or leads are defective.

Stand-up Rider units (RC-PE-PC-PR-SSR-RR-RS) Key and brake switches closed, reading should be BV. at L-5. If zero, replace brake switch or leads.

Crown 1979 PF-5030-20 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 020

M4.2 - EV1 - 020

MAINTENANCE Symptom

Probable Cause d. Check directional (F and R) switches.

Use VOM on 50 V.D.C. scale.

Test for battery volts at L-9 and L-10: Key, seat, brake, etc. switches open, reading should be zero volts.

Key, seat, brake, cutout, start switches and directional switches closed, (as applicable) reading should be B.V. at L-9 for forward and L-10 for reverse. If zero, replace defective directional switch or leads. Note: On sitdown units, the directional switch must be closed after seat switch for system to turn on. e. Check contactor coils (F and R) Use a jumper lead.

Connect jumper lead from negative coil terminal to battery negative. Close key switch, seat, brake switches, etc. Contactor should close. If not, replace defective contactor or leads. Test each coil. f. Check PMT driver.

Use VOM on 50 V.D.C. scale.

Connect negative meter lead to terminal 2 of driver and positive lead to terminal 3. Close switches for forward operation. Meter reading should be 2 volts or less. Repeat same test with positive meter lead on terminal 4 with switches closed for reverse operation. If more, test for signal of 2 volts at R-3 (8 volts with lead disconnected) of card. If voltage at 3 and/or 4 are high and a reading of 2 volts at R-3, replace driver. If voltage is zero at R-3, replace card.

Alternate: Connect milliammeter (10 ma scale) from R3 to R4. Should read 5-10 milliamps. If not, open Key switch, open lead from R3 to PMT driver, reclose all switches except Direction switch, wait over one second and close FORWARD Direction switch. If reading is not 5-10 milliamps, replace control card. If reading is good, the coil or wiring to the PMT driver is open or the PMT driver is defective. Check driver. g. Two possibilities remain keeping F or R from picking up: (1) PMT operating normally (a) Check 1 REC for short (b) Check 1A for welded tips (c) Close key switch.

Check volts at T2 (pin 10). Should be about 50% of battery volts. Above 70% locks out 1 REC. (Control card contains a 10 K bridge from pin 5 to L3 and pin 6). If near battery volts, check for shorted 1A tips or a shorted 1 REC. If near zero volts, check for shorted 3 REC. (2) Replace control card

Crown 1979 PF-5030-21 Rev 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 021

M4.2 - EV1 - 021

MAINTENANCE Symptom

Probable Cause

3. Contactors close. NO power and NO SCR HUM WITH ACCELERATOR IN SCR range.

a. Check SCR power fuse.

Use VOM on 50 V.D.C. scale.

Test for battery volts between positive and negative power terminal studs. If zero, replace fuse. b. Check accelerator circuit. Ref. voltage at RS Use VOM on R x 100 ohm scale.

Disconnect battery. Connect meter lead to R-4 and R-5.

Test: Resistance reading should be approximately 5000 ohms with accelerator in creep speed position and decrease to 200 ohms or less as the 1A switch closes. If reading is infinity, replace fuse and retest. An erratic reading also indicates potentiometer should be replaced even though the correct resistance reading is obtained at both ends of the speed range. c. Check 1 REC. Use continuity light.

Disconnect the gatelead. Disconnect power lead to anode or cathode.

Test: Connect negative to cathode. Connect positive to anode. If light comes on, 1 REC is shorted. If light does not come on, continue test.

Connect jumper between gate terminal and anode. The light should come on and stay on when jumper is removed. If not, 1 REC is open. If this test is done with a three volt flashlight of a continuity tester, it may not be conclusive. The voltage supply may not be adequate to keep the SCR latched on. d. Check 2 REC for open.

Use continuity light or VOM. Disconnect red, white, and black leads. Connect negative tester lead to cathode.

Test: Connect positive tester lead to anode. If light comes on 2 REC is shorted. If light does not come on, continue test. Connect jumper between white gatelead and anode. If light does not come on the SCR is open. Normally, the light should come on. If it does come on and remains on when jumper is removed, 2 REC is good. When using a VOM, consult component testing procedures for readings. e. Check power circuit.

Use VOM on R x 1 scale.

Test: For continuity from 1 REC cathode to battery negative (i.e. motor field and armature, F and R contactor and cables). f. Check current sensor.

Use VOM on R x 1 scale.

Disconnect yellow and green leads from internal terminal board.

Test: Connect meter leads across leads from sensor. Reading should be less than 2 ohms.

Crown 1979 PF-5030-22 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 022

M4.2 - EV1 - 022

MAINTENANCE Symptom

Probable Cause g Check 23 FIL. h. Check control card by replacing.

4. Contactors close, little or no power. Normal SCR hum.

a Check 3 REC for open circuit.

Use continuity light or VOM. Disconnect cathode lead.

Test: With negative lead to cathode and positive lead to anode, light should come on. If not, replace 3 REC. Reverse leads. Light should not come on.

If light does come on, replace 3 REC. When using VOM, consult component testing procedures for readings. b Check 4 REC for short circuit.

Use continuity light or VOM. Disconnect cathode.

Test: Use same test as used in 4a. c. Check thermal protector.

Use VOM. Disconnect one lead.

Test for open. Should be approximately 200 ohms at room temperature.

5. Contactors close. No or little power. Abnormal SCR hum.

a. Check 2 REC for short.

Use continuity light or VOM. Disconnect red, white, and black leads.

Test: Connect negative tester lead to cathode.

Connect positive tester lead to anode. If light comes on, 2 REC is shorted. If light does not come on, continue test. Connect jumper between white gatelead and anode. If light does not come on and remain on when jumper is removed, the SCR is open. Normally, the light should come on. When using VOM, consult component testing procedures for 2 REC. b. Check 5 REC for short.

Use continuity light or VOM. Disconnect red, white, and black leads.

Test: Use same test as in 5a. c. Check 22 REC and 25 REC for short.

Use VOM on R x 10,000 ohm scale.

Remove 22 REC and 25 REC from circuit.

Test: Connect meter lead across terminals. Meter should deflect slightly; reverse meter leads. Again a slight deflection should occur. Then drop to infinity. If other than infinity reading is obtained, replace.

Crown 1979 PF-5030-23 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 023

M4.2 - EV1 - 023

MAINTENANCE Probable Cause

Symptom 6. One contactor closes with normal operation, but opposite contactor will not close.

a. Check directional switches.

Use VOM on 50 V.D.C. scale.

Test: Connect negative meter lead to R-4 and check for battery volts at L-9 for forward or L-10 for reverse with key, seat, brake, etc. switches closed. If a reading of B.V. is not obtained, replace defective directional switch or leads. b. Check directional contactor coils.

Use jumper lead.

Connect jumper lead from negative coil terminal to battery negative. Close key, seat, brake, etc. switches. Contactor should close. If not, replace defective contactor or leads. c. Check PMT driver.

Use VOM on 50 V.D.C. scale.

Test: Connect negative meter lead to terminal 2 of driver and positive lead to terminal 3. Close switches for forward operation. Meter reading should be 2 volts or less. Repeat same test with positive meter lead on terminal 4 with switches closed for reverse operation. If more, test for signal of 2 volts at R-3 (8 volts with lead disconnected) of card. If voltage at 3 and/or 4 are high and a reading of 2 volts is obtained at R-3, replace driver. If voltage is zero at R-3, replace card. d. Check control card by replacing. a. Check 1C capacitor for low resistance.

Use VOM on R x 10,000 scale.

Disconnect lead from capacitor terminal.

Test: Connect the VOM leads across the capacitor terminals. The meter should swing to zero ohms, then gradually swing to above 100,000 ohms. Check from one of the capacitor terminals to its case.

Reading should be at least 50,000 ohms. If either reading is low, replace capacitor.

7. Contactor closes, little power. No SCR hum.

b. Check current limit setting. See setting in Illustration 10 for your unit.

8. PMT trips after operating in 1A and acceleration is returned to SCR range.

Crown 1979 PF-5030-24 Rev. 5/87

a. Check for delay in 1A contactor dropout.

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 024

M4.2 - EV1 - 024

MAINTENANCE

FAILURES WHICH CAUSE FULL MOTOR TORQUE WITH SCR CONTROL Symptom

Probable Cause

1. Contactors close. Full SCR speed immediately with audible hum. NO PMT trip.

a. Check accelerator circuit.

Use VOM on R x 100 scale.

Disconnect lead from R-4 or remove 1/4 A fuse.

Test: Connect meter leads to R-5 and lead removed from R-4 or fuse holder (Pot. side). Resistance should be approximately 5000 ohms in neutral and decrease to less than 200 ohms as 1A switch is closed. If this reading is not obtained, replace potentiometer. On units with limit switches, be sure limit switch is in closed position. b. Check control card by replacing.

2. Contactors close twice and then remain open. PMT operation.

a. Check 5 REC for open circuit.

Use continuity light or VOM. Disconnect red, white, and black leads.

Test: Connect negative tester lead to cathode.

Connect positive tester lead to anode. If light comes on, 2 REC and/or 5 REC are shorted. If light does not come on, continue test.

Connect jumper between white gatelead and anode.

If light does not come on and remain on when jumper is removed, the SCR is open. Normally, the light should come on. If it does come on, this concludes the test using a continuity light. If using a VOM, consult component testing. b. Check 2 REC for open circuit.

Use continuity light or VOM. Test: Same as in 2a. c. Check 1C capacitor for short.

Use VOM on R x 10,000 scale.

Discharge capacitor and disconnect lead from one terminal.

Test: Connect the VOM leads across the capacitor terminals. The meter should swing to zero ohms, then gradually swing to above 100,000 ohms. Check from one of the capacitor terminals to its case.

Reading should be at least 50,000 ohms. If readings are less than shown, replace capacitor. d. Check 22 REC and 25 REC. Use VOM on R x 10,000 scale.

Remove 22 and 25 REC. Test: Connect meter leads across REC to be tested. Meter should momentarily deflect toward zero ohms and then back to infinity. Reverse meter leads. Meter will have a slight movement if REC is good. If test shows REC to be good, it still may be necessary to substitute with a known good REC.

Crown 1979 PF-5030-25 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 025

M4.2 - EV1 - 025

MAINTENANCE Probable Cause

Symptom

e Check control card by replacement. f. Check transformer.

Consult component testing for procedure.

3. Contactors close, but truck double trips under stall SCR operation. Stall current higher than normal and uncontrollable with C/L trimpot.

a. Check current sensor.

Use VOM or R x 1 scale.

Remove either green or yellow lead from internal board.

Test: For less than 2 ohms, resistance between the green and yellow leads. If more than 2 ohms, replace sensor. Check connection of sensor on heat sink and terminal block. b. Check control card by replacing.

MISOPERATION OF FEATURES

Probable Cause

Symptom

a. Check 1A driver.

Use VOM on R x 1 scale.

Remove lead from terminal 3 or 1A driver.

Test: For zero or low ohm between terminals 2 and 3. If low, replace 1A driver.

1. 1A contactor closes with key switch.

b. Check resistance from R4 to SCR negative. If not zero, the control card has been damaged, probably by a high-current input to R4 burning open a run on the card. Check for possible shorts and improper leads being connected to this terminal. Normally only the accelerator pot, 1A switch from R6, and B card use R4 as a negative. c. Check control card by replacing.

2. 1A will not close at run (percent pick up). Units equipped with H-3 and H-9 cards will function only as timed pick up if a jumper is added between R9 to R4.

a. Check connection from control card R-8 to 1A driver terminal 1. b. Check coil continuity. c. Jumper 1A driver terminal 2-3 and close key switch to operate 1A coil. d. Jumper a 4700 ohm resistor (2 watt) from positive to card terminal R-8, with key switch closed, 1A should close. e. Check that motor volts (T2 to neg.) use more than 85% of battery volts. If not, control may be in thermal cutback. Should read 19-21 volts on 24V. units and 29-31 volts on 36V. units. f. Replace control card.

Crown 1979 PF-5030-26 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 026

M4.2 - EV1 - 026

MAINTENANCE Symptom

Probable Cause

3. 1A will not close at SCR stall (time pick up). [Check truck diagram to see if 1A switch closes card circuit R-4 to R-6.]

a. Check 1A switch circuit between card terminals R-4 — R-6.

Use VOM on 50 V.D.C. scale.

Test: For voltage on R-6 with negative meter lead on R-4. Reading should be approximately 7 volts with 1A switch open and zero volts with 1A switch closed. If reading does not drop to zero with switch closed, replace defective switch or leads. b. Measure volts across TP. If volts are above 1.6, (0.6 on B cards) control is in thermal cutback. Allow to cool and recheck 1A action. c. Turn 1A trimpot fully CCW and recheck. d. Check continuity of violet wire from T2 to pin 10. e. Replace control card.

4. PMT does not open F or R contactor.

a. Check PMT Driver Operate drive and place jumper between R3 and R4.

If contactor does not drop out, replace PMT driver. b. Check PMT operation of card.

Operate drive in low speed SCR range. Be sure wheels are turning freely. Push 1A contact tips closed manually. F or R should open, if not, replace control card.

5. Stiff plug. Severe reversal.

a. Check plug adjustment setting on card. b. Check 4 REC for open circuit.

Use VOM or continuity light.

Test: For less than 50 ohms in conducting direction. c. Replace control card. d. See Dual Motor Card Troubleshooting later in EV1 Section.

6. Very soft reversal.

a. Check plug adjustment setting on card.

See plug setting in Illustration 10. b. Replace control card.

7. Blown power fuse. Very hot power cables.

a. Check 3 REC for short. (Possible damage also to 1 REC and transformer module).

Use VOM or continuity light.

Test: For zero or low ohms in non-conducting or both directions.

Crown 1979 PF-5030-27 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 027

M4.2 - EV1 - 027

MAINTENANCE Symptom

Probable Cause

8. Pump contactor closes when either F or R direction is selected. On units equipped with 26 REC.

a. Hour meter feeder diode 26 REC shorted 3 to 4.

Use VOM or continuity light.

Test: For zero ohms in both directions.

9. One direction okay; opposite direction picks up both F and R. On units equipped with 26 REC.

a. Hour meter feeder diode 26 REC shorted 1 to 4 or 2 to 4.

Use VOM or continuity light.

Test: For zero ohms in both directions.

10. Either direction selected picks up both F and R.

a. Hour meter feeder diode 26 REC shorted 1 to 4 and 2 to 4.

Use VOM or continuity light.

Test: For zero ohms in both directions.

Crown 1979 PF-5030-28 Rev. 5/87

Printed in U.S.A.*

02 REV. 5/87

M4.2 - EV1 - 028

M4.2 - EV1 - 028