3–4 STEERING LINKAGE

3–4.1 Adjustment of the Steering Linkage

Lift the loader and put jackstands under the frame so there is no danger of the loader falling and causing personal injury.

DO NOT work on the loader with the lift arms in a raised position without support. Use lift arm stop or other methods.

1.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

2.Loosen the nuts and bolts at the steering levers (Fig. 3–13).

3.Loosen the nuts and bolts at the pintle levers (Fig. 3–14).

4.Loosen the nuts and bolts at steering linkage at the steering lever.

5.Start the engine and run at a slow RPM (See Paragraph 5–1.3).

6.Move the left steering lever until the tires do not turn (neutral).

7.Adjust the rear pintle bar (Fig. 3–15) so that the bar is tight against both lobes of the pintle lever and the transmission is still in the neutral position. Tighten the bolts on the bar to 28 ft.–lbs. (38 Nm) torque.

8.Move the left steering lever forward and backward and let the transmission return to the neutral position. If the transmission does not return to the neutral position, make the adjustment again.

9.Move the right steering lever until the tires do not turn (neutral).

10.Adjust the front pintle bar so that the bar is tight against bolt lobes of the pintle lever and the transmission is still in the neutral position (Fig. 3–16). Tighten the bolts on the bar to 28 ft.–lbs. (38 Nm) torque.

11.Move both steering levers forward and backward and let them return to neutral position, make the adjustment if the transmission does not return to neutral.

12.Install new locknuts on each bolt that holds the steering linkage to the pintle levers and tighten to 23 ft.–lbs. (31 Nm) torque.

13.Install new locknuts on the bolts at the front end of the steering linkage and tighten to 23 ft.–lbs. (31 Nm) torque.

14.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

15.Remove the jackstands from under the loader frame.

3–4.2 Removing the Steering Linkage

1.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

2.Remove the nuts and bolts at the steering levers (Fig. 3–17).

3.Remove the nuts and bolts at the pintle lever (Fig. 3–18).

4.Remove the bolts and nut at the bar by the centering spring (Fig. 3–19).

5.Loosen the bolts at the pintle levers.

6.Remove the centering bar, bushings and pintle levers as an assembly from the hydrostatic pumps (Fig. 3–20).

3–4.3 Repairing the Pintle Lever

1.Remove the lobes from the pintle lever (Fig. 3–21).

2.Remove the rubber bushing from the pintle lever.

3.Install the new rubberbushings, using two (2) sockets and a vise (Fig. 3–22) in the pintle lever.

4.Install the new lobes on the pintle lever and tighten the bolts to 25–28 ft.–lbs. (34–38 Nm) torque (Fig. 3–23).

3–4.4 Installing the Steering Linkage

1.Install the bushing and guide in the pintle lever.

2.Install the key on the shaft of the hydrostatic pump (Fig. 3–24) and install the pintle lever assembly.

3.Tighten the bolt on the pintle lever to 18–20 ft.–lbs. (24–27 Nm) torque.

4.Install the centering bar into the teflon guides on the front and rear pintle levers.

5.Install the bar on the centering spring bolt.

6.Install the bolt in the bar and tighten.

7.Adjust the centering spring bolt until it is even with the bar onthe back side (Fig. 3–25).

8.Install the steering linkages on the pintle levers and the steering levers. Install the bolts and new locknut. DO NOT tighten them.

9.Make the adjustment to the steering linkage (See Paragraph 3–4.1).

3–5 PORT BLOCK

3–5.1 Removing the Port Block

Important

Always use caps or plugs in openings or ports to keep debris out of the hydrostatic system.

1.Stop the engine, remove the hydraulic/hydrostatic fluid from the reservoir (See paragraph 1–5.3, Page 1–12).

2.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

3.Remove the hose at the control valve (Fig. 3–26).

4.Remove the hose at the port block (Fig. 3–27).

5.Remove the large nut at the top of the port block (Fig. 3–28).

6.Loosen the slotted bolt and remove the port block from the hydraulic pump (Fig. 3–29).

3–5.2 Installing the Port Block

1.Clean all the parts in solvent before assembling. Install new o–rings.

2.Install the port block and tighten the slotted bolt to 90–100 ft.–lbs. (125–135 Nm) torque.

3.Install the large nut and tighten (Fig. 3–28).

4.Connect the hose at the port block and tighten (Fig. 3–27).

5.Connect the hose at the control valve and tighten (Fig. 3–26).

6.Add fluid to the hydraulic/hydrostatic reservoir (See Section 8 for the correct fluid).

7.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

1.Stop the engine. Remove the hydraulic/hydrostatic fluid from the reservoir (See Paragraph 1–5.3, Page 1–12).

2.Remove the hose from the port block (Fig. 3–30).

3.Remove the fitting from the port block.

4.Remove the spring and valve (Fig. 3–31).

5.Clean and inspect the parts, replace as needed.

6.Install new o–ring and install the valve, spring and fitting.

7.Connect the hose to the port block and tighten (Fig. 3–30).

8.Add the correct fluid to the reservoir (See Section 8 for the correct fluid).

9.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

3–6 HYDROSTATIC MOTOR

Important

When making repairs on the hydrostatic system, keep all parts clean and remove all the dirt from the area before you begin disassembly. Always use caps or plugs to keep debris out of the system.

Warning

Lift and causing personal injury.

Warning

DO NOT work on the loader with the lift arms in a raised position without support. Use lift arm stops or other methods.

2.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

3.Remove the hydrostatic pumps (See Paragraph 3–7.4).

4.Remove the cover/brake assembly (See Paragraph 4–1.2, Page 4–1).

5.Only the front drive chain has to be removed so that the motor can be removed (See Paragraph 4–2.1, Page 4–5).

6.Remove the motor cover bolts (Fig. 3–32).

7.Remove the motor cover (Fig. 3–33).

8.Disconnect the case drain hose (Fig. 3–34).

9.Disconnect the high pressure hoses (Fig. 3–35).

10.Remove the hydrostatic motor bolts (Fig. 3–36).

11.Move the hydrostatic motor so that the rear drivechain can be removed from the motor sprocket. Remove the motor from the loader.

3–6.2 Disassembly of the Hydrostatic Motor the motor in a vise, remove the bolts holding the end cover to the motor (Fig. 3–38).

NOTE:Clean the outside of the motor before disassembly. Keep all the parts of the motor clean.

1.Remove the sprocket from the motor with a hydraulic press or a puller (Fig. 3–37).

6.Remove

7.Remove

8.Remove

13.Remove the shuttle spring (Fig. 3–50).

14.Remove the shuttle valve (Fig. 3–51).

15.Remove the drive shaft (Fig. 3–52).

16.Turn the flange housing over in the vise, using a snap ring pliers, remove the snap ring (Fig. 3–53).

17.Remove the spacer (Fig. 3–54).

18.Remove the back–up washer and seal (Fig. 3–55).

3–6.3 Inspection of the

Clean and inspect all the parts for scratches, wear and damage, make an inspection of the following parts:

(a)Housing Wear Plate (Fig. 3–56).

(b)Install the stator ring and rotor assembly (Fig. 3–73).

(c)Manifold Plate Fig. 3–58).

(d)Stator and Rotor Assembly (Fig. 3–59).

(e)Wear Plate (Fig. 3–60).

(f)Commutator Ring (Fig. 3–61).

(g)Shuttle Valve & Shuttle Springs

3–6.4 Assembling the Hydrostatic Motor

The tools listed will be needed to do the following procedure:

MEL–1017 Seal Installation Tool

1.Clean all the parts throughly and use all new seals and o–rings. Put fluid on all the parts during assembly.

2.Using the seal installation tool, install the rubber seal inside the housing with the lip of the seal to the inside of the motor (Fig. 3–62).

3.Install the spacer with the chamfer toward the housing (Fig. 3–63).

4.Install the snap ring in the housing (Fig. 3–64).

5.Turn the housing over in the vise, install a new o–ring (Fig. 3–65).

14.Install

3–6.5 Installing the Hydrostatic Motor

1.Install the hydrostatic motor so that the rear drive chain can be installed on the motor sprocket.

2.Install the bolts into the motor housing and tighten the bolts to 100–110 ft.–lbs. (136–149 Nm) torque (Fig. 3–81).

3.Connect the high pressure hoses to the motor (Fig. 3–82).

4.Connect the case drain hose (Fig. 3–83).

5.Install the motor cover (Fig. 3–84).

6.Install the motor cover bolts and tighten (Fig. 3–85).

7.Install the front drive chain (See Paragraph 4–2.2, Page 4–6).

8.Tighten the nut at the end of the sprocket on the motor shaft to 260–300 ft.–lbs. (352–407 Nm) torque.

9.Install the cover/brake assembly (See Paragraph 4–1.4, Page 4–3).

10.Install the hydrostatic pumps (See Paragraph 3–7.8).

11.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

12.Add the correct fluid to the reservoir (See Section 8 for the correct fluid).

3–6.6 Start–Up Procedure for the Hydrostatic Motor

Because of the close tolerances in the hydrostatic motor, it is important that the motor is NOT OPERATED WITHOUT A LOAD when the motor is first used after being repaired.

The motor must be replaced under a “full load” condition for at least 10 minutes. “Full load” can be done by pushing some heavy object or material.

Important

When making repairs on the hydrostatic system, keep all parts clean and remove all the dirt from the area before you begin disassembly. Always use caps or plugs to keep debris out of the system.

3–7.1 Checking the High Pressure Relief Replenishing Valves

If there is a loss of drive in one direction,to one side of the loader, use the following procedure to check the high pressure relief replenishing valves:

NOTE:Check the hydrostatic pump on the side only where thedrive is lost.

Warning

Lift the loader and put jackstands under the loader frame so there is no danger of the loader falling and causing personal injury.

Warning

DO NOT work on the loader with the lift arms in a raised position without support. Use lift arm stops or other methods.

1.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

2.Remove the plug for one direction.

3.Remove the spring and high pressure relief replenishing valve (Fig. 3–86).

4.Remove the plug for the other direction.

5.Remove the spring and high pressure relief replenishing valve.

6.Change the valves to the opposite ports where they were removed.

7.Install the springs and plugs. Start the engine and check the drive.

8.If the loss of the drive goes to the other direction of the loader, the valve which controls that direction of the loader must be replaced.

9.If the changing of the valves does not change the direction of loss of drive. The problem is somewhere else in the system, go to the troubleshooting chart for other possible causes.

10.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

11.Remove the jackstands from under the loader frame.

3–7.2 Checking the Charge Pressure

The tools listed will be needed to do the following procedure: MEL–1173 – Test Kit

Warning

Lift the loader and put jackstands under the loader frame so there is no danger of the loader falling and causing personal injury.

Warning

DO NOT work on the loader with the lift arms in a raised position without support. Use lift arm stops or other methods.

1.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

2.Disconnect the wire from the pressure switch on the side of the hydrostatic pump.

3.Remove the pressure switch.

4.Connect a pressure gauge (Fig. 3–87).

5.Start the engine and run it at 2500 RPM.

6.The pressure on the gauge must read 45–65 PSI (310–448 kPa) minimum with no hydraulic action.

7.If the pressure is not correct, remove the plug (Fig. 3–88) and remove the spring and poppet (Fig. 3–89).

8.Check the poppet and seat area, replace parts as needed or repair hydrostatic pump (See Paragraph 3–7.5).

9.Replace the poppet and spring, tighten the plug.

10.Remove the gauge, install the pressure switch and connect the wire.

11.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

12.Remove the jackstands from under the loader frame.

3–7.3 Cold Weather By–Pass Valve

If the “TRANS” indicator light continues to go “ON” and “OFF” and you do not notice any poor hydrostatic performance, the by–pass valve can be the problem.

1.Stop the engine. Remove the hydraulic/hydrostatic fluid from the reservoir (See Paragraph 1–5.3, Page 1–12).

2.Disconnect the hose from the port block. Remove the poppet and spring out of the port block (Fig. 3–90).

3.Check the spring and poppetfor damage or binding in the seat area.

4.Assembly is the reverse of disassembly.

3–7.4 Removing the Hydrostatic Pumps

Warning

DO NOT work on the loader with the lift arms in a raised position without support. Use lift arm stop or other methods.

Lift the loader and put jackstands under the loader frame so there is no danger of the loader falling and causing personal injury.

1.Raise the operator guard (See Paragraph 5–1.1, Page 5–1).

2.Remove the front panel.

3.Remove the side shields (both sides).

4.Remove the steering linkage at the steering levers (Fig. 3–91).

5.Remove the steering linkage at the pintle arms (Fig. 3–92).

6.Remove the fluid from the hydraulic/hydrostatic reservoir (See Paragraph 1–5.3, Page 1–12).

7.Remove the hoses from the hydraulic pump (Fig. 3–93) and from the port block.

8.Remove the high pressure hoses from the hydrostatic pumps (Fig. 3–94, 3–95) and install caps and plugs.

9.Remove the front pump mount bolts (both sides) (Fig. 3–96).

10.Remove the bolts (both sides) from the rear of the hydrostatic pump (Fig. 3–97).

11.Slide the pump assembly forward and lift up on it to remove it from the loader (Fig. 3–98).

Important

Keep all the hydrostatic parts clean. Dirt in the system will cause damage in a very short time.

1.Remove the steering linkage from the hydrostatic pumps (See Paragraph 3–4.2).

2.Remove the port block from the hydraulic pump (See Paragraph 3–5.1).

3.Remove the hydraulic pump (See Paragraph 2–4.2, Page 2–11).

4.Remove the coupler assembly from the pump shaft (Fig. 3–99).

5.Put a mark across all the pump sections for correct assembly.

6.Remove the plug and the high pressure replenishing valves (both sides) (Fig. 3–100).

7.Remove the plug and the charge pressure spring and poppet (both sides) (Fig. 3–101).

8.Remove the four (4) bolts from the housing and center section (Fig. 3–102).

9.Separate the pump housing from the center section (Fig. 3–103).

10.Remove the coupling from the center section (Fig. 3–104).

11.Remove the four (4) bolts from the other housing and center section (Fig. 3–105) and remove the pump housing.

12.Put the pump housing in a vise. Remove the snap ring from the shaft (Fig. 3–106).

13.Remove the race from the shaft (Fig. 3–107).

Keep all the parts for one pump separated from the parts for the other pump.

14.Remove the pump housing from the vise and remove the rotating group by putting your hand under the rotating group and turn the pump housing around so the rotating group will slide into your hand (Fig. 3–108).

15.Turn the front housing around and hit the shaft on a block of wood to remove the shaft from the housing (Fig. 3–109).

16.Remove the snap ring (Fig. 3–110) from the rear housing and hit on a block of wood to remove the bearing and shaft (Fig. 3–111).

17.Remove the back–up washer (Fig. 3–112).

18.Using a punch, remove the seal from the rear housing (Fig. 3–113).

19.Remove the snap ring (Fig. 3–114) and the bearing from the shaft for the rear housing.

20.Remove the cover on the long pintle shaft (Fig. 3–115).

21.Remove the o–rings from the shaft (Fig. 3–116).

22.Remove the cover from the short pintle shaft (Fig. 3–117).

23.Remove the o–rings from the shaft (Fig. 3–118).

24.Loosen the bolts on the cam plate (Fig. 3–119) and remove the bolts.

25.Remove the pintle shafts from the cam plate and remove the cam plate from the housing (Fig. 3–120).

26.Check the pintle shaftbearings, if they need replacing, use a press to remove and install the new bearing (Fig. 3–121).

27.Check the bearings in the center section, use a punch to remove them (Fig. 3–122) and a press to install the new bearings.

IMPORTANT

Keep all the parts for one pump separated from the parts for the other pump.

1.Check the drive shafts for wear and damage to the splines (Fig. 3–123).

2.Inspect the flat surface of the center section, front and rear (Fig. 3–124). The finish on the piston block side must be smooth and free of grooves. If grooves can be felt on the finished surface with a fingernail, replace the section.

3.Inspect the rotating group for the following items:

(a)Check each piston in its cylinder. he piston must move freely in the bore. If the piston does not move easily, clean the piston and bore. Put oil on both and try again.

(b)Check the piston shoe for scratches (Fig. 3–125).

This Dimension Must be Maintained on All Nine Shoes Within 0.001 in. (0,0254 mm)

Shoe Faces Sides On Swash Plate

(c)Check the flat surface of the piston block for being smooth and free of scratches (Fig. 3–126).

(d)Check the end play of each piston assembly. End play must not be more than 0.003” (0,076 mm) between the piston and the shoe (Fig. 3–127).

(e)Measure the thickness of each shoe. All the shoes must be within 0.001” (0,025 mm) of each other.

Shoe Must Swivel Smoothly on Ball, End Play Must Not Exceed .003 in. (0,076 mm)

(f)Inspect the shoe plate for wear and cracks.

(g)Inspect the pins and spherical washer for wear and damage (Fig. 3–128). All the pins must be the same length and must not be bent. Check the spherical washer for sharp edges, wear or scratches.

NOTE:If there is any defect in the rotating group, the complete unit must be replaced.

4.Inspect the cam plate for scratches in the pintle shaft area. Inspect the cam plate plate (Fig. 3–129), the finish must be smooth and free of grooves. If grooves can be felt with the fingernail, replace the cam plate plate.

5.Inspect the races for the center section bearings (Fig. 3–130).

3–7.7 Assembling the Hydrostatic Pumps

Important

Use a top grade grease such as Dow Corning #44 or Vaseline petroleum jelly to lubricate the seals, o–rings or bearings.

NOTE:Always use a NEW seal kit when assembling the hydrostatic pumps.

1.Install the key in the cam plate housing (Fig. 3–131).

2.Install the cam plate housing into the housing (Fig. 3–132).

3.Install the pintle shafts into the cam plate housing.

4.Install the bolts into the cam plate housing and tighten to 45 ft.–lbs. (61 Nm) torque (Fig. 3–133).

5.Install the o–rings on the pintle shafts (Fig. 3–134 & 1–135).

6.Install the covers on the pintle shafts (Fig. 3–136 & 3–137) and tighten the bolts.

7.Install the bearings on the shafts.

8.Install the seal in the rear housing.

9.Install the back–up washer in the housing (Fig. 3–138).

10.Install the shaft into the housing and install the snap ring (Fig. 3–139).

11.Install the rotating group on the shaft and into the pump housing.

12.Put the pump housing into a vise. Install the bearing race for the center section (Fig. 3–140).

13.Install the snap ring on the shaft (Fig. 3–141).

Race

14.Install the pump housing to the center section and tighten the bolts to 42 ft.–lbs. (57 Nm) torque (Fig. 3–142).

15.Install the coupling into the center section on the shaft of the pump (Fig. 3–143).

B–05382

Fig. 3–142 Installing Pump Housing

Fig. 3–143 Installing Coupling

B–05384

16.Install the other pump housing and tighten the bolt to 42 ft.–lbs. (57 Nm) torque (Fig. 3–144).

B–05381

Fig. 3–144 Installing Pump Housing

17.Install the charge relief poppet and spring into the center section and tighten the plug (Fig. 3–145).

B–05380

Fig. 3–145 Installing Poppet & Spring

18.Install the high pressure relief replenishing valves and tighten the plug (Fig. 3–146).

B–05379

19.Install the hydraulic pump on the hydrostatic pump on the hydrostatic pump assembly (See Paragraph 2–4.6, Page 2–15).

Fig. 3–146 Installing Valves

20.Install the port block on the hydraulic pump (See Paragraph 3–5.2).

21.Install the coupler assembly on the shaft of the hydrostatic pump (Fig. 3–147) and tighten the bolt to 25–28 ft.–lbs. (34–38 Nm) torque.

22.Install the steering linkage on the hydrostatic pump (See Paragraph 3–4.4).

1.Put the hydrostatic pump assembly into the loader (Fig. 3–148), slide the pump assembly into the engine coupler.

2.Install the bolts at the rear of the hydrostatic pump and tighten to 65–70 ft.–lbs. (88–95 Nm) torque (Fig. 3–149).

3.Install the front mounting bolts and tighten to 65–70 ft.–lbs. (88–95 Nm) torque (Fig. 3–150).

4.Install the high pressure hoses and tighten (Fig. 3–151 & 3–152).

5.Install the hoses on the hydraulic pump and the port block (Fig. 3–153).

6.Install the steering linkage at the pintle arms and the steering levers (Fig. 3–154 & 3–155).

7.Install the side shields.

8.Install the front panel.

9.Add fluid to the hydraulic/hydrostatic reservoir (See Section 8 for the correct fluid).

10.Before you start the engine on the loader (See Paragraph 3–7.9 for the correct start–up procedure).

11.Adjust the steering linkage (See Paragraph 3–4.1).

12.Lower the operator guard (See Paragraph 5–1.2, Page 5–1).

13.Remove the jackstands from under the loader frame.

3–7.9 Hydrostatic Pump Start–Up Procedure

1.Make sure all the hoses and tubelines are tight.

2.Check the hydraulic/hydrostatic reservoir, make sure the fluid level is correct.

3.Put the steering levers in the neutral position.

4.Start the engine and run at a slow RPM. The chargepump must immediately pick up fluid and fill the system. If there is no sign of a fill in 30 seconds, stop the engine and check for the cause.

5.After the system is full, at a slow rate move the steering levers into forward position. Operate the system at a slow rate with no load until the system is at normal operation.

6.Stop the engine. Check the reservoir. Add fluid as needed.

7.Check all the tubelines and hoses to make sure there are no leaks.

8.Go back to Step 11 of installing the Hydrostatic Pump.

NOTE:The Oil Cooler Removal and Installation is located in the Hydraulic Section, Paragraph 2–8.

DO NOT service the Bobcat loader without instructions or taking the necessary safety precautions. Before working on the loader, see the warnings and instructions at the beginning of this Service Manual. After making the repair or adjustment, always check the function of the loader. Failure to obey warnings may cause injury or death.