Model 4700 Maintenance Manual

Section 7.Component Procedures

Mast Quad Mast Service

Quad Mast Service

Mast Inspection

During normal scheduled maintenance checks, pry between the upright and load roller so the opposite load roller is tight against the upright. Measure the clearance for the pair of rollers at XXX shown in Figure7-98.

1.Remove the internal hose reeving from the mast while it is on the truck.

2.Remove the mast assembly from the truck. Refer to “Mast Removal and Installation” on page7-68.

3.Remove the main lift cylinders from the mast. Refer to “Cylinder Removal and Installation” on page7-84.

4.Using an overhead chain hoist, turn the mast over (face up).

5.Remove the free lift cylinder from the mast. Refer to “Free Lift Cylinder Removal - Mast on Floor” on page7-85

6.Remove the carriage from the mast. Refer to “Removal - Mast on Floor” on page7-84

7.Remove the free lift chain anchors and chains from the inner upright center cross member and tag for reassembly.

8.Disconnect the free lift cylinder hose from the tube and remove the stop/hose bracket/tube assembly.

9.Disconnect the inner main chain anchors from the lower end of the inner upright and the upper end of the outer intermediate upright.

10.Move the inner upright downward. Remove the free lift hose sheave, hose, and main chain sheaves at the top of the inner intermediate upright.

NOTE : Raise the lower end of the inner upright slightly to clear the inner intermediate upright lower cross member.

Each pair of load rollers on the uprights and carriage should be shimmed so that a total side to side clearance no greater than 0.06 in. (1.5mm) occurs at the tightest point throughout the travel of the member.

Disassembly

NOTE : Quad Mast uprights require complete disassembly in order to service load rollers, thrust plugs/blocks, and chain/hose sheaves.

Refer to Figure7-99

11.Remove the inner main lift chains and tag for reassembly.

12.Remove the load rollers from the lower end of the inner upright. Remove the load rollers and thrust plugs from the upper end of the inner intermediate upright. Note the number of shims behind each for reassembly.

13.Attach an overhead hoist to the inner upright and remove it through the top end of the inner intermediate upright.

NOTE : The stub shafts on the lower end of the inner upright come out of the inner intermediate upright between the rail cutout and the stub shaft.

Publication 1160093, Issued: 20 May 2013 7-79

Section 7.Component Procedures

Model 4700 Maintenance Manual

14.Remove the outer main lift chain anchors from the lower end of the inner intermediate upright and the top end of the outer upright. Set the chains aside and tag for reassembly.

15.Remove the lower stop from the outer intermediate upright.

16.Remove the chain sheaves from the outer intermediate upright.

17.Roll the inner intermediate upright downward and remove the lower rollers. Remove the upper rollers and thrust plugs from the outer intermediate upright. Note the number of shims behind each roller for reassembly.

18.Attach an overhead hoist to the inner intermediate upright and remove it through the top end of the outer intermediate upright.

19.Roll the outer intermediate upright downward and remove the lower rollers. Remove the upper rollers and thrust blocks from the outer upright. Note the number of shims behind each roller and thrust block for reassembly.

20.Attach an overhead hoist to the outer intermediate upright and remove it through the top end of the outer upright.

Note: Bubbled numbers refer to steps in associated procedure.

Reassembly

1.Lubricate the full length of the outer upright rails. See “Lubrication Specification Chart” on pageA-2.

2.Attach an overhead hoist to the outer intermediate upright and install it through the top of the outer upright. Position it out the lower end of the outer upright approx. 6in. (15 cm).

3.Assemble shims, load rollers, and thrust blocks to the upper end of the outer upright. Assemble shims and load rollers

Publication 1160093, Issued: 20 May 2013

Quad Mast Service Mast 7-80