JLG G12-55A Service Manual - Manual (Page 88)

Axles, Drive Shafts, Wheels and Tires
5-8 G10-55A, G12-55A
5.5 DRIVE SHAFTS
5.5.1 Drive Shaft Inspection and Service
Inspect areas where drive shaft flange yokes and slip
yokes mount to drive shafts. Attempt to turn each drive
shaft in both directions. Look for excessive looseness,
missing parts, cracks or other damage. Worn or damaged
drive shafts and cross and bearing assemblies may
cause an excessive amount of vibration or noise.
Note: To help ensure optimum performance, drive shaft
assemblies are specially balanced as a unit at factory.
When servicing any flange yoke, slip yoke or drive shaft
tube, order a complete assembly if components are bent
or damaged. Refer to the appropriate parts manual for
ordering information.
Note: Any bolt removed from the drive shaft assembly
MUST be replaced. Do Not re-torque.
5.5.2 Drive Shaft Maintenance
Refer to Section 2.5, “Fluids and Lubricant Capacities,”
for information regarding lubrication of drive shafts.
5.5.3 Drive Shaft Removal
1. Park machine on a firm, level surface, level machine,
fully retract boom, lower boom, place transmission
control lever in (N) NEUTRAL, engage park brake and
shut engine OFF.
2. Place a Do Not Operate Tag on both the ignition key
switch and steering wheel.
3. Open engine cover. Allow the system fluids to cool.
4. Properly disconnect the batteries.
5. Block the wheels.
6. The drive shaft assembly is a balanced assembly.
Mark yoke and axle, transmission and shaft and slip
yoke so that these components can be returned to
their original positions when reinstalled. Yokes at
both ends of drive shaft must be in same plane to
help prevent excessive vibration.
7. Remove four bolts and two straps (1) securing
bearing cross to the transmission output shaft
flange. Discard bolts.
8. Remove four bolts and two straps (2) securing
bearing crosses to the axle. Discard bolts.
9. Remove front drive shaft assembly (3).
10. Remove four bolts and two straps (4) securing
bearing cross to transmission output shaft flange.
Discard bolts.
11. Remove four bolts and two straps (5) securing
bearing crosses to rear axle (6) at carrier bearing.
Discard bolts.
12. Remove rear drive shaft assembly (6).
13. Remove four bolts and two straps (7) securing
bearing cross to rear axle. Discard bolts.
14. Remove two bolts, nuts and washers (8) securing
carrier bearing to frame.
15. Remove rear drive shaft assembly (9).
5.5.4 Drive Shaft Cleaning and Drying
1. Disassemble and clean all parts using an approved
cleaning fluid. Allow to dry.
2. Remove and burrs or rough spots from all machined
surfaces. Re-clean and dry as required.
5.5.5 Drive Shaft Installation
1. Raise drive shaft assembly into position. Slip-yoke
end of drive shaft mounts toward axle. If reinstalling
a drive shaft previously removed, align flange yokes
according to alignment marks made during removal.
MAL2220
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