Jeep 1997 Grand Cherokee Service Manual page 76

3 - 18 DIFFERENTIAL AND DRIVELINE
DIAGNOSIS AND TESTING (Continued)
FRONT AXLES
CONDITION
WHEEL NOISE
AXLE SHAFT NOISE
AXLE SHAFT BROKE
DIFFERENTIAL CASE
CRACKED
DIFFERENTIAL GEARS
SCORED
LOSS OF LUBRICANT
POSSIBLE CAUSES
1. Wheel loose.
2. Faulty, brinelled wheel bearing.
1. Misaligned axle shaft tube.
2. Bent or sprung axle shaft.
3. End play in drive pinion bearings.
4. Excessive gear backlash between ring gear
and pinion gear.
5. Improper adjustment of drive pinion gear
shaft bearings.
6. Loose drive pinion gearshaft yoke nut.
7. Improper wheel bearing adjustment.
8. Scuffed gear tooth contact surfaces.
1. Misaligned axle shaft tube.
2. Vehicle overloaded.
3. Erratic clutch operation.
4. Grabbing clutch.
1. Improper adjustment of differential bearings.
2. Excessive ring gear backlash.
3. Vehicle overloaded.
4. Erratic clutch operation.
1. Insufficient lubrication.
2. Improper grade of lubricant.
3. Excessive spinning of one wheel/tire.
1. Lubricant level too high.
DIAGNOSIS
1. Tighten loose nuts.
2. Faulty or brinelled bearings must be
replaced.
1. Inspect axle shaft tube alignment. Correct as
necessary.
2. Replace bent or sprung axle shaft.
3. Refer to Drive Pinion Bearing Pre-Load
Adjustment.
4. Check adjustment of ring gear backlash and
pinion gear. Correct as necessary.
5. Adjust drive pinion shaft bearings.
6. Tighten drive pinion gearshaft yoke nut with
specified torque.
7. Readjust as necessary.
8. If necessary, replace scuffed gears.
1. Replace broken axle shaft after correcting
axle shaft tube alignment.
2. Replace broken axle shaft. Avoid excessive
weight on vehicle.
3. Replace broken axle shaft after inspecting for
other possible casues. Avoid erratic use of
clutch.
4. Replace broken axle shaft. Inspect clutch and
make necessary repairs or adjustments.
1. Replace cracked case; examine gears and
bearings for possible damage. At reassembly,
adjust differential bearings properly.
2. Replace cracked case; examine gears and
bearings for possible damage. At reassembly,
adjust ring gear backlash properly.
3. Replace cracked case; examine gears and
bearings for possible damage. Avoid excessive
weight on vehicle.
4. Replace cracked case. After inspecting for
other possible causes, examine gears and
bearings for possible damage. Avoid erratic use
of clutch.
1. Replace scored gears. Scoring marks on the
drive face of gear teeth or in the bore are
caused by instantaneous fusing of the mating
surfaces. Scored gears should be replaced. Fill
rear differential housing to required capacity
with proper lubricant. Refer to Specifications.
2. Replace scored gears. Inspect all gears and
bearings for possible damage. Clean and refill
differential housing to required capacity with
proper lubricant.
3. Replace scored gears. Inspect all gears,
pinion bores and shaft for damage. Service as
necessary.
1. Drain excess lubricant by removing fill plug
and allow lubricant to level at lower edge of fill
plug hole.
CORRECTION
ZG