DI-34
General Diagnostic Table
DIFFERENTIALS
8. General Diagnostic Table
A: INSPECTION
Symptom or trouble Possible cause Remedy
1. Oil leakage(1) Worn, scratched, or incorrectly seated
front or side oil seal. Scored, battered or
excessively wor n sliding surface of com-
panion flange.
Correct or replace.
(2) Clogged or damaged air breather. Clean, repair or replace.
(3) Loose bolts on differential spindle or
side retainer, or incorrectly fitted O-ring.
Tighten the bolts to specified torque.
Replace the O-ring.
(4) Loose rear cover attaching bolts or
damaged gasket.
Tighten the bolts to specified torque.
Replace gasket and apply liquid gasket.
(5) Loose oil filler or drain plug. Retighten and apply liquid gasket.
(6) Wear, damage or incorrect fitting of
spindle, side retainer or oil seal.
Correct or replace.
2. Seizure
NOTE:Seized or damaged parts should be re-
placed, and also other parts should be thor-
oughly checked for any defect and should
be repaired or replaced as required.
(1) Insufficient backlash for hypoid gear. Readjust or replace.
(2) Excessive preload for side, rear or
front bearing.
Readjust or replace.
(3) Insufficient or improper oil used. Replace seized part and fill with speci-
fied oil to specified level.
3. Damage
NOTE:Damaged parts should be replaced, and
also other parts should be thoroughly
checked for any defect and should be re-
paired or replaced as required.
(1) Improper backlash for hypoid gear. Replace.
(2) Insufficient or excessive preload for
side, rear or front bearing.
Readjust or replace.
(3) Excessive backlash for differential
gear.
Replace gear or thrust washer.
(4) Loose bolts and nuts such as hypoid
driven gear bolt
Retighten.
(5) Damage due to overloading. Replace.
4. Noises when starting or shifting
gears
NOTE:
Noises may be caused by differential as-
sembly, universal joint, wheel bearing, etc.
Find out what is actually making noise be-
fore disassembling.
(1) Excessive backlash for hypoid gear. Readjust.
(2) Excessive backlash for differential
gear.
Replace the differential case assembly.
(3) Insufficient preload for front or rear
bearing.
Readjust.
(4) Loose drive pinion nut. Tighten to the specified torque.
(5) Loose bolts and nuts such as side
bearing retainer attaching bolt.
Tighten to the specified torque.
5. Noises when cornering(1) Damaged differential gear. Replace the differential case assembly.
(2) Excessive wear or damage of thrust
washer.
Replace the differential case assembly.
(3) Broken pinion mate shaft. Replace the differential case assembly.
(4) Seized or damaged side bearing. Replace.
6. Gear Noise
NOTE:
Since noises from engine, muffler, trans-
mission, propeller shaft, wheel bearings,
tires, and body are sometimes mistaken for
noises from differential assembly, be care-
ful in checking them. Inspection methods to
locate noises include coasting, accelerat-
ing, cruising, and jacking-up all four wheels.
Perform these inspections according to the
condition of trouble. When listening to nois-
es, shift gears into four wheel drive and
fourth speed position, trying to pick up only
differential noise.
(1) Improper tooth contact of hypoid gear. Readjust or replace hypoid gear set.
(2) Improper backlash of the hypoid gear. Readjust.
(3) Scored or chipped teeth of hypoid
gear.
Replace hypoid gear set.
(4) Seized hypoid gear. Replace hypoid gear set.
(5) Improper preload for front or rear
bearings.
Readjust.
(6) Seized, cut-away or chipped front or
rear bearing.
Replace.
(7) Seized, cut-away or chipped side
bearing.
Replace.
(8) Differential carrier is vibrating. Replace the differential case assembly.
