four wheel drive SUBARU LEGACY 1999 Service Repair Manual

2. Rear Differential
Symptom Possible cause Remedy
1. Oil leakage(1) Worn, scratched, or incorrectly seated front or
side oil seal. Scored, battered, or excessively worn
sliding surface of companion flange.Repair 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 bolts to specified torque.
Replace O-ring.
(4) Loose rear cover attaching bolts or damaged
gasket.Tighten bolts to specified torque.
Replace gasket and apply liquid
packing.
(5) Loose oil filler or drain plug. Retighten and apply liquid packing.
(6) Wear, damage or incorrectly fitting for spindle,
side retainer and oil seal.Repair or replace.
2. Seizure
NOTE:
Seized or damaged parts should
be replaced, and also other parts
should be thoroughly 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
specified 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 repaired
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 crown gear bolt. Retighten.
(5) Damage due to overloading. Replace.
4. Noises when starting or shift-
ing gears
NOTE:
Noises may be caused by differen-
tial assembly, universal joint, wheel
bearing, etc. Find out what is actu-
ally making noise before disassem-
bly.(1) Excessive backlash for hypoid gear. Readjust.
(2) Excessive backlash for differential gear. Replace gear or thrust washer.
(3) Insufficient preload for front or rear bearing. Readjust.
(4) Loose drive pinion nut. Tighten to specified torque.
(5) Loose bolts and nuts such as side bearing
retainer attaching bolt.Tighten to specified torque.
5. Noises when cornering(1) Damaged differential gear. Replace.
(2) Excessive wear or damage of thrust washer. Replace.
(3) Broken pinion mate shaft. Replace.
(4) Seized or damaged side bearing. Replace.
6. Gear noises
NOTE:
Since noises from engine, muffler,
transmission, 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, accelerating, cruising,
and jacking-up all four wheels.
Perform these inspections accord-
ing to condition of trouble. When
listening to noises, shift gears into
four wheel drive and fourth speed
position, trying to pick up only dif-
ferential noise.(1) Improper tooth contact of hypoid gear. Readjust or replace hypoid gear
set.
(2) Improper backlash for 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, scored, or chipped front or rear bearing. Replace.
(7) Seized, scored, or chipped side bearing. Replace.
(8) Vibrating differential carrier. Replace.
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3-4[K200]DIAGNOSTICS
2. Rear Differential