General Diagnostic Table: Inspection

PROBLEM SYMPTOM TABLE - DIFFERENTIAL

SYMPTOM OR TROUBLE	POSSIBLE CAUSE	REMEDY
1. Oil Leakage	(1) Worn, scratched. or incorrectly sealed 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 side retainer, or incorrectly fitted O-ring	Thghten the bolts to specified torque. Replace the O-ring
	(4) Loose rear cover attatching bolts or damaged	Tighten the bolts to specified torque. Replace the gasket and apply liquid gasket
	(5) Loose oil filter or drain plug	Retighten and apply liquid gasket
	(6) Wear, damage or incorrectly fitting for 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 braking	Readjust or replace
	(3) Insufficient or improper oil used=	Replace the 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 hyploid gear	Replace
	(2) Insufficient or excessive preload for side, rear or front bearing	Readjust or replace
	(3) Excessive backlash for differential gear	Replace the 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 NOTE: Noises may be caused by differential assembly, universal joint, wheel bearing, etc. Find out what is actually making noise before disassembly	(1) Excessive backlash for hyploid gear	Readjust
	(2) Excessive backlash for differential gear	Readjust or replace
	(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 male shaft	Replace
	(4) Seized or damaged side bearing	Replace
6. Gear noises NOTE: Since noises from the engine, muffler, transmission, propeller shaft, wheel bearings, tires, and body are sometimes mistaken for noises from differential assembly, be careful in checking them. Inspection methods to locate noises include coasting, accelerating, cruising and jacking up all four wheels. Perform these inspections according to condition of trouble. When listening to noises, shift gears into four wheel drive and fourth speed posotion, trying to pick up only differential noise.	(1) Improper tooth contact of hypoid gear	Readjust or replace the hypoid gear set
	(2) Improper backlash for hypoid gear	Readjust
	(3) Scored or chipped teeth of hypoid gear	Replace the hypoid gear set
	(4) Seized hypoid gear	Replace the 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 gear	Replace