INSPECTION
Remove the filler plug and then check the gear oil. If it is contaminated or deteriorated, replace the gear oil.
Check the gear oil level is up to the bottom part of filler bolt. If the level is low, refill up to the bottom of filler bolt.
Scheme 6
- Filler plug
- Drain plug
Wash all the disassembled parts clean, and examine them for wear, damage, or other defects. Repair or replace defective parts as necessary.
Hypoid driven gear and drive pinion
- If abnormal tooth contact is evident, find out the cause and adjust to give correct tooth contact at assembly. Replace the gear if excessively worn or incapable of adjustment.
- If crack, score, or seizure is evident, replace as a set. Slight damage of tooth can be corrected by oil stone or the like.
Side gear and pinion mate gear
- Replace if crack, score, or other defects are evident on tooth surface.
- Replace if thrust washer contacting surface is worn or seized. Slight damage of the surface can be corrected by oil stone or the like.
Bearing
Replace if seizure, peeling, wear, rust, dragging during rotation, abnormal noise or other defect is evident.
Thrust washers of side gear and pinion mate gear
Replace if seizure, flaw, abnormal wear or other defect is evident.
Oil seal
Replace if deformed or damaged, and at every disassembling.
Differential carrier
Replace if the bearing bores are worn or damaged.
Differential case
Replace if its sliding surfaces are worn or cracked.
Companion flange
Replace if the oil seal lip contacting surfaces have flaws.
Make sure that there is no oil leakage from side oil seal.
If there is any oil leakage, replace the oil seal.
Check the rear differential member for damage, bend, or corrosion.
If damage, bend, or corrosion is excessive, replace the rear differential member.
Check the bushings of rear differential member for cracking, hardening, or damage.
If cracking, hardening, or damage is excessive, replace the rear differential member.
| Symptom or trouble | 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 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 the 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 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 hypoid 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 gears 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 hypoid gear. | Readjust. |
| (2) Excessive backlash for differential gear. | Replace the 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 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 position, 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 carrier. | Replace. |
| 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. |
| 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. |
| NOTE |
|---|
| Noises may be caused by differential assembly, universal joint, wheel bearing, etc. Find out what is actually making noise before disassembly. |
| NOTE |
|---|
| Since noises from 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 position, trying to pick up only differential noise. |
PROBLEM SYMPTOMS CHART