1059 / 1906
REAR AXLE
10
13.2 GENERAL SYMPTOMS AND DIAGNOSIS
Most drive axle problems fall into the categories of noise, vibration, leaks and failure to transmit power.
Problem diagnosis normally beings with the customer’s complaint, which should include an exact description
of the type of noise or Vibration and when it occurs. This is followed up by a road test over various types of
road surfaces through the speed where the complaint occurs. It should be remembered that some sound will
appear to come from locations other than the real source of the problem. Sound in drive shaft, exhaust
system and body floor pan can do this, making it more difficult to locate the problem source.
CONDITION
POSSIBLE CAUSES
Noise in all driving modes
Road and tires, wheel bearings.
Noise changes with type of road surface
Road and tires.
Noise tone lowers with vehicle speed
Tires.
Noise louder on turn
Differential pinion and side gears, axle wheel
bearings.
Noise in one or more driving modes
Ring and pinion gears.
Clunk on change of speed or direction of power flow
Worn differential shaft or thrust washers; worn U-
joints.
Wheel noise
Wheel loose, faulty or bad wheel bearing.
Vibration
Damaged drive shaft, missing drive shaft balance
weight, worn or out-of-balance wheels lug nuts,
worn U- joint, loose spring U- bolts, loose / broken
spring, damage axle shaft bearing, loose pinion
gear nut, excessive pinion yoke run out, bent axle
shaft.
Differential gears scored
Insufficient lubrication, improper grade of lubricant,
lubricant contamination, excessive spinning of
wheel.
Loss of lubricant
Lubricant level too high, worn axle shaft seals,
cracked differential housing, worn drive pinion gear
shaft seal, scored and worn yoke, axle cover not
properly sealed, plugged vent or vent tube.
Axle overheating
Lubricant level too low, incorrect grade of lubricant,
contaminated lubricant, bearing preload too high,
excessive gear wear, insufficient ring gear
backlash.
Gear teeth broke.
Overloading, erratic clutch operation, wheel pinning,