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FRONT AXLE (4X4)
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4.5.2.1.5 GENERAL SYMPTOMS AND DIAGNOSIS
CONDITION
POSSIBLE CAUSES
Noise in all driving modes
Road and tyres, wheel bearings
Noise changes with type of road surface
Road and tyres
Noise tone lowers with vehicle speed
Tyres
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 dif-
ferential 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, con-
taminated lubricant, bearing preload too high, excessive
gear wear, insufficient ring gear backlash.
Gear teeth broke.
Overloading, erratic clutch operation, wheel pinning, im-
proper adjustment.
Axle gear noise
Insufficient lubricant, incorrect backlash, improper tooth con-
tact, worn / damaged gears.
Axle noise
Insufficient lubricant, improper ring gear and drive pinion
gear adjustment, unmatched ring gear and drive pinion gear
, worn teeth on ring gear or drive pinion gear, loose drive
pinion gear shaft bearings, loose differential bearings, mis-
aligned ring and pinion gear, loose differential bearing cap
screw, worn bearings.