HEXA

FRONT AXLE (4X4)

12.2 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

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,

improper adjustment.

Axle gear noise

Insufficient lubricant, incorrect backlash, improper tooth

contact, 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, misaligned ring and pinion gear, loose

differential bearing cap screw, worn bearings.