AXLE-REAR
TRUCK SERVICE MANUAL
This failure analysis section covers components of the rear axle and will aid in the diagnosis of prematurely failed parts,
together with an outline of corrective measures to overcome recurrence of the same type of failures.
This publication has been compiled from actual case histories with unretouched photographs in an effort to record
information that will be of assistance in analyzing failures.
Good servicing procedure does not simply imply parts replacement. It requires reassembly of units eliminating the original
cause of failure. The application of mechanical skills and knowledge is the mark of the good mechanic.
CONTENTS
SUBJECT
PAGE
Scored and Scuffed Gear Teeth......................................................................................................................... 58
Scuffed Gear Teeth--Coast Sides Only .............................................................................................................. 59
Fractured Gear Teeth ......................................................................................................................................... 60
Pitted Bevel Pinion Teeth ................................................................................................................................... 61
Fatigue Fracture--Bevel Drive Pinion ................................................................................................................. 62
Overheated Gear Set ......................................................................................................................................... 63
Pitted Planetary Gear Teeth ............................................................................................................................... 64
Shock Fracture ................................................................................................................................................... 65
Worn High Speed Clutch Plate and Differential Bearing Adjuster...................................................................... 66
Worn Support Case Hub .................................................................................................................................... 67
Scoring and Seizure of Spider and Pinoins ........................................................................................................ 68
Fatigue Fracture--Differential Side Gears .......................................................................................................... 69
Fatigue Fracture--Misalignment ......................................................................................................................... 70
Shock Fracture ................................................................................................................................................... 71
Fatigue--At Axle Shaft Flange ............................................................................................................................ 72
Twisted Shaft...................................................................................................................................................... 73
Bent Housing ...................................................................................................................................................... 74
Wear--Inner Bearing Bore .................................................................................................................................. 75
Roller Bearing End Wear.................................................................................................................................... 76
Ball Inner Race Damaged From Circulation of Abrasive Material ...................................................................... 77
56