GMC 1989 Light Duty Truck Repair Manual page 166

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4B3-4 / -INCH RING GEAR
• Drive the pinion out of the housing with a
hammer and a soft drift (figure 7).
• Remove the cover (25) and the pinion (15).
19. Collapsable spacer (11) from the pinion.
20. Outer seal (9) and outer pinion bearing (10).
21. Inner bearing (13) and shim (14) from the pinion.
• P ress th e b e a rin g o ff th e p in io n u sin g
J 22912-01 (figure
• Remove the shim.
22. Bearing cups (10) and (13) from the axle housing
using a hammer and a punch.
• WorJ^ the cups out of the housing evenly,
moving the punch back and forth between one
side of the cup and the other.
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CLEANING
Do not steam clean drive parts having ground and
polished surfaces such as gears, bearings, and shafts.
These parts should be cleaned in a suitable solvent. All
parts should be disassembled before cleaning.
Parts should be thoroughly dried immediately after
cleaning. Use soft, clean, lintless rags. Parts may be dried
with compressed air. Do not allow the bearings to spin
while drying them with compressed air.
8
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INSPECTION
It is very important to carefully and thoroughly inspect
all drive unit parts before reassembly.
Thorough inspection of the drive parts for wear or
stress and subsequent replacement of worn parts will
eliminate costly drive component repair after reassembly.
AXLE HOUSING
Inspect
V
• The ca rrier bore for nicks or burrs that would
prevent the outer diameter of the pinion seal from
sealing. Remove any burrs that are found.
• The bearing cup bores for nicks or burrs. Remove
any burrs that are found.
• The housing for cracks. Replace the housing if any
cracks are found.
• The housing for foreign material such as metal
chips, dirt, or rust. Refer to " C lea ning " in this
section.
DIFFERENTIAL
Inspect
I?
• Pinion gear shaft for unusual wear.
• Pinion gear and side gear teeth for wear, cracks,
scoring, and spalling.
• Thrust washers for wear.
• The fit of the differential side gears in the differential
case.
• The fit of the side gears on the axle shafts.
• Differential case for cracks and scoring.
• Replace all worn parts.
PINION AND RING GEAR
Inspect
I?
Pinion and ring gear teeth for cracking, chipping,
scoring, or excessive wear.
Pinion splines for wear.
Pinion flange splines for wear.
The fit of the pinion on the pinion flange.
The sealing surface of the pinion flange for nicks,
burrs, or rough tool marks which would cause
damage to the seals' inside diameter and result in
an oil leak.
Replace all worn or broken parts.
Ring and pinion gears are matched sets and are
both replaced any time a replacement of either is
necessary.
BEARINGS
Inspect
U
Bearings visually and by feel.
The bearings should feel smooth when oiled and
rotated while applying as much hand pressure as
possible.
The large end of the bearing rollers for wear. This is
where tapered roller bearing wear is most evident.
B earing cups for wear, cracks, b rin e llin g and
scoring.
Bearings and cups are only replaced as sets.