Disassembly Of The Rear Axle; Cleaning; Inspection - GMC 1990 Light Truck Repair Manual

10
4B4-2 1 / 2-INCH RING GEAR
DISASSEMBLY OF THE
REAR AXLE
|<"»| Remove or Disconnect (Figure 1)
Tools Required:
J 8107 Side Bearing Remover Plug
J 22888 Differential Side Bearing Remover
J 8614-01 Pinion Flange Remover
J 22912-01 Rear Pinion Cone Remover
• Place the rear axle in a suitable support.
1. Differential cover bolts (25) and the differential cover
(24).
• Drain the gear lubrican t into a proper
container.
2. Axle shafts (47). Refer to the proper service manual.
3. Adjusting nut lock bolts (22).
4. Adjusting nut lock (21).
• Loosen the adjusting nuts (19).
5. Differential bearing cap bolts (28) and washers (27).
6. Differential bearing caps (20).
• Mark the caps and the housing as left and
right.
7. Adjusting nuts (19) and bearing cups (18).
• Mark the nuts and cups as left and right.
8. Differential carrier (34).
9. Differential side bearings using J 23759-A and
J 8107 (figure 2).
• The jaws of J 22888 must pull from beneath
the bearing cone and not the cage.
• Scribe a mark across the differential case.
10. Ring gear bolts (36) and washers (35).
NOTICE: Do not pry the ring gear from the case.
This will damage the ring gear and the
differential case.
11. Ring gear (14) from the differential.
• Drive the ring gear off with a brass drift if
necessary.
12. Case halves.
13. Differential side gears (29) and thrust washers (30).
• Mark the gears and the case halves as left and
right.
14. Differential pinion spider (33).
15. Differential pinion gears (32) and thrust washers (31)
from the spider (33).
Inspect
L*
• Drive pinion bearing preload (figure 3).
• For looseness of the pinion assembly by
moving it back and forth. (Looseness indicates
excessive bearing wear).
16. Pinion assembly cage bolts (7) and washers (8)
(figure 4).
17. Pinion assembly cage (10).
• Tap on the pilot end of the pinion with a
hammer and a brass drift if necessary.
18. Pinion cage shims (11).
• Keep the shims together for measurement
later in the procedure.
• Place the pinion cage in a soft-jawed vice.
19. Pinion flange nut (1) and washer (2) using J 8614-01
to hold the flange (figure 5).
20. Pinion flange using J 8614-01 (figure 6).
21. Pinion (14) from the pinion cage (10).
• Place the cage into an arbor press as shown
in figure 7 and press the pinion from the cage.
Do not let the pinion fall to the floor.
22. Collapsible spacer (12) from the pinion.
23. Inner bearing (13) from the pinion (14).
• Press the bearing from the pinion using
J 22912-01 (figure 8).
24. Pinion seal (5) from the pinion cage.
• Drive the seal from the cage with a hammer
and punch.
25. Front bearing (6) from the cage.
26. Bearing cups from the pinion cage.
27. Pilot bearing (15) from the axle housing using a
hammer and brass drift (figure 9).

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.

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
H O U S I N G
I P Inspect
• The carrier 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 " Cleaning" 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.