GMC T Series 1994 Repair Manual page 164

The differential allows the wheels to turn at different
rates of speed while the axle continues to transmit the
driving force. This prevents tire scuffing on turns and
premature wear on internal axle parts.
The axle is sealed with a pinion seal, a gasket at
each axle shaft end, and a gasket between the cover
and axle housing.
All corporate rear axles are identified by the alphabet­
ic broadcast code on the right axle tube near the carri­
er. The carrier cover does not have a drain plug.
CHECKING THE AXLE
BEFORE DISASSEMBLY
I?
Inspect
Remove the axle cover and drain the axle lubricant.
1. Ring gear backlash. Refer to " Backlash Adjust­
ment." This information can be used to determine
the cause of the axle problem. It will also help
when setting up the shim packs for locating and
preloading the differential case.
2. Case for metal chips and shavings. Determine
where these chips and shavings came from; such
as a broken gear or bearing cage.
Determine the cause of the axle problem before dis­
assembly if possible.
DISASSEMBLY OF THE
REAR AXLE
«--► Remove or Disconnect (Figures 1 through 9)
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
J 22888-20 Universal Puller
* Place the axle in a suitable support.
1. Cover bolts (25) and cover (24).
• Drain the gear lubricant.
2. Outer axle shaft bolts (46).
3. Axle shafts (47).
4. Adjusting nut lock bolts (22).
5. Adjusting nut lock (21).
• Loosen the adjusting nuts (19).
6. Bearing cap bolts (28) and washers (27).
7. Bearing caps (20).
• Mark the caps and the housing as left and right.
8. Adjusting nuts (19) and bearing cups (18).
• Mark the nuts and cups as left and right.
9. Differential case (34).
10. Bearings using J 22888-20 (figure 2).
A. The jaws of J 22888-20 must pull from beneath
the bearing cone and not the cage.
B. Scribe a mark across the differential case.
11. 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.
12. Ring gear (14) from the differential.
• Drive the ring gear off with a brass drift if nec­
essary.
13. Side gears (29) and thrust washers (30).
• Mark the gears and the case halves as left and
right.
14. Pinion spider (33).
15. Pinion gears (32) and thrust washers (31) from the
spider (33).
L*
Inspect
• Drive pinion bearing preload and record
(figure 3).
• For looseness of the pinion assembly by mov­
ing it back and forth. Looseness indicates
excessive bearing wear.
16. Pinion assembly cage bolts (7) and washers (8).
17. Pinion cage (10).
• Tap on the pilot end of the pinion with a ham­
mer and brass drift if necessary.
18. Pinion cage shims (11).
A. Keep the shims together for measurement later
in this procedure.
B. Place the pinion cage in a soft-jawed vise.
19. Pinion flang e nut (1) and w asher (2) using
J 8614-01 to hold the flange (figure 4).
20. Pinion flange using J 8614-01 (figure 5).
21. Pinion (14) from the pinion cage (10).
• Place the cage into an arbor press as shown in
figure 6 and press the pinion from the cage. Do
not let the pinion fall.
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 7).
24. Pinion seal (5) from the cage.
• Drive the seal from the cage with a hammer
and punch.
25. Front bearing (6) from the cage.
26. Bearing cups from the cage.
27. Pilot bearing (15) from the axle housing using a
hammer and brass drift (figure 8).
CLEANING
Do not steam clean drive parts that have ground and
polished surfaces such as gears, bearings, and shafts.
All parts should be disassembled before cleaning.
These parts should be cleaned in a suitable solvent.
Parts should be thoroughly dried immediately after
cleaning. Use soft, clean, lintless rags. Parts may be
dried with compressed air. Do not allow bearings to spin
while drying them with compressed air.
INSPECTION
It is critical to carefully and thoroughly inspect all
drive unit parts before reassembly.
Thorough inspection of drive parts for wear or stress
and subsequent replacement of worn parts will elimi­
nate costly drive component repair after reassembly.