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

4C2-2 9 /4-INCH RING GEAR FRONT AXLE
3

INSPECTION

Perform the following checks before disassembling the
axle.
1. Remove the axle cover from the axle and drain the
axle lubricant into a suitable container.
2. Check the ring gear backlash. Refer to " Backlash
Adjustment." 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.
3. Inspect the case for metal chips. Determine where
the metal chips come from, such as a broken gear
or bearing cage.
4. Determine the cause of the axle problem before
disassembly if possible.

DISASSEMBLY

Remove or Disconnect (Figure 1)
Tools Required:
J 24385-01 Differential Housing Spreader
J 29721 Differential Side Bearing Remover
J 29721-70 Side Bearing Adapters
J 8107-3 Side Bearing Puller Plug
J 8614-10 Pinion Flange Holder
• Place the axle in a suitable support.
1. The differential cover bolts (17) and the differential
cover (14) (figure 2).
• Drain the gear lubricant into a proper container.
2. Axle shafts (38). Refer to the proper Light Duty Truck
Service Manual.
3. Bearing cap bolts (19) (figure 3).
4. Bearing caps (18).
• The mating letters are stamped on the caps
and the axle housing. The caps are to be
reassembled exactly as removed.
• Assemble J 24385-01 to the differential housing as
shown in figure 4.
• Assemble the dial indicator as shown in figure 4.
Preset the gage at least 0.50 mm (0.020-inch), and
then rotate the gage housing to zero the dial.
NOTICE: Do not spread the differential carrier
more than 0.38
Over-spreading the carrier can damage or
distort the carrier.
• Spread the carrier while examining the dial
indicator. Do not spread the carrier more than 0.38
mm (0.015-inch).
5. Differential case (22) from the carrier (1) using two
pry bars (figure 5).
6. The spreader J 24385-01 from the carrier (1).
7. Bearing cups (20).
• Mark the cups as left and right, and place
them with the proper bearing caps.
8. Differential side bearings (20) using J 29721, and
J 29721-70 and J 8107-3 (figure 6).

DISASSEMBLY OF AXLE

mm (0 .0 1 5-inch).
• Mark the bearings as left and right, and place
them with the proper bearing caps and cups.
9. Differential shims (21).
• Mark the shims as left or right.
10. Ring gear bolts (23), and discard.
• Place shop towels over the vise jaws. Put the
differential case in the vise (figure 7).
NOTICE: Do not pry the ring gear from the case;
this w ill damage the ring gear and the
differential case.
Ring gear (2) from the differential case using a
11
.
rawhide hammer.
• Ring gear (2) from the vise.
Put the differential case in the vise.
Lock pin (29) from two differential using a hammer
12
.
and a punch (figure 8).
13 Pinion shaft (28) using a hammer and a brass drift
.
(figure 9).
14. Differential pinion gears (24) and thrust washers
(26).
• Rotate the side gears until the pinion gears
are in the opening of the differential (figure
10
).
15. Differential side gears (25) and thrust washers (27).
• Mark the gears and washers as left and right.
Replace the carrier cover (14) using two bolts (17) to
keep the pinion from falling to the floor.
• Drive pinion bearing preload (figure 11).
• Pinion assembly for looseness by moving it
back and fo rth . (Looseness in d ica te s
excessive bearing wear.)
16. Pinion nut (12) and washer (11) using J 8614-01 to
hold the pinion (figure 12).
17. Pinion flange (10) using J 8614-01 (figure 13).
18. Pinion (2) from the carrier using a rawhide hammer
to tap the pinion (figure 14).
19. Carrier cover (14) and the pinion (2).
20. Pinion preload shims (6).
• Keep the shims together on the bench.
21. Pinion seal (9).
22. Pinion outer bearing (7) and oil slinger (8).
23. Bearing cups (3) and (7) from the axle housing using
a hammer or a punch (figure 15).
• Work the cups out of the housing evenly,
moving the punch back and forth between one
side of the cup and the other.
24. Pinion adjusting shims (4) and baffle (5).
• Keep the shims together on the bench.
25. Pinion inner bearing (3) using J 29721 and
J 29721-70 (figure 16).
26. Axle shaft seals.