GMC S Series 1994, Repair Manual

Page: 260 / 919

GENERAL DESCRIPTION
The front axle on the all wheel drive model uses a
full-time four-wheel drive system, with no disengage­
ment feature.
The axle uses a conventional ring and pinion to trans­
mit the driving force to the wheels. The gear set trans­
fers the driving force at a 90-degree angle from the
propeller shaft to the axle shafts.
The pinion gear is supported by two tapered roller
bearings. The pinion depth is set by a shim pack locat­
ed between the gear end of the pinion and the roller
bearing pressed on the pinion. The pinion bearing
preload is set by crushing a collapsible spacer between
the pinion bearings in the axle housing.
DISASSEMBLY
The ring gear bolts to the differential case with left
hand thread bolts.
The differential case is supported in the axle housing
by two tapered roller bearings. The differential and ring
gears are located in relationship to the pinion by thread­
ed adjusters.
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 while turning
and premature wear on internal axle parts.
The axle identification code is stamped on the top of
the carrier case, along the the machined face.
OF THE AXLE
IN SPEC TIO N
Perform the following checks before disassembling
the axle.
1. Remove the cover from the axle and drain the
lubricant.
2. Check the ring gear backlash. Refer to “ Backlash
A djustm ent.” This inform ation can be used to
determine the cause of the axle problem. It will
also help when setting up the shim packs for locat­
ing and preloading the differential case.
3. Inspect the case and oil for metal chips. Determine
where the metal chips came from, such as a bro­
ken gear or bearing cage.
4. Determine the cause of the axle problem before
disassembly if possible.
DISASSEMBLY
*
Disassemble (Figures 1 through 14)
Tools Required:
J 2619 Slide Hammer
J 8614-01 Pinion Flange Remover
J 21551 Bearing Remover
J 22912-01 Pinion Bearing Cone Remover
J 29307 Slide Hammer
J 33791 Bushing Remover
J 33792 Side Bearing Adjuster Wrench
J 33837 Pinion Bearing Cup Remover Kit
J 29369-2 Countershaft Roller Bearing Remover
1. Shaft (1) with deflector (2) and retaining ring (8).
• Strike the inside of the shaft flange with a
soft-faced hammer to dislodge the shaft. Use
care in pulling the splined shaft through the seal
diameter to avoid cutting the seal.
2. Bolts (6).
3. Tube (5).
4. Right seal (3) and bearing (4), using J 29369-2 and
J 29307 (figure 3).
5. Shaft (59), and deflector (2).
• Use J 2619-01 and J 21579 to pull the output
shaft from the carrier (figure 4).
6. Bolts (58) and cover (57).
7. Left seal (3).
8. Bolts (28).
9. Separate the carrier case (29).
1. Shaft 31. Insert 45. Washer
2. Deflector 32. Sleeve 46. Nut
3. Seal
33. Side Bearing 47. Plug
4. Bearing 34. Bolt 48. Bushing
5. Tube 35. Differential Case 49. Vent Hose
6. Bolt 36. Bolt 50. Vent
8. Retaining Ring
37. Ring and Pinion
51. Fitting
18. Bolt
Gears 52. Shaft
19. Lock 38. Shim 53. Thrust Washer
25. Plug 39. Bearing
54. Side Gear
26. Washer 40. Spacer 55. Thrust Washer
27. Pin 41. Bearing 56. Differential Pinion
28. Bolt
42. Seal Gear
29. Carrier Case
43. Deflector
57. Cover
30. Bearing
44. Flange
58. Bolt
59. Shaft
F7476