Tools Required

1. Place a pan under the differential assembly.
2. Remove the fill plug and drain plug from differential carrier.
3. Remove the differential from the vehicle. Refer to Differential Carrier Assembly Replacement .
4. Remove the 4 coupling cover bolts.
5. Remove the coupling cover from the differential assembly.
6. Remove the washer and spacer from the differential assembly.



7. Install the J 8001 against the a ring gear tooth.
8. Hold the pinion gear stationary.
9. Using J 35405  (1), move the ring gear back and forth as far as it will travel without turning the pinion gear.

Important: Check the differential backlash at 3 different positions on the ring gear to obtain an accurate reading.

10. Observe the J 8001 while moving the ring gear as previously described. Differential backlash should be within 0.10-0.15 mm (0.0039-0.0059 in).



11. Using a torque wrench (1) and J 46004 , measure and record the drive pinion starting preload. Preload should be between 0.4-0.7 N·m (3-6 lb in).



12. Remove the differential carrier side oil seals using the J 29369-2  (1) and the J 23907  (2).



13. Using a hammer and punch, unstake the drive pinion nut.
14. Using J 46004 and J 46002 , remove the pinion nut.
15. Remove the differential carrier front oil seal using the J 22888-20A .
16. Remove the front bearing from the drive pinion.



17. Remove the vent hose from the differential carrier.



18. Place reference marks (1) on the elbows and differential carrier.
19. Remove the 2 elbows using a screwdriver.
20. Remove the 10 differential cover bolts.



21. Using a brass drift and a hammer, remove the differential cover from the differential carrier.
22. Remove the differential case from the differential carrier.
23. Remove the drive pinion and sleeve from the differential carrier.



24. Remove the drive pinion rear bearing from drive pinion using J 22912-B  (1) and a press.



25. Remove the differential case side bearings from the differential case using J 22912-B  (1) and a press.



26. Place a reference mark (1) on the ring gear and differential case.
27. Remove the 10 ring gear retaining bolts.
28. Using a soft faced hammer, tap the ring gear to remove it from the differential case.



29. Use a punch and a hammer in order to remove the pinion shaft roll pin from the differential case.
30. Remove the following components from the differential case:

•	The pinion shaft

•	The pinion gears

•	The pinion washers

•	The differential side gears

•	The side gear thrust washers

31. Clean all the components thoroughly with clean solvent. Dry the components.
32. Inspect all of the gears for the following conditions. Replace as necessary:

•

Cracks

•	Chipped teeth

•	Broken teeth

•	Other damage

33. Inspect the differential side bearing surfaces. Replace as necessary:

•

Roughness

•	Excessive wear

34. Inspect the differential case gear and bearing surfaces for cracks and blue discoloration. These conditions indicate overheating or other damage. Replace as necessary.

1. Install the following components into the differential carrier:

•	The side gear thrust washers

•	The differential side gears

•	The pinion gear thrust washers

•	The pinion gears

•	The pinion shaft




2. Use a J 8001 in order to measure the differential side gear backlash.

2.1.	Place the J 8001 plunger between the teeth of the left side gear .

2.2.	Hold one pinion gear against the differential case, then move the side gear up and down while observing the J 8001 .

2.3.	The standard differential side gear backlash should be between 0.05-0.20 mm (0.002-0.0079 in).

2.4.	If the differential side gear backlash is not between 0.05-0.20 mm (0.002-0.0079 in), replace the side gear thrust washers with different thicknesses in order to obtain the proper backlash. Refer to Spacer and Shim Specifications .




3. Use a standard drift punch and hammer in order to install the pinion shaft roll pin into the differential carrier and the pinion shaft.
4. Stake the outside of the differential case roll pin hole using a hammer and chisel.



5. Heat the ring gear in boiling water (1).
6. Clean the contact surfaces of the differential case and the ring gear.
7. Carefully remove the ring gear from the boiling water.
8. After the moisture as completely evaporated, quickly install the ring gear on the differential case.



9. Align the reference marks (1) on the differential case and the ring gear.
10. Temporarily install 10 new bolts.

Notice: Refer to Fastener Notice in the Preface section.

11. Allow the ring gear to cool, then tighten the bolts in a star pattern.

Tighten
Tighten the ring gear bolts to 78 N·m (58 lb ft).

12. Install the differential case side bearings using a press.
13. Install the drive pinion rear bearing shim that was removed in disassembly.



14. Install the drive pinion rear bearing (1) using a press.
15. Temporarily install the drive pinion and front bearing.
16. Lightly coat the drive pinion threads with multi-purpose grease.
17. Temporarily adjust the drive pinion preload by tightening the pinion nut.

Tighten
Tighten the pinion nut to no more than 223 N·m (164 lb ft).




18. Measure and record the pinion preload using a torque wrench (1) and J 46004 .

•	Starting drive pinion preload with a new set of bearings should be 0.69-1.27 N·m (6-11 lb in).

•	Starting drive pinion preload with a reused set of bearings should be 0.39-0.69 N·m (3-6 lb in).

19. Temporarily install the differential case into the differential carrier.
20. Temporarily install the differential side cover.



21. Measure the ring gear backlash using the J 8001 and J 35405 .
22. Ring gear backlash should be between 0.10-0.15 mm (0.0039-0.059 in).

Important: If the backlash measurement is not within the specifications given, increase or decrease the thickness of the shims on both sides in equal amounts. Refer to Spacer and Shim Specifications .

•	When the backlash measurement is smaller than the specified value, select a thicker shim for the right side and a thinner shim for the left side.

•	When the backlash measurement is larger than the specified value, select a thinner shim for the right side and a thicker shim for the left side.




23. Measure the differential total preload. This measurement should be the drive pinion preload recorded in the previous step plus 0.3-0.5 N·m (2.6-4.3 lb in).

Adjust total preload by changing the right-hand shim thickness.

24. Remove the 10 differential side cover bolts.
25. Remove the differential side cover from the differential carrier.
26. Remove the differential case from the differential carrier.
27. Coat the ring gear teeth with Gear Marking Compound GM P/N 1052351 (Canadian P/N 10953497).
28. Temporarily install the differential case in the differential carrier.
29. Temporarily install the differential side cover to the differential carrier.
30. Install the 10 differential side cover bolts.
31. Rotate the drive pinion several times.
32. Remove the 10 bolts and the differential side cover.
33. Check the ring gear tooth contact pattern.

Important: When changing the thickness of the side gear shim, adjust the drive pinion preload, ring gear backlash and total preload before adjusting the ring gear tooth contact pattern.

34. Adjust the contact pattern as necessary.
35. Remove the differential case from the differential carrier.
36. Remove the drive pinion from the differential carrier.
37. Install a new bearing spacer and the oil slinger on the drive pinion.
38. Install the drive pinion.
39. Using J 46002 and J 46004 , install the drive pinion nut.

Tighten
Adjust the drive pinion preload by tightening the nut NO MORE THAN 223 N·m (164 lb ft).

40. Check the pinion preload using a torque wrench (1) and J 46004 .

•	Starting drive pinion preload with a new set of bearings should be 0.69-1.27 N·m (6-11 lb in).

•	Starting drive pinion preload with a reused set of bearings should be 0.39-0.69 N·m (3-6 lb in).

•	If the preload is greater than specified, replace the collapsible spacer.

•	If the preload is less than specified, tighten the drive pinion nut an additional 13 N·m (9 lb ft) of torque at a time until a maximum of 245 N·m (181 lb ft) is reached.

41. Clean the mating surfaces of the differential side cover and the differential carrier.
42. Install the differential case in the differential carrier.




Important: Do not add gear oil or drive the vehicle immediately after cover installation. Allow silicone to cure for 1 hour or more. Avoid rapid acceleration or deceleration for 12 hours or more.

43. Apply a 2-3 mm (0.08-0.12 in) bead of Red Silicone Sealant GM P/N 1052366 to the differential side cover. Begin and end the application in area (a).
44. Install the differential side cover on the differential carrier.
45. Install the 10 side cover bolts.

Tighten
Tighten the 10 bolts to 42 N·m (31 lb ft).

46. Check the ring gear backlash, then check the total preload.



47. Align the elbow reference marks, then install elbows into the differential carrier.
48. Install the breather hose.
49. Install the new front oil seal.
50. Install the side gear oil seals.
51. Install the coupling into the coupling cover, then install the assembly on the differential carrier.
52. Install the 4 coupling cover bolts.

Tighten
Tighten the bolts to 19 N·m (14 lb ft).

53. Install the differential carrier into the vehicle. Refer to Differential Carrier Assembly Replacement .
54. Install the drain plug.

Tighten
Tighten the drain plug to 39 N·m (29 lb ft).

55. Fill the differential carrier with 0.5 liters (1.05 pints) of GL-5 80W-90W gear oil or equivalent.
56. Install the fill plug.

Tighten
Tighten the fill plug to 39 N·m (29 lb ft).