Tools Required

1. install the oil pump pickup to the pickup tube.
2. Install the pickup tube to the oil pump housing.
3. Install the oil pump pickup to the oil pump housing.
4. Install the retainer to the oil pump housing.
5. Install the oil pump front cover.

Ensure the word TOP faces toward the front of the front case.

6. Assemble the oil pump pins and the oil pump spring.

•	Ensure the flats of the oil pump pins are facing rearward, toward the output end of the shaft.

•	Place the oil pump spring between the two pins.

7. Install the oil pump pin and spring into the oil pump bore on the mainshaft.
8. Lubricate the oil pump housing.

Use Dexron® III automatic transmission fluid or equivalent.

9. Install the oil pump housing onto the mainshaft.

Ensure the oil pump pins ride against the inside of the pump housing.

10. Install the oil pump rear cover.

Ensure the words TOP REAR on the oil pump rear cover is installed toward the rear of the transfer case.

Ensure the word TOP on the front and rear covers are positioned toward the top.

11. Install the oil pump retainer with the tabs toward the front of the transfer case.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

12. Install the oil pump retainer bolts.

Rotate the mainshaft while tightening the bolts in order to prevent the pump from binding.

Tighten
Tighten the bolts to 6 N·m (55 lb in).

13. Ensure the mainshaft turns freely within the oil pump.



14. Install the compression spring to the lockup collar.
15. Install the lockup hub that compresses the compression spring.
16. Install the synchronizer hub snap ring.
17. Using J 37668 , install the rear output shaft seal to the rear bearing retainer.



18. Using the J 8092 and the J 33832 , install the front output bearing to the front case.



19. Install the front output bearing snap ring to the front case.
20. Using J 37668 , install the front output shaft seal to the front case.
21. Using J 8092 andJ 33832 , install the rear output bearing to the rear case.



22. Using J 8092 and J 29169 , install the front input bearing to the front case.



23. Install the front input bearing snap ring to the front case.



24. Install the selector to the front case:
25. Install the detent spring to the front case:
26. Install the detent roller to the front case:
27. Install the selector shaft into the case.
28. Align the selector shaft with the spline on the selector.
29. Connect the retainer clip to the selector shaft.



30. Install the power take off drive gear.

•	Ensure the large flange side of the power take off drive gear is positioned toward the planetary gears.

•	Ensure the input carrier is positioned toward the front case.




31. Install the input carrier snap ring to the input carrier.
32. Using J 37668 , connect the input shaft front oil seal to the front case.



33. Install the annulus gear into the front case.



34. Install the annulus gear snap ring into the front case.



35. Install the range fork and the shaft hub.

•	Align the shift hub to the carrier assembly.

•	Align the shift fork pin to the slot in the selector.

36. Install the shift rail through the range fork and into the boss in the front case.



37. Install the mainshaft and the oil pump into the carrier.

•	Check the one-way orientation of the hub to the shaft.

•	Line up the wide spline of the shaft to the wide shot in the hub.

38. Install the front output shaft to the front output bearing.



39. Install the drive gear onto the mainshaft.
40. With the word "rear" stamped on the side of the driven gear, install the driven gear onto the front output shaft.
41. Using the orientation of the master link as a guide, install the drive chain onto the drive and driven gears.
42. Install the flat washer to the front output shaft.



43. Install the synchronizer and the mode shift fork.

•	Align the synchronizer to the mainshaft drive gear.

•	Align the mode fork to the shift rail.

44. Install the synchronizer hub to the synchronizer.



45. Install the clutch coil housing and the clutch coil housing snap ring to the mainshaft.

The flat side of the snap ring must be positioned toward the clutch coil housing.

46. Install the shift rail spring to the shift rail.
47. Install the clutch coil into the clutch coil housing.



48. Secure the clutch coil with the clutch coil nuts.

Tighten
Tighten the clutch coil nuts to 10 N·m (84 lb in).

49. Position the clutch coil wire through the rear case.
50. Connect the clutch coil wire to the clutch coil.
51. Apply a thin bead of RTV GM P/N 12345739 or equivalent to the front and rear case mating surfaces.
52. Attach the rear case half to the front case half.
53. Install the bracket to the transfer case with the bolt.

Ensure the bracket bolt is installed at the 12 o'clock position on the transfer case.

54. Secure the rear case to the front case with the case bolts.

Tighten
Tighten the case bolts to 41 N·m (30 lb ft).

55. Install the rear output bearing snap ring onto the mainshaft.

Ensure the flat side of the snap ring is install toward the transfer case.

56. Using J 5590 , install the speedometer tone wheel onto the mainshaft.
57. Apply RTV sealer GM P/N 12345739 or the equivalent to the rear bearing retainer sealing surfaces.
58. Install the rear bearing retainer bolts to the rear case.

Tighten
Tighten the retainer bolts to 41 N·m (30 lb ft).




59. Install the rear output yoke, rubber sealing washer, flat washer, and nut onto the rear output shaft.

Tighten
Tighten the nut to 170 N·m (230 lb ft).

60. Install the front output yoke, rubber sealing washer, flat washer, and nut onto the front output shaft.

Tighten
Tighten the nut to 224 N·m (304 lb ft).

61. Install the four wheel drive indicator switch into the front case half.

Tighten
Tighten the switch to 27 N·m (20 lb ft).

62. Secure the speed sensor to the rear bearing retainer with thespeed sensor bolt.

Tighten
Tighten the speed sensor bolt to 16 N·m (12 lb ft).