Tools Required

Notice: Refer to Fastener Notice in the Preface section.




1. If removed, install the transfer case mounting studs.

Tighten
Tighten the mounting studs to 31 N·m (23 lb ft).




2. Attach the J 45759  (2) to the front case half using the adapter studs. All of the assembly procedures can be performed with the case mounted to the J 45759  (2).
3. Install the J 45759  (2) into the J 3289-20  (1) and secure with pivot pin.



4. If removed, apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the threads on the vent.
5. Install the vent.

Tighten
Tighten the vent to 6 N·m (53 lb in).




6. Install the front output shaft rear bearing in the rear case half.

•	Use a hammer and a brass drift only on the outer bearing race.

•	Ensure the bearing is kept square to the bore while installing.





Important: Lubricate all bearings and bearing journals with transfer case fluid during installation.

7. Install the input shaft bushing in the front case half using the J 36373 and a hammer.



8. Install the front bearing for the front output shaft in the front case half.

•	Use a hammer and a brass drift only on the outer bearing race.

•	Ensure the bearing is kept square to the bore while installing.




9. If removed, install the input shaft rear support bearing in the rear output shaft using J 42176  (1) and J 45848  (2).



10. Using the J 22828 and a hydraulic press, install the rear output shaft bearing with the retaining ring groove towards the gear.



11. Using the J 22828 and a hydraulic press, install a NEW speed reluctor wheel.



12. Install a NEW retaining ring for the rear output shaft bearing.



13. Install the rear output shaft in the annulus gear.




Caution: The vehicle could roll while in park if the annulus gear becomes disengaged from the rear output shaft. Always install a new rear output shaft to annulus gear retaining ring. Ensure the rear output shaft retaining ring is fully seated in the annulus gear.

Notice: Damage may occur to the viscous coupling if the retaining ring for the rear output shaft to the annulus gear fails or becomes dislodged during vehicle operation. Always install a new rear output shaft to annulus gear retaining ring. Ensure the rear output shaft retaining ring is fully seated in the annulus gear.

14. Install a NEW annulus gear retaining ring.




Important: Depending on the build date of the transfer case, it may have a rear output shaft bearing with or without a retaining ring groove. In early build transfer cases, the retaining ring (1) for the rear output shaft bearing was in front of the bearing (2). In later build transfer cases, the retaining ring (3) was moved rearward 5 mm (0.197 in) in the case. The bearings (4) have a groove and the retaining ring is installed in the groove. The service bearings will all have the retaining ring groove, work in both the early build and later build transfer cases. When servicing an early build transfer case with the groove bearing, ensure the retaining ring is installed in front of the bearing and not in the groove.

15. Install the rear output shaft in the rear case.

•	Spread the rear output shaft rear bearing outer retaining ring.

•	Using a soft-face hammer, tap on the rear output shaft.




16. Install the input shaft in the front case.



17. Install the viscous coupling on the sun gear.



18. Install the drive gear on the sun gear.



19. Using a hammer with the J 45540  (2) and the J 5590  (1), install the bearing on the sun gear. Ensure the bearing is fully seated against the drive gear.



20. Install the sun gear, with the drive gear and the viscous coupling, on the input gear.



21. If it is a new shaft, or if the cup plug was removed, install the cup plug in the front output shaft using a suitable driver. Install the cup plug 1 mm (0.039 in) from flush with the end of the shaft.




Important: Ensure to align the marks of the drive chain and sprockets, if using the chain and sprockets again.

22. Install the drive chain on the drive sprocket.

•	The blue link on the chain faces up.

•	Align the chain, if using it again, with the alignment marks made during disassembly.




23. Install the driven sprocket and the chain.



24. Install the front output shaft in the driven sprocket and the bearing.



25. Lubricate the sun gear thrust washer with J 36850 or equivalent.
26. Install the sun gear thrust washer.



27. Install the planetary carrier assembly.



28. Lubricate the sun gear thrust washer with J 36850 or equivalent.
29. Install the planetary carrier thrust washer.




Important: 

•	Ensure that both the sealing surfaces on the front and rear case halves are free of dirt, oil, and cleaning solvent.

•	Ensure the locating pins are installed in the front case half.

30. Install the locating pins in the front case, if necessary.
31. Apply a 3.175 mm (1/8 in) bead of RTV Sealant GM P/N 12345739 (Canadian P/N 10953541) or equivalent to the mating surfaces of the front case half.



32. Lower the rear case half into place.



33. Install the case bolts, the washers, and the brackets.

Tighten
Tighten the case bolts to 21 N·m (15 lb ft).




34. Using the J 45756 , install the rear output shaft seal.



35. Install the vehicle speed sensor with a NEW O-ring seal.

Tighten
Tighten the speed sensor to 17 N·m (13 lb ft).




36. Apply pipe sealant GM P/N 12346004 (Canadian P/N 10953480) to the threads on the drain plug and fill plug.
37. Install the drain plug and the fill plug.

Tighten
Tighten the drain plug and fill plug to 25 N·m (18 lb ft).




38. Using the J 43484  (2) and the J 8092  (1), install the front output shaft seal.



39. Using the J 45758 , install the front input shaft seal.
40. Remove the transfer case from the J 45759 .