Preliminary Procedures

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
2. Remove the transfer case shield, if equipped. Refer to Transfer Case Shield Replacement.
3. Remove the rear propeller shaft. Refer to One-Piece Propeller Shaft Replacement or Two-Piece Propeller Shaft Replacement.
4. Remove the front propeller shaft. Refer to Front Propeller Shaft Replacement.
5. Drain the fluid from the transfer case. Refer to Transfer Case Fluid Replacement.
6. Disconnect the electrical connectors and remove the electrical harness from the transfer case.
7. Remove the crossmember. Refer to Transmission Support Crossmember Replacement.
8. Remove the transmission mount. Refer to Transmission Mount Replacement for the 4L60-E/4L65-E/4L70-E transmission, or Transmission Mount Replacement for the 6L50/6L80/6L90 transmission.

1

Transfer Case Nut

Notice: Refer to Fastener Notice in the Preface section.

Tighten
50 N·m (37 lb ft)

2

Transfer Case

Procedure

If installing a new or repaired transfer case, perform the Transfer Case High/Low Clutch reset. Refer to Transfer Case High/Low Clutch Reset.

3

Transfer Case Gasket

Procedure

1. Install a NEW gasket without the use of any type of sealant or lubricant.
2. Apply GM /P/N 12345879 (Canadian P/N 10953511) or equivalent lubricant meeting GM Specification 9985830 to the input shaft splines.