For 1990-2009 cars

#### Tools Required

• | J 8092 Universal Handle

• | J 37668-A Seal Installer

• | J 42738 Seal Installer

• | J 43484 Seal Installer

### Assembly Procedure

Important: The transfer case housings are magnesium. All steel external components must be isolated from contacting the magnesium or galvanic corrosion will occur. If the fill and drain plugs are to be replaced, they must be made aluminum. All fasteners should be nylon coated and have aluminum washers under the bolt heads. Seals must have rubber on their outside diameters. Brackets used under the case bolts must be aluminum.

Important: After installing any of the retaining rings in the following service procedures, always make sure that the retaining rings are properly seated before proceeding to the next service procedure. If the retaining ring will not seat properly or is damaged, replace the retaining ring.

1. Install the mounting studs to 1.16 inch to 1.20 inch in height (if removed).

Important: When installing the input gear bearing, make sure the printing on the bearing is facing up (toward the technician installing the bearing).

2. Using a press, install the input gear bearing.
3. Install the input gear bearing retaining ring.
4. Install the input gear
5. Install the input gear retaining ring.

Important: When installing the front output shaft bearing, make sure the printing on the bearing is facing up (toward the technician installing the bearing).

6. Using a press, install the front output shaft bearing.
7. Using a press, install the front output shaft.
8. Install the front output shaft retaining ring.
9. Install the viscous coupling.
10. Install the mainshaft assembly.

Important: The blue colored link must be facing up (toward the rear of the vehicle).

11. Install the drive chain and sprockets.
12. Install the driven sprocket retaining ring.
13. Install the carrier retaining ring.

Important: Make sure that the spline engages with both the sprocket and viscous coupling cover. The sun gear shoulder will bottom on the sprocket if installed correctly.

14. Install the sun gear.
15. Install the sun gear thrust washer.

Important: When installing the carrier assembly, a snap should be felt and heard when the carrier is properly seated.

16. Install the carrier assembly.
17. Install the rear output shaft in the annulus gear.
18. Install the annulus gear retaining ring. If the retaining ring is not fully seated and the annulus gear becomes disengaged from the rear output shaft during operation, vehicle could roll when put in park. Also, damage to the viscous coupling could occur.
19. Install the oil pump assembly.
20. Install the tone wheel retaining ring.

Important: The tone wheel should bottom on the retaining ring.

21. Using a press, install the tone wheel.

Important: Ensure that the retaining ring groove on the rear output shaft bearing is facing up (toward the rear of the vehicle).

22. Using a press, install the rear output shaft bearing.
23. Install the rear output shaft bearing retaining ring.
24. Install the rear output shaft assembly.
25. Install the wear clip in the rear case half.

Important: Ensure that the O-ring is in place in the oil pump.

26. Install the oil pump screen and magnet assembly.

Notice: Apply the proper amount of sealant to the flange when assembling the transfer case. Excessive amounts of sealant can plug the oil pump screen, resulting in internal component failure.

Important: Ensure both sealing surfaces of the front and rear case halves are free of dirt, oil, and cleaning solvent.

27. Apply a 3 mm (1/8 in) bead of RTV sealant GM P/N 12345739 or equivalent to the front case half.
28. Align the rear case on the rear output shaft bearing.
29. Insert a pair of snap ring pliers in the slot.
30. Open the outer rear output shaft bearing retaining ring.

Important: Ensure that the rear output shaft bearing retaining ring is seated in the groove properly by prying up on the shaft on the rear output shaft assembly.

31. Lower the rear case on to the rear output shaft bearing.
32. Remove the snap ring pliers.

Important: Ensure that when the rear case is installed, that it is squarely seated on the alignment dowels.

33. Lower the rear case on to the alignment dowels

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.

Important: Ensure that the retaining bracket under the bolt is in line with the speed sensor.

34. Install the transfer case bolts.

Tighten
Tighten the retaining bolts to 31 N·m (23 lb ft)

35. Using the J 42738 , install the input gear seal.

Important: Ensure that the drain hole on the boot of the rear output shaft seal is facing down toward the ground.

36. Using the J 37668-A , install the rear output shaft seal.
37. Using the J 43484 (2) and the J 8092 (1) install the front output shaft seal.
38. Install the transfer case speed sensor.

Tighten
Tighten the transfer case speed sensor to 15 N·m (11 lb ft).

Important: Use only drain and fill plugs that are made from aluminum. Steel or brass plugs are not compatible with the magnesium case.

39. Install the drain plug.

Tighten
Tighten the drain plug to 20 N·m (15 lb ft).

40. Install the fill plug.

Tighten
Tighten the fill plug to 20 N·m (15 lb ft).

41. Install the rubber plug.