3. Transfer Case Assemble
Transfer Case Assemble^ Tools Required
- J 8092 Universal Handle
- J 36370 Drive Sprocket Needle Bearing Installer
- J 37668-A Seal Installer
- J 42737 Sector Bearing Installer
- J 42738 Seal Installer
- J 43484 Seal Installer
- J 45380 Transfer Case Rear Bushing Remover and Installer
Important: The following service procedure covers light duty, heavy duty, and super duty versions of this transfer case.
When installing the new retaining rings in any of the following service procedures, ensure that the retaining rings are properly seated before proceeding to the next service procedure. Always use NEW retaining rings.
1. Install the adapter studs to 29.5 - 30.5 mm (1.16 - 1.20 inch) in height, if removed.
2. Using the J 8092 (1) and the J 36370 (2), install the front output shaft rear bearing.
3. Using the J 42737, install the shift detent lever shaft bearing.
4. Install the shift detent lever shaft.
5. Install the shift detent lever shaft retaining ring.
Important: When installing the front input gear bearing, ensure that the groove in the input gear bearing is facing up.
6. Install the input gear bearing.
7. Install the input gear bearing inner retaining ring.
8. Install the front output shaft front bearing.
9. Install the front output shaft front bearing inner retaining ring.
10. 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.
11. If removed, install the front output shaft rear bearing race, using a hydraulic press and a suitable driver.
12. Install the front output shaft assembly.
13. Install the front output shaft front bearing outer retaining ring.
14. Install the planetary carrier thrust washer.
15. Using a suitable driver, install the cup plug (1) in the input gear to 54.4 mm (2.10 inch) (a).
16. Using a suitable driver, install the needle bearing (2) in the input gear to 30.7 mm (1.21 inch) (b).
17. Install the input gear in the planetary carrier.
18. Ensure the input gear turns freely. If the input gear does not turn freely, inspect for debris.
19. Install the planetary carrier front thrust washer.
Important: When installing the lock plate, ensure that the letter "E" stamped on the lock plate is facing up.
20. Install the planetary carrier lock plate.
21. Install the retaining ring for the input gear.
22. Install the high/low planetary carrier.
23. Install the outer retaining ring for the input gear bearing.
24. Assemble the high/low shift fork assembly.
25. Install the high/low shift fork on the high/low range collar.
26. Install the high/low range collar with the shift fork to the planetary carrier.
27. Mount the rear output shaft in a soft-jaw vise with the input end up.
28. Install the drive sprocket sleeve on the rear output shaft.
29. Install the drive sprocket front retaining ring.
30. If disassembled, assemble the synchronizer assembly.
30.1. Install the inserts (7) in the hub (6)
30.2. Install the insert springs (5 and 8). Ensure the hooked end of the spring is located in an insert slot.
30.3. Install the synchronizer sleeve (4) on the synchronizer hub (6). The sleeve with the taper and groove end aligns to the shorter side teeth of the hub.
31. Install the synchronizer rings on the rear output shaft. Align the tabs of the outer ring with the slots in the inner ring.
31.1. Install the inner ring
31.2. Install the middle ring
31.3. Install the outer ring
32. Install the synchronizer assembly.
^ The taper or groove end of the synchronizer sleeve faces toward the input end of the rear output shaft.
^ The outer synchronizer ring tabs align to the synchronizer hub.
33. Install the synchronizer retaining ring. Ensure the retaining ring is fully seated in the groove.
34. Install the two/four wheel drive mode shift fork on the synchronizer assembly.
35. Install the shift shaft in the mode shift fork.
Important: Ensure the mode shift fork is installed with the roller side down.
36. Install the clutch gear.
37. Install the shift shaft and the synchronizer assembly with the rear output shaft in the front case half and the high/low range collar.
38. Install the two/four wheel drive synchronizer gear.
^ Ensure to align the middle synchronizer tabs to the gear.
^ Ensure the gear is aligned to the synchronizer sleeve.
Important: When performing the following service procedure, ensure that marks that were used to mark the position of the chain to the relationship of the chain to the sprockets.
39. Install the drive chain on the front output shaft and the rear output shaft assembly.
40. Install the drive sprocket retaining ring.
41. Install the driven sprocket retaining ring.
Important: The super duty version of the NVG 263 transfer case does not use an oil pump seal.
42. Install a NEW O-ring seal for the oil pump pick up tube in the oil pump.
43. Install the oil pump on the rear output shaft.
Important: Install the speed reluctor wheel with the step toward the oil pump assembly.
44. Install the speed reluctor wheel.
Important: The super duty version of the NVG 263 transfer case does not use a speed reluctor wheel retaining ring.
45. Install the speed reluctor wheel retaining ring.
Important: When installing the rear output shaft bearing on the mainshaft, ensure the groove on the rear output shaft bearing is facing up.
46. Install the rear output shaft bearing.
47. Install the rear output shaft bearing retaining ring.
48. Install a new O-ring seal on the shift detent spring bolt.
Notice: Refer to Fastener Notice in Service Precautions.
49. Install the shift detent spring, the plunger, and the bolt.
^ Tighten the poppet bolt to 18 Nm (13 ft. lbs.).
50. Install the magnet.
51. Install a new oil pump O-ring for the oil pump suction pipe in the oil pump.
52. Install the oil pump screen in the front case half.
53. Install the connector on the oil pump screen
54. Install the oil pump suction pipe in the connector.
55. Install the oil pump suction pipe in the oil pump body.
56. Install the shift fork shaft detent spring on the shift shaft.
57. Install the locating pins in the front case half, if removed.
58. Install the oil pump wear retaining clip, only if worn or damaged.
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.
59. Install the locating pins in the front case, if necessary.
60. Apply a 3.175 mm (1/8 inch) bead of RTV sealant GM P/N United States 12345739, GM P/N Canada 10953541 or equivalent to the front case half.
61. Align the outer retaining ring tabs for the rear output shaft bearing with the slot in the rear case half.
62. Install the rear case half to the front case half.
63. Using a pair of snap ring pliers, open the outer retaining ring for the rear output shaft bearing.
Notice: This component is made of magnesium and proper assembly is required to prevent damage. Ensure the magnesium transfer case housings are properly insulated from all external steel components or galvanic corrosion will occur. New nylon coated case bolts and aluminum washers must be used. Use only aluminum fill and drain plugs. Use only aluminum brackets under the case bolts. Ensure new seals are installed that have a rubber insulated outside diameter and have no tears or cuts. Extensive damage will occur if there is galvanic corrosion between the magnesium and steel components.
64. Align the brackets to the proper bolt holes.
65. Install the NEW case half bolts and the aluminum washers.
^ Tighten the case half bolts to 38 Nm (28 ft. lbs.)
66. Install a new rear output shaft bushing, using the J 45380.
66.1. Install the bushing or the finger section of the J 45380.
66.2. Install the finger section to the main body of the J 45380.
66.3. Position the bushing and tool to the case.
66.4. Using a hammer and the J 45380, install the bushing.
Important: When installing the rear output shaft seal, ensure that the drain hole is pointed down.
67. Using the J 37668-A, install the rear output shaft seal to the transfer case.
68. Using the J 43484 (2) and the J 8092 (1), install the front output shaft seal in the transfer case.
69. Using the J 42738, install the input shaft seal to the transfer case.
70. Install the speed sensor in the transfer case.
^ Tighten the speed sensor to 18 Nm (113 ft. lbs.).
71. Install the actuator insulator to the transfer case.
72. Install the encoder motor to the transfer case. Rotate the control actuator lever shaft to align to the encoder motor.
73. Install the mounting bolts for the encoder motor.
^ Tighten the encoder motor mounting bolts, in the sequence shown, to 20 Nm (15 ft. lbs.).
74. Install the vent tube elbow, if damaged.
75. Install the access hole plug in the transfer case.