Transfer Case Assemble

1. Using a press, install the input gear bearing into the front case half.





2. Install the input gear bearing retaining ring into the inside of the front case half.





3. Using a press, install the front output shaft bearing into the front case half.





4. Install the front output shaft bearing retaining ring into the front case half.





5. Using J 42737, install the sector bearing into the rear case half.
- Ensure the bearing seal is positioned outward.
- Ensure the lettering on the bearing is positioned inward.





6. Install the sector into the front case half.





7. Secure the sector shaft (2) to the front case half with the sector retaining ring (1).





8. Install the poppet plunger, poppet spring, poppet bolt o-ring, and poppet bolt into the front case half.
- Tighten the poppet bolt to 20 Nm (15 ft. lbs.).
- Ensure the poppet bolt has a O-ring positioned under the bolt head.
- Apply a light coat of transfer case oil to the mating surface of the poppet bolt o-ring.
- During installation of the poppet plunger, position the sector to align the notch in the sector with the poppet plunger.
- Do not use an impact tool to install the poppet bolt.





9. Ensure the poppet plunger remains in the sector notch during poppet spring and poppet bolt installation.





10. Install the rear retainer bushing into the rear case half.
- Use a hydraulic press to install the rear retainer bushing into the rear case half.
- Install the rear retainer bushing flush with the case half bushing opening.





11. Using J 29162, install the rear output shaft seal into the rear case half.
- Align the seal driver with the notches on the rear output shaft seal.
- Align the rear output seal drain tube with the rear case half drain channel.





12. Using J 33832 and J 8092, install the front output shaft rear bearing into the rear case half.
- Ensure the rounded side of the bearing is install inward toward the rear case half.
- Ensure the lettering side of the bearing is facing outward away from the rear case half.





13. Install the oil fill and drain plugs into the rear case half.
- Tighten the oil fill and drain plugs to 20 Nm (115 ft. lbs.).
- Ensure the oil fill and drain plugs being installed are made of aluminum. A steel plug will cause accelerated corrosion that will destroy the integrity of the magnesium case.
- Do not use an impact tool to install the oil fill and drain plugs.





14. Install the front input gear bearing inside the front input gear.
- Use a press to install the front input gear bearing onto the front input gear.
- Ensure the front input gear bearing is positioned to the bearing stop.





15. Install the front input gear through the front input gear case bearing.





16. Install the front input gear case bearing retaining ring onto the front input gear.
- Use snap-ring pliers to position the retaining ring onto the front input gear.
- During installation of the retaining ring, do not scratch/damage the seal surface area of the front input shaft with the retaining ring.





17. Install the front input gear oil seal into the front case half.
- Use J 33831 to install the front input gear oil seal.
- Ensure the side of the oil seal with the part numbers are positioned outward during oil seal installation.





18. Install the clutch lever (2) and two clutch lever inserts (1) into the front case half.
- Tighten the two clutch lever inserts to 48 Nm (35 ft. lbs.).
- Ensure the clutch lever is free to move after the clutch lever inserts are tightened.
- Ensure the clutch lever roller (3) is resting on the sector.
- The following four steps detail the installation of the clutch lever.





19. Install the two clutch lever inserts into the front case half.
- Do not completely install the clutch lever inserts.
- Screw the clutch lever inserts into the front case half about four or five turns.





20. View of the clutch lever inserts (1) and (2), and front case half (3).





21. Position the clutch lever between the two clutch lever inserts. View of the clutch lever and clutch lever inserts with transparent case half.





22. Tighten the two clutch lever inserts.





23. Install the oil restricter into the mainshaft end.
- Perform this procedure only if the main shaft is new.
- Install the oil restricter into the mainshaft to where the top of the oil restricter is flush with the bottom of the funneled chamber.





24. Install one of the clutch outer drum bearings into the mainshaft.
Use a press to install the bearing.
Install the bearing with the gear side of the bearing facing down.
Ensure the bearing is flush with the bottom of the clutch drum.





25. Install the second clutch outer drum bearing into the mainshaft.
- Use a press to install the bearing.
- Install the bearing with the gear side of the bearing facing down.
- Ensure the second bearing is flush with the top of the clutch drum sprocket flange.





26. Install the clutch drum onto the mainshaft.





27. Install the clutch inner drum onto the mainshaft and clutch drum. The clutch inner drum should rest on top of the clutch outer drum.





28. Install the clutch return spring onto the mainshaft and into the clutch inner drum.
- Ensure the prongs on the clutch return spring are positioned upward and away from the inner clutch drum.
- Ensure the flat side of the clutch return spring is down against the clutch inner drum.





29. Install the inner clutch drum retaining ring.





30. Install the clutch drum flange.
Ensure the clutch drum flange is installed with the ridge side of the flange facing down.
Align the teeth on the clutch drum flange with the slots in the inner clutch drum.
Ensure the lip flange of the clutch drum flange is installed downward.





31. Install a inner clutch plate over the clutch drum flange.





32. Install a outer separator plate over the inner clutch plate.





33. Install a inner clutch plate over the outer separator plate.





34. Install a outer separator plate over the inner clutch plate.
- Continue installing inner clutch plates and outer separator plates until eight of each are installed into the clutch drum.
- After installation of the eight inner clutch plates and the eight outer separator plates, an inner clutch plate should be on top of the plate stack.
- The tabs on all of the separator plates should all be aligned.

35. Shim the the clutch drum pack. Refer to Cleaning and Inspection (Clutch Pack Shim Procedure Clutch Pack Shim Procedure).





36. Using a press, install the inner bearing support into the thrust bearing.
Install the thrust bearing and inner bearing support plate into the outer bearing support plate.





37. Install the thrust bearing, inner and outer bearing support plates onto the main shaft and into the inner clutch drum.
Ensure all of the tabs are aligned.





38. Install the clutch retaining ring onto the mainshaft.





39. Install the mainshaft into the front case half.
- Align the tabs on the inner bearing support with the clutch lever inserts.
- The clutch drum on the mainshaft should align with the front case half.





40. During installation of the mainshaft, align the teeth on the mainshaft with the teeth inside the input gear.





41. Install the front output shaft through the front output shaft bearing and into the front case half.





42. Install the front output shaft retaining ring onto the front output shaft from the outside of the front case half. Do not scratch/damage the oil seal surface of the front output shaft with the front output shaft retaining ring.





43. Using J 33834, install the front output shaft oil seal.





44. position the drive sprocket and driven sprocket onto the chain.





45. Install the chain with the drive and driven sprockets onto the mainshaft and front output shaft.





46. Install the drive and driven sprocket retaining rings onto the mainshaft and front output shaft.





47. Install the gerotor pump retaining ring onto the mainshaft. Ensure the retaining ring is not positioned over the oil hole on the mainshaft.





48. Install the oil pump O-ring into the oil pump inlet hole.





49. Install the oil pump onto the mainshaft.
- Ensure the oil pump seats on the mainshaft flange.
- Ensure the oil pump inlet hole is pointing toward the front output shaft.





50. Install the oil pump pickup tube into the oil pump inlet hole and O-ring.
51. Position the oil pickup tube under the chain.
52. Install the oil screen into the front case half.
53. Secure the screen to the pickup tube with the nylon tube.





54. Install the magnet into the front case half.





55. Install the tone wheel onto the main shaft.
56. Install the rear output bearing onto the main shaft.
57. Install the rear output bearing retaining ring onto the mainshaft.





58. Using a thin coat of clear RTV, install the oil pump retainer tab into the rear case half.





59. Install two case half alignment dowels into the front case half.





60. Install the rear case half onto the front case half.
Apply RTV sealant to the mating surfaces of the front and rear case halves.
During the assembly of the front and rear case halves, the rear output bearing retaining ring must be spread open to allow for the case halves to join.
Do not use an impact gun with case half bolts to drive the case halves together.
Use a rubber mallet to position the case halves together while spreading the rear output bearing retaining ring.

IMPORTANT:
- Do not use steel bolts, studs, or washers to secure the case halves together.
- Any case half bolts, studs, or washers that are worn or broken must be replaced with the correct GM replacement bolts, studs, or washers. A steel bolt, stud, or washer will cause accelerated corrosion that will destroy the integrity of the magnesium case, severe oil leakage, and transfer case malfunction.





61. Install the case half bolts, studs, and washers into the front and rear case halves.
- Tighten the case half bolts and studs to 37 Nm (27 ft. lbs.).
- Ensure the threads on the case half bolts and studs are clean and free of all existing pre-applied thread fastener compounds, corrosion, and debris.
- Apply Loctite(R) PST 565, Loctite(R) PST 242, or the equivalent to the threads of the case half bolts and studs.
- Ensure the bolts and studs are installed and tighten with in ten minutes after the new thread fastener is applied.
- Ensure all case half bolts, studs, washers, and brackets are installed in the same location from where they were removed.
- The transfer case being repaired may or may not have aluminum washers with the case half bolts and studs. Aluminum washers were added during early to mid-year production.





62. Install the case half bolts, studs, and washers into the front and rear case halves.
View of the opposite side of the transfer case.
- Tighten the case half bolts and studs to 37 Nm (27 ft. lbs.).
- Ensure the threads on the case half bolts and studs are clean and free of all existing pre-applied thread fastener compounds, corrosion, and debris.
- Apply Loctite(R) PST 565, Loctite(R) PST 242, or the equivalent to the threads of the case half bolts and studs.
- Ensure the bolts and studs are installed and tighten with in ten minutes after the new thread fastener is applied.





63. Install the two studs securing the transfer case shield mounting bracket to the transfer case.
- Tighten the two studs to 37 Nm (27 ft. lbs.).
- Ensure the threads on the studs are clean and free of all existing pre-applied thread fastener compounds, corrosion, and debris.
- Apply Loctite(R) PST 565, Loctite(R) PST 242, or the equivalent to the threads of the studs.
- Ensure studs are installed and tighten with in ten minutes after the new thread fastener is applied.





64. Install the six input shaft studs into the front case half.
Ensure the threads on the studs are clean and free of all corrosion and debris.
- Tighten the six studs to 37 Nm (27 ft. lbs.).





65. Install the front speed sensor into the front case half.
- Tighten the front speed sensor to 31 Nm (23 ft. lbs.).





66. Install the rear output bearing retaining ring through the retaining ring access hole and onto the mainshaft.
67. Install the rubber plug into the rear case half.





68. Install the two rear speed sensors into the rear case.
- Tighten the rear speed sensors to 31 Nm (23 ft. lbs.).





69. Install the o-ring and transfer case vent tube into the transfer case. Vent tube installation is only necessary if the vent tube is being replaced.





70. Install the motor/encoder gasket and motor/encoder to the transfer case with three bolts.
- Tighten the bolts to 37 Nm (27 ft. lbs.).
- The motor/encoder, sector shaft, and motor/encoder, transfer case bolt mounting holes should all be aligned during installation.
- Ensure the gasket remains aligned with the bolt mounting holes during installation.
71. Remove the fill plug.
72. With the transfer case level, fill the transfer case up to the fill plug with Dexron(R) III, GM P/N 12346143
73. Install the fill plug.
- Tighten the oil fill plug to 20 Nm (15 ft. lbs.).