GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C Sierra - 2WD 🢒 Transmission/Transaxle 🢒 Manual Transmission - NV 3500 🢒 Main Shaft Assemble

Tools Required

    • J 6133-A Bearing Race Installer
    • J 22873 Slide Hammer
    • J 36184 Press Tube Adapter
    • J 36373 Input Gear Ball Bearing Installer
    • J 36515 Assembly Pallet
    • J 36515-15 Mainshaft Adapter
    • J 36515-16 Countershaft Adapter
    • J 36850 TRANSJEL Lubricant
    • J 39924-1 Reverse Drag Seal Installer
    • J 39924-2 5th Gear Drag Seal Installer

    Object Number: 4737 Size: SH
  1. Using the J 39924-1 , install the reverse speed gear drag seal.

    2. Object Number: 4735 Size: SH
  2. Install the reverse speed gear needle bearing (1).
  3. Lubricate the reverse speed gear bearing with transmission fluid.
  4. Install the reverse speed gear (2).

    5. Object Number: 761090 Size: SH
  5. Install the 5th/Reverse speed gear synchronizer assembly using a hydraulic press and J 36184 .
    6. 5.1. Align the groove on the 5th/Reverse synchronizer sleeve towards the reverse gear.
    5.2. Ensure the reverse synchronizer blocking ring is aligned to the synchronizer hub.

    Object Number: 7906 Size: SH
  6. Install a new 5th/Reverse synchronizer hub retaining ring.

    7. Object Number: 4739 Size: SH
  7. Install the 5th speed gear needle bearing (1).
  8. Lubricate the bearing with transmission fluid.
  9. Install the synchronizer ring (2).
  10. Install the 5th speed gear (3).

    11. Object Number: 4811 Size: SH
  11. Install the 1st speed gear needle bearing assembly.
  12. Lubricate the bearing with transmission fluid.

    13. Important: The groove on the outside of the synchronizer sleeve must go towards the 2nd speed gear. This prevents gear clash during 1st and 2nd speed gear shifts. The teeth of the sleeve have different angles.


    Object Number: 4740 Size: SH
  13. Install the following components:
    14. 13.1. The 1st speed gear (1)
    13.2. The synchronizer interim ring (2) with the teeth up
    13.3. The reactor cone (3) with the flat side towards 1st gear
    13.4. The blocker ring (4) with the teeth down
    13.5. The synchronizer cone (5) with the flat side down

    Object Number: 761092 Size: SH
  14. Install the 1st/2nd speed gear synchronizer assembly with both synchronizer rings.
    15. 14.1. Manually align and engage the splines of the synchronizer hub with the main shaft splines.
    14.2. Using a hydraulic press, the J 22873 , press the synchronizer hub onto the main shaft.
    14.3. Start the press operation.
             14.3.1. Stop pressing before the tangs engage.
             14.3.2. Lift and rotate the gear.
             14.3.3. Engage the synchronizer ring.
    14.4. Press the synchronizer until seated.
    14.5. Remove all the metal shavings.

    Object Number: 7907 Size: SH
  15. Install a new 1st/2nd gear synchronizer retaining ring.

    16. Object Number: 4815 Size: SH
  16. Install the following 2nd gear synchronizer components:
    17. 16.1. The synchronizer cone with the flat up
    16.2. The blocker ring with the tangs up
    16.3. The reaction cone with the wide flat portion up
    16.4. The interim ring

    Object Number: 4743 Size: SH
  17. Install the 2nd speed gear needle bearing (2).
  18. Lubricate the bearing with transmission fluid.
  19. Install the 2nd speed gear (1).

    20. Ensure that the synchronizer ring gear teeth are positioned toward the 1st gear.


    Object Number: 761095 Size: SH
  20. Install the 2nd speed gear 2 piece thrust washer. Ensure that the dots on the thrust washer are facing up.
  21. Install the retainer ring. Ensure that the retainer ring is installed around the thrust washers.

    22. Object Number: 4745 Size: SH
  22. Install the following components:
    23. 22.1. The 3rd speed gear needle bearing (1)
    22.2. The 3rd speed gear (2)
    22.3. The synchronizer ring (3)

    Object Number: 761097 Size: SH
  23. Install the 3rd/4th speed gear synchronizer assembly with both synchronizer rings. Ensure that the groove in the synchronizer ring faces upward.
    24. 23.1. Manually align and engage the splines of the synchronizer hub with the main shaft splines.
    23.2. Using a hydraulic press, the J 36373 , press the synchronizer hub onto the main shaft.
    23.3. Start the press operation.
             23.3.1. Stop pressing before the tangs engage.
             23.3.2. Lift and rotate the gear.
             23.3.3. Engage the synchronizer ring.
    23.4. Press the synchronizer until seated.
    23.5. Remove all the metal shavings.

    Object Number: 4808 Size: SH
  24. Install a new mainshaft snap ring.

    25. Object Number: 4748 Size: SH
  25. Install the input shaft (1) on the assembly fixture J 36515-15 and J 36515 .
  26. Install the pilot bearing (2) in the input shaft (1).
    27. 26.1. Ensure the small diameter of the bearing is positioned toward the input shaft.
    26.2. Lubricate the pilot bearing with J 36850 .
  27. Install the synchronizer ring (3) on the input shaft (1).
  28. Install the mainshaft assembly (4) onto the input shaft (1).

    29. Object Number: 5224 Size: SH
  29. Install the following parts on the mainshaft and on the assembly fixture J 36515-16 :
    30. 29.1. The countershaft assembly (1)
    29.2. The reverse idler assembly (2)
    29.3. The 1st/2nd speed gear shift fork (3)
    29.4. The 5th/Reverse speed gear shift fork (4)
  30. Install the countershaft bearing on the countershaft.

    31. Use the J 36850 in order to retain the bearing.

    The smaller diameter of the bearing cage is positioned toward the housing.


    Object Number: 4749 Size: SH
  31. If RWD vehicle, install the main shaft rear bearing (2) on the main shaft.
  32. Install a new main shaft rear bearing retaining ring (1).

    33. Object Number: 761093 Size: SH
  33. If RWD vehicle, using J 6133-A , install the reluctor wheel onto the main shaft.