GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2002 🢒 TrailBlazer - 4WD 🢒 Transmission/Transaxle 🢒 Manual Transmission - NV 3500 🢒 Main Shaft Disassemble

Tools Required

    • J 21427-A Speedometer Gear Puller Adapter
    • J 22912-B Split Plate Bearing Puller
    • J 24420-C Harmonic Balancer Puller

    Object Number: 4800 Size: SH
  1. If RWD vehicle, remove the main shaft bearing retainer.

    2. Object Number: 4801 Size: SH
  2. Remove the following components from the mainshaft assembly:
    3. • The 2 shift forks (1)
    • The reverse idler gear (2)
    • The countershaft rear bearing (4)
    • The countershaft (3)

    Object Number: 736019 Size: SH
  3. If RWD vehicle, using the J 21427-A  (2) and the J 24420-C  (1), remove the speed sensor reluctor wheel from the rear of the main shaft.

    4. Do not reuse the reluctor wheel after removal.


    Object Number: 4803 Size: SH
  4. If RWD vehicle, remove the mainshaft rear bearing retaining ring (1) and the mainshaft rear bearing (2).

    5. Object Number: 4804 Size: SH
  5. Remove the mainshaft assembly from the input shaft.

    6. Important: Leave the synchronizer ring on the 3rd/4th synchronizer assembly to prevent the synchronizer detent balls from popping out.

  6. Remove the 4th gear synchronizer blocking ring and put on the 4th gear synchronizer assembly.
  7. Remove the main shaft front bearing from the input shaft.

    8. Object Number: 4808 Size: SH
  8. Remove the 3rd/4th gear synchronizer retaining ring.

    9. Object Number: 4810 Size: SH
  9. Scribe an alignment mark on the synchronizer hub and the synchronizer sleeve in order to properly reassemble the synchronizer hub assembly.

    10. Object Number: 38500 Size: SH

    Important: When removing the synchronizer hubs use the J 22912-B under the gear for that synchronizer and not the synchronizer sleeve. Do not separate the synchronizer hub from the synchronizer sleeves. Leave the synchronizer rings with the synchronize assembly to prevent the synchronizer detent balls from popping out.

  10. Using a hydraulic press and the J 22912-B remove the 3rd/4th speed gear synchronizer hub assembly, the third speed gear and the synchronizer rings.
  11. Remove the synchronizer assembly from the third gear.

    12. Object Number: 4745 Size: SH
  12. Remove the 3rd speed gear needle bearing assembly (1).

    13. Object Number: 761095 Size: SH
  13. Remove the following components:
    14. 13.1. The 2nd speed gear 2 piece thrust washer
    13.2. The retainer ring

    Object Number: 4743 Size: SH
  14. Remove the following components:
    15. 14.1. The 2nd speed gear (1)
    14.2. The 2nd speed gear needle bearing assembly (2)

    Object Number: 7907 Size: SH
  15. Remove the 1st/2nd gear synchronizer retaining ring from the main shaft.

    16. Object Number: 4815 Size: SH
  16. Remove the following components for the 2nd gear synchronizer:
    17. 16.1. The synchronizer cone
    16.2. The blocker ring
    16.3. The reaction cone
    16.4. The interim ring

    Object Number: 626287 Size: SH
  17. Scribe an alignment mark on the synchronizer hub and the synchronizer sleeve in order to properly reassemble the synchronizer hub assembly.

    18. Important: When removing the synchronizer hubs use the J 22912-B under the gear for that synchronizer and not the synchronizer sleeve. Do not separate the synchronizer hub from the synchronizer sleeves. Leave the synchronizer rings with the synchronize assembly to prevent the synchronizer detent balls from popping out.

  18. Using a hydraulic press and the J 22912-B remove the 1st/2nd speed gear synchronizer hub and the 1st speed gear.

    19. Object Number: 4740 Size: SH
  19. Remove the following components:
    20. 19.1. The synchronizer cone (5)
    19.2. The blocker ring (4)
    19.3. The reactor cone (3)
    19.4. The synchronizer interim ring (2)
    19.5. The 1st speed gear (1)

    Object Number: 4811 Size: SH
  20. Remove the 1st speed gear needle bearing assembly.

    21. Object Number: 4739 Size: SH
  21. Turn the mainshaft over to work on the output end.
  22. Remove the following components:
    23. 22.1. The 5th speed gear (3)
    22.2. The 5th speed gear needle bearing assembly (1). The needle bearing is split in order to remove it over the collar.

    Object Number: 7906 Size: SH
  23. Remove the retaining ring for the 5th/Reverse synchronizer hub from the mainshaft.

    24. Object Number: 626289 Size: SH
  24. Scribe an alignment mark on the synchronizer hub and the synchronizer sleeve in order to properly reassemble the synchronizer hub assembly.

    25. Important: When removing the synchronizer hubs use the J 22912-B under the gear for that synchronizer and not the synchronizer sleeve. Do not separate the synchronizer hub from the synchronizer sleeves. Leave the synchronizer rings with the synchronize assembly to prevent the synchronizer detent balls from popping out.

  25. Using a hydraulic press and the J 22912-B remove the 5th/Reverse speed gear synchronizer assembly and the reverse speed gear.

    26. Object Number: 4735 Size: SH
  26. Remove the reverse speed gear needle bearing assembly (1).

    27. Object Number: 626291 Size: SH
  27. Remove the reverse speed gear drag seal.