GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 22873 Slide Hammer
    • J 36183 Input Shaft Press Tube With Cap
    • J 36184 Input Shaft Press Tube Reducer
    • J 36511 Oil Fill Plug Hex Bit (17 mm)
    • J 41663 Assembly Pallet Main Shaft Adapter

    Object Number: 143340  Size: SH

    Notice: All synchronizer blocking rings found inside the transmission are interchangeable except those used on the reverse synchronizer.

    Important: Install the synchronizer sleeves with the offset teeth toward the second, third and fifth gear.

    Sleeves are identified with the following marks:

       • First and second: One groove on the outer diameter (OD) of the first gear
       • Third and fourth: Two grooves on the outer diameter (OD) of the third gear
       • Fifth and reverse: Two grooves on the outer diameter (OD) of the fifth gear
            One groove on the reverse gear

    Important: Lubricate all components during assembly.

    Use lubricant Synchromesh Transmission Fluid with friction modifier or equivalent.

  1. Position the following components onto the end of the output shaft:
  2. 1.1. The reverse gear
    1.2. The synchronizer blocking ring
    1.3. The fifth reverse synchronizer

    Use the J 22873 in order to install the fifth reverse synchronizer.

    1.4. The synchronizer blocking ring
    1.5. The snap ring
    1.6. The fifth gear

    Object Number: 143339  Size: SH
  3. Use the J 22873 in order to install the ball bearing.
  4. Install the snap ring to the mainshaft.
  5. Position the speed sensor gear down the main shaft two inches from the ball bearing.
  6. Use the J 22873 in order to position the ball bearing.

  7. Object Number: 144188  Size: SH
  8. Position the following components onto the input end of the main shaft:
  9. (Make sure that the scribed hub is correctly aligned.)

    6.1. The first gear
    6.2. The inner cone
    6.3. The middle cone
    6.4. The two synchronizer blocking rings
    6.5. The first and second gear synchronizer
    6.6. The first and second gear synchronizer hub

    Align the synchronizer rings with the keys on the first and second gear synchronizer. One synchronizer ring should be on each side of the synchronizer and the hub.

  10. Position the snap ring into the slot on the main shaft.

  11. Object Number: 144179  Size: SH
  12. Position the following components onto the input end of the main shaft:
  13. 8.1. The middle cone
    8.2. The inner cone
    8.3. The second gear
    8.4. The two piece split washer with the retainer ring.

    Object Number: 144172  Size: SH
  14. Install the third gear.
  15. Use the J 22873 in order to position the following components:
  16. 10.1. Two synchronizer blocking rings
    10.2. The third and fourth gear synchronizer
    10.3. The third and fourth gear synchronizer hub
  17. Align the synchronizer blocking rings with the keys on the third and fourth gear synchronizer.
  18. Position the snap ring.

  19. Object Number: 143341  Size: SH
  20. Position the following components onto the input end of the main shaft:
  21. 13.1. The pocket bearing
    13.2. The input shaft
  22. Turn over the main shaft.
  23. Reposition the main shaft onto the J 41663 .

  24. Press the counter shaft rear bearing onto the counter shaft.
  25. Press the snap ring on to the counter shaft.

  26. Object Number: 144206  Size: SH
  27. Position the counter shaft onto the J 41663 .
  28. Important: 

       • When assembling the reverse idler gear, make sure that the chamfer on the segment and the collar are facing up, toward the rear.
       • Make sure that the groove on the idler gear is toward the collar.

  29. Position the following components onto the reverse idler shaft:
  30. 18.1. The two O-rings
    18.2. The caged roller bearings
    18.3. The reverse idler gear
    18.4. The idler shaft support collar
  31. Position the reverse idler shaft assembly onto the J 41663 .

  32. Object Number: 144202  Size: SH
  33. Position the output shaft bearing retainer onto the mainshaft and the countershaft.
  34. Make sure that the output shaft bearing retainer is positioned behind the ball bearings on the mainshaft and the countershaft.
  35. Make sure that the fork end of the output shaft bearing retainer is positioned under the counter shaft ball bearing.
  36. Make sure that the hook end of the output shaft bearing retainer is positioned under the main shaft ball bearing.

  37. Object Number: 144206  Size: SH
  38. Install the fifth/reverse shift fork onto the first/second shift fork.
  39. Install the fork assemblies onto the first/second and fifth/reverse gear sleeves.
  40. Position the rear housing over the mainshaft, countershaft and reverse idler shaft assembly.

  41. Object Number: 143298  Size: SH

    Important: Two bolts of different length are used to secure the idler shaft segment to the rear housing. The forward (front) reverse idler shaft assembly hole houses the short bolt.

  42. Install the two bolts that secure the reverse idler shaft assembly to the rear housing.
  43. Finger tighten the two bolts.

    Important: 

       • Use new O-rings with the five output shaft bearing retainer to housing bolts.
       • Position the five new O-rings under the heads of the five output shaft to bearing retainer bolts prior to bolt installation.

  44. Position the five bolts and the O-rings that secure the rear housing to the output shaft bearing retainer.

  45. Object Number: 144203  Size: SH
  46. Connect the five output shaft bearing bolts in the following sequence:
  47. 29.1. Finger start bolts 1, 2, and 4.
    29.2. Finger start bolts 3 and 5.
    29.3. Finger tighten the bolts in the following order:

    1, 2, 3, 4, 5.

    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.

    29.4. Tighten the five output shaft bearing retainer to housing bolts in the following order:

    1, 2, 3, 4, 5.

    Tighten
    Tighten the bolts to 22 N·m (16 lb ft).

    29.5. Re-tighten the five output shaft bearing retainer to housing bolts in the following order:

    1, 2, 3, 4, 5.

    Tighten
    Tighten the bolts to 22 N·m (16 lb ft).

    29.6. Tighten the reverse idler shaft assembly to housing rear bolt.

    Tighten
    Tighten the reverse idler shaft assembly to housing rear bolt to 22 N·m (16 lb ft).

    29.7. Tighten the reverse idler shaft assembly to housing forward bolt.

    Tighten
    Tighten the reverse idler shaft assembly to housing forward bolt to 44 N·m (33 lb ft).

  48. Remove the rear housing assembly from the J 41663 .
  49. Place the rear housing assembly horizontally.


    Object Number: 143332  Size: SH
  50. Install the third/fourth fork onto the third and fourth gear synchronizer sleeve.
  51. Install the following components onto the rear housing:
  52. • The shift shaft bushing
    • The shift shaft lever
    • The shift shaft socket
  53. Install the shift shaft through the following components:
  54. • The third/fourth gear fork
    • The shift shaft bushing
    • The shift shaft lever
    • The first/second shift fork
    • The fifth/reverse shift fork
    • Place the shift shaft into the rear housing.
    • Push the shift shaft down when installing it into the rear housing.

    Object Number: 143327  Size: SH
  55. Install the 22 mm (0.866 in) shift shaft lever roll pin into the shift shaft lever.
  56. Make sure that the roll pin to set flush with the shift shaft lever assembly.

  57. Install the shift shaft socket and the 30 mm (1.18 in) roll pin onto the shift shaft.
  58. Make sure that the shift shaft socket roll pin is flush with the shift shaft socket hole.


    Object Number: 143314  Size: SH
  59. Install the shift shaft spring and plunger assembly into the shift shaft lever assembly.
  60. Important: The transmission must be in the 3rd or 4th gear position during the installation of the shift tower.

    After the shift tower has been installed to the transmission, the shifter can be engaged into other shift positions.

  61. Position the transmission into the third gear:
  62. 37.1. Center the shift shaft.
    37.2. Push the shift shaft all the way to the rear of the rear housing.
  63. Apply Loctite® 518 sealant to the mating surfaces of the rear housing.
  64. Use the J 36183 and the J 36184 in order to install the input shaft ball bearing into the front housing.
  65. Install the front counter shaft roller bearing into the front housing with petrolatum.
  66. Make sure that the small end of the counter shaft bearing is toward the front housing.


    Object Number: 143323  Size: SH
  67. Position the front housing onto the rear housing.

  68. Object Number: 144205  Size: SH
  69. Install the shift shaft detent blockout bushing pin into the top of the front housing.
  70. Install the shift shaft detent blockout bushing pin by hand in order to ensure that the detent lock pin installs into the shift shaft lever and the shift shaft bushing.


    Object Number: 143323  Size: SH
  71. Install the nine bolts which secure the front housing to the rear housing.
  72. Tighten

        • Tighten the nine housing bolts to 33 N·m (24 lb ft).
        • Tighten the shift shaft detent blockout bushing pin to 33 N·m (24 lb ft).

    Object Number: 144204  Size: SH
  73. Install the following components:
  74. • The shift shaft detent plunger (1)
    • The spring (2)
    • The detent plug (3)

    Object Number: 143320  Size: SH
  75. Install the snap ring on the input shaft front ball bearing.
  76. Apply RTV sealant to the mating surfaces of the input shaft bearing retainer.
  77. Install the input shaft bearing retainer to the front housing.

  78. Install the five bolts that secure the input shaft bearing retainer to the front housing.
  79. Tighten
    Tighten the bolts that secure the input bearing retainer to 29 N·m (21 lb ft).

  80. Install the backup light switch into the rear housing.
  81. Tighten
    Tighten the backup light switch to 37 N·m (28 lb ft).

  82. Add transmission oil. Refer to Lubrication Specifications .

  83. Object Number: 144191  Size: SH
  84. Use the J 36511 to install the oil fill plug.
  85. Tighten
    Tighten the oil fill plug to 23 N·m (17 lb ft).

Tools Required

    • J 22873 Slide Hammer
    • J 36183 Input Shaft Press Tube With Cap
    • J 36184 Input Shaft Press Tube Reducer
    • J 36511 Oil Fill Plug Hex Bit (17 mm)
    • J 41663 Assembly Pallet Main Shaft Adapter

    Object Number: 143340  Size: SH

    Important: Install the synchronizer sleeves with the offset teeth toward the second, third and fifth gear.

    Sleeves are identified with the following marks:

       • First and second: One groove on the outer diameter (OD) of the first gear
       • Third and fourth: Two grooves on the outer diameter (OD) of the third gear
       • Fifth and reverse: Two grooves on the outer diameter (OD) of the fifth gear
            One groove on the reverse gear

    Important: Lubricate all components during assembly.

    Use lubricant Synchromesh Transmission Fluid with friction modifier GM P/N 12377916 or equivalent.

  1. Position the following components onto the end of the output shaft:
  2. 1.1. The reverse gear
    1.2. The synchronizer blocking ring
    1.3. The fifth reverse synchronizer

    Use the J 22873 in order to install the fifth reverse synchronizer.

    1.4. The synchronizer blocking ring
    1.5. The snap ring
    1.6. The fifth gear

    Object Number: 143339  Size: SH
  3. Use the J 22873 in order to install the ball bearing.
  4. Install the snap ring to the mainshaft.
  5. Position the speed sensor gear down the main shaft two inches from the ball bearing.
  6. Use the J 22873 in order to position the ball bearing.

  7. Object Number: 144188  Size: SH
  8. Position the following components onto the input end of the main shaft:
  9. (Make sure that the scribed hub is correctly aligned.)

    6.1. The first gear
    6.2. The inner cone
    6.3. The middle cone
    6.4. The two synchronizer blocking rings
    6.5. The first and second gear synchronizer
    6.6. The first and second gear synchronizer hub

    Align the synchronizer rings with the keys on the first and second gear synchronizer. One synchronizer ring should be on each side of the synchronizer and the hub.

  10. Position the snap ring into the slot on the main shaft.

  11. Object Number: 144179  Size: SH
  12. Position the following components onto the input end of the main shaft:
  13. 8.1. The middle cone
    8.2. The inner cone
    8.3. The second gear
    8.4. The two piece split washer with the retainer ring.

    Object Number: 144172  Size: SH
  14. Install the third gear.
  15. Use the J 22873 in order to position the following components:
  16. 10.1. Two synchronizer blocking rings
    10.2. The third and fourth gear synchronizer
    10.3. The third and fourth gear synchronizer hub
  17. Align the synchronizer blocking rings with the keys on the third and fourth gear synchronizer.
  18. Position the snap ring.

  19. Object Number: 143341  Size: SH
  20. Position the following components onto the input end of the main shaft:
  21. 13.1. The pocket bearing
    13.2. The input shaft
  22. Turn over the main shaft.
  23. Reposition the main shaft onto the J 41663 .

  24. Press the counter shaft rear bearing onto the counter shaft.
  25. Press the snap ring on to the counter shaft.

  26. Object Number: 144206  Size: SH
  27. Position the counter shaft onto the J 41663 .
  28. Important: 

       • When assembling the reverse idler gear, make sure that the chamfer on the segment and the collar are facing up, toward the rear.
       • Make sure that the groove on the idler gear is toward the collar.

  29. Position the following components onto the reverse idler shaft:
  30. 18.1. The two O-rings
    18.2. The caged roller bearings
    18.3. The reverse idler gear
    18.4. The idler shaft support collar
  31. Position the reverse idler shaft assembly onto the J 41663 .

  32. Object Number: 144202  Size: SH
  33. Position the output shaft bearing retainer onto the mainshaft and the countershaft.
  34. Make sure that the output shaft bearing retainer is positioned behind the ball bearings on the mainshaft and the countershaft.
  35. Make sure that the fork end of the output shaft bearing retainer is positioned under the counter shaft ball bearing.
  36. Make sure that the hook end of the output shaft bearing retainer is positioned under the main shaft ball bearing.

  37. Object Number: 144206  Size: SH
  38. Install the fifth/reverse shift fork onto the first/second shift fork.
  39. Install the fork assemblies onto the first/second and fifth/reverse gear sleeves.
  40. Position the rear housing over the mainshaft, countershaft and reverse idler shaft assembly.

  41. Object Number: 143298  Size: SH

    Important: Two bolts of different length are used to secure the idler shaft segment to the rear housing. The forward (front) reverse idler shaft assembly hole houses the short bolt.

  42. Install the two bolts that secure the reverse idler shaft assembly to the rear housing.
  43. Finger tighten the two bolts.

    Important: 

       • Use new O-rings with the five output shaft bearing retainer to housing bolts.
       • Position the five new O-rings under the heads of the five output shaft to bearing retainer bolts prior to bolt installation.

  44. Position the five bolts and the O-rings that secure the rear housing to the output shaft bearing retainer.

  45. Object Number: 144203  Size: SH
  46. Connect the five output shaft bearing bolts in the following sequence:
  47. 29.1. Finger start bolts 1, 2, and 4.
    29.2. Finger start bolts 3 and 5.
    29.3. Finger tighten the bolts in the following order:

    1, 2, 3, 4, 5.

    29.4. Tighten the five output shaft bearing retainer to housing bolts in the following order:

    1, 2, 3, 4, 5.

    Tighten
    Tighten the bolts to 22 N·m (16 lb ft).

    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.

    29.5. Re-tighten the five output shaft bearing retainer to housing bolts in the following order:

    1, 2, 3, 4, 5.

    Tighten
    Tighten the bolts to 22 N·m (16 lb ft).

    29.6. Tighten the reverse idler shaft assembly to housing rear bolt.

    Tighten
    Tighten the reverse idler shaft assembly to housing rear bolt to 22 N·m (16 lb ft).

    29.7. Tighten the reverse idler shaft assembly to housing forward bolt.

    Tighten
    Tighten the reverse idler shaft assembly to housing forward bolt to 44 N·m (33 lb ft).

  48. Remove the rear housing assembly from the J 41663 .
  49. Place the rear housing assembly horizontally.


    Object Number: 143332  Size: SH
  50. Install the third/fourth fork onto the third and fourth gear synchronizer sleeve.
  51. Install the following components onto the rear housing:
  52. • The shift shaft bushing
    • The shift shaft lever
    • The shift shaft socket
  53. Install the shift shaft through the following components:
  54. • The third/fourth gear fork
    • The shift shaft bushing
    • The shift shaft lever
    • The first/second shift fork
    • The fifth/reverse shift fork
    • Place the shift shaft into the rear housing.
    • Push the shift shaft down when installing it into the rear housing.

    Object Number: 143327  Size: SH
  55. Install the 22 mm (0.866 in) shift shaft lever roll pin into the shift shaft lever.
  56. Make sure that the roll pin to set flush with the shift shaft lever assembly.

  57. Install the shift shaft socket and the 30 mm (1.18 in) roll pin onto the shift shaft.
  58. Make sure that the shift shaft socket roll pin is flush with the shift shaft socket hole.


    Object Number: 143314  Size: SH
  59. Install the shift shaft spring and plunger assembly into the shift shaft lever assembly.
  60. Important: The transmission must be in the 3rd or 4th gear position during the installation of the shift tower.

    After the shift tower has been installed to the transmission, the shifter can be engaged into other shift positions.

  61. Position the transmission into the third gear:
  62. 37.1. Center the shift shaft.
    37.2. Push the shift shaft all the way to the rear of the rear housing.
  63. Apply Loctite® 518 sealant to the mating surfaces of the rear housing.
  64. Use the J 36183 and the J 36184 in order to install the input shaft ball bearing into the front housing.
  65. Install the front counter shaft roller bearing into the front housing with petrolatum.
  66. Make sure that the small end of the counter shaft bearing is toward the front housing.


    Object Number: 143323  Size: SH
  67. Position the front housing onto the rear housing.

  68. Object Number: 144205  Size: SH
  69. Install the shift shaft detent blockout bushing pin into the top of the front housing.
  70. Install the shift shaft detent blockout bushing pin by hand in order to ensure that the detent lock pin installs into the shift shaft lever and the shift shaft bushing.


    Object Number: 143323  Size: SH
  71. Install the nine bolts which secure the front housing to the rear housing.
  72. Tighten

        • Tighten the nine housing bolts to 33 N·m (24 lb ft).
        • Tighten the shift shaft detent blockout bushing pin to 33 N·m (24 lb ft).

    Object Number: 144204  Size: SH
  73. Install the following components:
  74. • The shift shaft detent plunger (1)
    • The spring (2)
    • The detent plug (3)

    Object Number: 143320  Size: SH
  75. Install the snap ring on the input shaft front ball bearing.
  76. Apply RTV sealant to the mating surfaces of the input shaft bearing retainer.
  77. Install the input shaft bearing retainer to the front housing.

  78. Install the five bolts that secure the input shaft bearing retainer to the front housing.
  79. Tighten
    Tighten the bolts that secure the input bearing retainer to 29 N·m (21 lb ft).

  80. Install the backup light switch into the rear housing.
  81. Tighten
    Tighten the backup light switch to 37 N·m (28 lb ft).

  82. Add transmission oil. Refer to Lubrication Specifications .

  83. Object Number: 144191  Size: SH
  84. Use the J 36511 to install the oil fill plug.
  85. Tighten
    Tighten the oil fill plug to 23 N·m (17 lb ft).