Operation CHARM: Car repair manuals for everyone.

Shimming Procedures



Shimming Procedures

Input Shaft, Mainshaft, and Countershaft

Tools Required
* J 8001 Dial Indicator Set
* J 39444-1 Countershaft End Play Rod

1. Rotate the transmission adapter plate to the vertical position.




2. Install the following assemblies in order:

1. The input shaft to the adapter plate
2. Align the 4th speed gear blocking ring to the input shaft.
3. The mainshaft assembly
4. The countershaft (lift up the mainshaft enough to install the countershaft.)




3. Install the transmission case.





Notice: Refer to Fastener Notice.

4. Install the adapter plate to transmission case bolts.

Tighten the bolts to 36 N.m (27 Ib ft).




5. Measure the input shaft/mainshaft end play using the following procedure:

1. Place the tip of the J 8001 -3 on the end of the mainshaft.
2. Move the input shaft up and down.
3. Record the measurement.

6. Select a shim to achieve 0.00-0.05 mm (0.000-0.002 in) preload.
7. Remove the J 8001 -3.




8. Measure the countershaft end play using the following procedure:

1. Place the tip of the J 8001 -3 on the end of the countershaft.
2. Move the countershaft up and down.
3. Record the measurement.

9. Select a shim to achieve 0.00-0.05 mm (0.000-0.002 in) preload.
10. Remove the J 8001 -3.




11. Remove the adapter plate plug (MM6 only).
12. Remove the auxiliary coolant pump bolt (2) (MY6 only).
13. Remove the auxiliary coolant pump (1) (MY6 only).




14. Remove the shift lever guide bolts.




15. Remove the adapter plate to the transmission case bolts.




16. Remove the transmission case.




17. Remove the following parts in order:

1. The countershaft (lift up the mainshaft enough to remove the countershaft).
2. The mainshaft assembly
3. The input shaft from the adapter plate
4. The input shaft bearing race
5. The countershaft bearing race




18. Remove the input shaft bearing race.
19. Remove the input shaft bearing shim and discard.
20. Install the new input shaft bearing shim, and the original bearing race.




21. Remove the countershaft bearing race.
22. Remove the countershaft bearing shim and discard.
23. Install the new input shaft bearing shim, and the original bearing race.
24. Refer to Transmission Assemble (Z06).

Countershaft Extension

Tools Required
* J 8001 Dial Indicator Set
* J 39444-2 Countershaft Extension End Play Rod





Important: The following procedure cannot be performed accurately until the countershaft shimming procedure has been completed and the transmission has been assembled to the point of installing the countershaft extension.

1. Rotate the transmission in the horizontal position.
2. Install the countershaft extension to the countershaft. Make sure the splines fully engage.





Notice: Refer to Fastener Notice.

3. Install the extension housing and the extension housing retainer bolts.

Tighten the bolts to 35 N.m (26 Ib ft).




4. Remove the adapter plate plug (MM6 only).
5. Remove the auxiliary coolant pump bolt (2) (MY6 only).
6. Remove the auxiliary coolant pump (1) (MY6 only).




7. Install the J 39444-2 through the adapter plate plug hole.
8. Screw J 39444-2 into the countershaft extension.




9. Measure the countershaft extension end play using the following procedure:

1. Install a J 8001 so the tip is on the end of the countershaft extension end play rod.
2. Rotate the transmission in the vertical position.
3. Move the countershaft extension up and down using the J 39444-2.
4. Record the measurement.

10. Select a shim to achieve 0.05-0.13 mm (0.002-0.005 in) axial play.
11. Remove the J 8001.
12. Remove the J 39444-2.




13. Apply sealant GM P/N 12346004, (Canadian P/N 10953480) or the equivalent to the plug threads.




14. Install the adapter plate plug (MM6 only).

Tighten the plug to 27 N.m (20 Ib ft).

15. Install the auxiliary coolant pump (1) (MY6 only).
16. Install the auxiliary coolant pump bolt (2) (MY6 only).

Tighten the bolt to 19 N.m (14 lb ft).




17. Install the countershaft extension.
18. Install the countershaft extension bearing race.




19. Install the extension housing bolts and the extension housing.