Unit Assembly

- Tools Required:
- J 22828 Countershaft Bearing and Input Shaft Bearing Installer
- J 23642-01 Transmission Holding Fixture
- J 24462 Transmission Adapter Plate
- J 38856 Countershaft Bearing Cone and Retainer Installer

INSTALL OR CONNECT
1. Fifth gear shift lever.
2. Fifth gear shift lever shaft.
3. Fifth gear shift lever retaining pin.





- Hold fifth shift lever back out of the way using a rubber band.
- Ensure the notches that retain the fifth gear fork are to the outside of the case.
4. Countershaft front bearing cup using J 38856.
5. Countershaft assembly into the transmission case.





6. Countershaft rear bearing using J 22828.
- Raise and support the Countershaft assembly by positioning a wood block between the front of the Countershaft and the transmission case.
7. Reverse idler gear, bearings, spacer, and washers into the transmission case.
8. Reverse idler gear shaft.
9. Countershaft rear bearing cup.
10. Countershaft shim(s) and bearing retainer plate.
11. Countershaft bearing retainer plate bolts.

Tighten
- Countershaft bearing retainer bolts to 35 N.m (26 lb. ft.).





Measure
- Countershaft end play.
A. Set the dial indicator up on the end of the countershaft.
B. Use screwdriver or the equivalent to lift Countershaft up and down to measure end play.
C. Countershaft end play should be 0.05-0.15 mm (0.002-0.006 inch). Adjust by adding or removing shim(s) under bearing retainer plate.
D. Remove bolts and apply Loctite Dri-Loc 201 or equivalent to the bolts and tighten.





12. Countershaft bearing cap using J 38856.
- Ensure outer lip is hit evenly until flush with case.





13. Mainshaft assembly into the transmission case.
14. Mainshaft rear bearing cup, shim(s), and retainer plate.
15. Mainshaft bearing retainer plate bolts.
- Finger tighten only.
16. Countershaft thrust washer retainer pin and countershaft thrust washer.
17. Fifth gear bearings and spacer onto the countershaft.
18. Fifth gear assembly onto the fifth shift rail and the countershaft.
- Slide fifth gear fork and fifth gear assembly onto the shift rail.
19. Fifth gear clutch gear snap ring.
20. Fifth gear shift fork roll pins.
- Support the overdrive fork and drive the roll pins downward from the top of the fork.





21. Main drive gear bearing and drive gear into the transmission case.





22. Main drive gear bearing retainer.
- Position retainer with oil hole at the top-center position.
- Apply GM P/N 1052942 or the equivalent sealant.
- Use care not to seal off oil hole
23. Main drive gear retainer bolts.

Tighten
- Main drive gear retainer bolts to 31 N.m (23 lb. ft.).
- Mainshaft bearing retainer plate bolts to 35 N.m (26 lb. ft.).





Measure
Mainshaft end play.
A. Set the dial indicator up on-the end of the mainshaft.
B. Use screwdriver or equivalent to lift mainshaft up and down to measure end play.
C. Mainshaft end play should be 0.05-0.15 mm (0.002-0.006 inch). Adjust by adding or removing shim(s) under mainshaft bearing retainer plate.
D. Remove bolts and apply Loctite Dri-Loc 201 or equivalent to the bolts and tighten.





24. Rear oil retainer to the transmission case.
25. Rear oil retainer to the transmission case bolts.

Tighten
- Rear oil retainer bolts to 54 N.m (40 lb. ft.).

26. Yoke assembly.
27. Spline seal, washer, and a new nut.

Tighten
- Yoke nut to 441 N.m (325 lb. ft.).

28. Fill the transmission with the proper amount of lubricant.

Important
- Use of any lubricant other than Castro Syntorq LT transmission fluid or equivalent will result in transmission failure.

29. Shift cover to the transmission case.
- Apply GM P/N 1052942 or the equivalent to the mating surfaces.
30. Shift cover to the transmission case bolts.

Tighten
- Shift cover bolts to 23 N.m (17 lb. ft.).





31. Shift tower isolator plate to the shift cover.
32. Shift tower to the isolator plate.
33. Shift tower to shift cover bolts.

Tighten
- Shift tower bolts to 60 N.m (53 lb. in).