Manual Transmission Comes Out of Gear (Install New Shift Shaft Lever)

Some owners may comment on the transmission coming out of gear. Typically 1st gear is most affected.

This condition may be due to a design change of the shift shaft lever that eliminated the detent plunger hole, spring and plunger.

Install the new shift lever that has been updated with the detent plunger hole.

Tools Required

1. Remove the transmission. Refer to Transmission Replacement in Transmission/Transaxle - Manual Transmission.



2. Remove the oil fill plug.

Important: The transmission must remain in 3rd or 5th gear in order to prevent losing the shift shaft lever spring and plunger.

3. If the transmission is not in 3rd or 5th gear, reinstall the shift control housing and shift the transmission in 3rd or 5th gear.
4. Place a suitable container under the transmission assembly in order to drain the remaining transmission fluid.



5. Remove the oil drain plug.
6. Remove the gasket material from the housing.



7. Remove the back-up lamp switch.



8. If RWD, remove the bolt for the vehicle speed sensor.
9. Remove the vehicle speed sensor and O-ring.



10. Remove the shift shaft detent pin.



11. Using special tools J 36509 (1) and J 23907 (2) , remove the detent plug, spring, and detent plunger.



12. Remove the 6 bolts securing the input shaft bearing retainer to the clutch housing.
13. Remove the retainer by screwing two of the removed bolts into the threaded holes in the retainer.



14. Remove the input shaft bearing retainer ring.



15. Remove the bolts securing the clutch housing to the rear case.




Notice: The case sealing surface is a machined surface. Prevent the case sealing surface from getting nicks, scratches or other damage. Damage to the case sealing surface may cause leakage.

16. Separate the clutch housing from the rear case using a soft-face hammer. Do not pry at the sealing surfaces.



17. Remove the countershaft front bearing.



18. Remove the shift shaft lever roll pin.

18.1.

Rotate the shift shaft lever finger down.

18.2.

Support the shift shaft end.

18.3.

Drive out the roll pin.

18.4.

Ensure that the roll pin clears the 2nd speed gear.




19. Remove the shift shaft socket roll pin.

19.1.

Align the shift shaft socket in the center of the case opening.

19.2.

Using a 5 mm (3/16 in) punch, remove the roll pin.




20. Remove the following components:

20.1.

The shift shaft

20.2.

The shift shaft socket

20.3.

The shift shaft lever

20.4.

The shift shaft block out bushing




21. Rotate the 3rd/4th speed gear shift fork counterclockwise.
22. Remove the 3rd/4th speed gear shift fork from the transmission case.

1. Install the 3rd/4th speed gear shift fork onto the 3rd/4th speed gear synchronizer sleeve.



2. Slide the shift shaft through the following parts:

2.1.	The 3rd/4th speed gear shift fork. Ensure that the detent reliefs, in the shift shaft, point to the front of the transmission.

2.2.	The NEW shift lever

2.3.	The block-out bushing

2.4.	The 1st/2nd speed gear shift fork

2.5.	The 5th/Reverse shift fork

2.6.	The rear case bushing and bearing

2.7.	The shift socket




3. Install a NEW roll pin into the shift lever. The end of the spiral must face toward the direction of the thrust.

3.1.	Rotate the shift shaft and the shift lever/block-out bushing assembly. Ensure the roll pin holes are aligned and horizontal.

3.2.	Support the shift shaft while installing the roll pin.

3.3.	Install the roll pin flush with the shift lever.





Important: On the S/T trucks, the shift shaft has only one hole. The C/K trucks have 2 holes on the shift shaft; use the front roll pin hole (1).

4. Install the shift shaft and shift shaft socket and roll pin.

4.1.	Align the holes in the shift shaft socket and the shift shaft.

4.2.	Drive the roll pin flush with the bottom of the shift shaft socket.




5. Install the detent spring and the ball plunger into the hole in the shift lever.

5.1.	Rotate the shift shaft counterclockwise. The shift lever should be almost into the 5th/Reverse speed gear insert notch.

5.2.	Install the spring and the ball plunger (1) into the shift lever (2).

5.3.	Rotate the shift shaft until the shift lever aligns with the 3rd/4th speed gear insert.

Important: The transmission must remain in 3rd or 5th gear in order to prevent losing the shift shaft lever spring and plunger.

6. Shift the transmission into 3rd or 5th gear.




Important: The smaller diameter of the bearing cage goes into the bearing race.

7. Install the countershaft bearing onto the countershaft. Ensure the smaller diameter side of the bearing is positioned toward the front case half.
8. Fill the front countershaft bearing race with J 36850, transmission assembly lubricant, or equivalent.



9. Apply gasket maker, P/N 1052943 (in Canada use 109534791), or equivalent to the front housing sealing surface.
10. Align the dowel pins in the clutch housing to the rear case.
11. Install the clutch housing to the rear case.




Important: Do not tighten the housing bolts.

12. Install the housing bolts.



13. Install a new retaining ring on the input shaft. It may be necessary to pull out on the input shaft in order to install the retaining ring.




Important: Do not allow sealant into the oil return hole in the housing or bearing retainer.

14. Apply RTV sealer, P/N 12345739 (in Canada use P/N 10953541), or equivalent to the inside edge of the bearing retainer mating surface.



15. Install the input shaft bearing retainer to the housing with 6 bolts. Align the retainer oil drain hole with the drain hole in the housing.

Tighten
Tighten the retainer bolts to 14 N·m (10 lb ft).

16. Rotate the input shaft a few turns to align the transmission bearings and to test for any excessive binding.
17. Tighten the front to rear housing bolts.

Tighten
Tighten the housing bolts to 35 N·m (26 lb ft).




18. Install the following components:

18.1.

The shift shaft detent plunger

18.2.

The shift shaft detent spring

Important: Apply pipe sealant, P/N 12346004 (in Canada use P/N 10953480), or equivalent to the detent plug.

18.3.

The shift shaft detent plug




19. If RWD vehicle, coat the speed sensor O-ring with Synchromesh Transmission Fluid, P/N 12345349 (in Canada use P/N 10953465), or equivalent.
20. Install the speed sensor, O-ring, and bolt.

Tighten
Tighten the bolt to 16 N·m (12 lb ft).




21. Install the backup lamp switch. Apply pipe sealant, P/N 12346004 (in Canada use P/N 10953480), or equivalent to the threads of the backup lamp switch.

Tighten
Tighten the switch to 37 N·m (27 lb ft).




22. Install the shift shaft detent pin.

Tighten
Tighten the detent pin to 25 N·m (18 lb ft).

Important: To prevent the transmission fluid from spilling while installing the transmission in the vehicle, fill the transmission after installing with Synchromesh Transmission Fluid, P/N 12345349 (in Canada use P/N 10953465).

23. Install the transmission. Refer to Transmission Replacement in Transmission/Transaxle - Manual Transmission.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: