Y Car MM6 and MY6
Transmission Assemble (Y Car MM6 and MY6)
Shift Shaft Assemblies and Gear Clusters Installation
^ Tools Required
- J 36850 Transjel Lubricant Assembly Lube
1. Lubricate all components as assembly progresses, using J 36850.
2. Install the input shaft in the adapter plate.
3. Assemble the shift shaft to the mainshaft.
4. Install the neutral return roll pin to the shift shaft.
5. Install the mainshaft and the shift shaft assembly into the adapter plate.
6. Install the countershaft assembly using the following sequence:
1. Lift up the mainshaft assembly enough in order to install the countershaft assembly.
2. Install the countershaft assembly.
3. Lift the mainshaft assembly enough in order to rotate the input shaft to engage the synchronizer keys with 4th gear blocking ring.
7. Install the 5th/6th and the reverse shift shaft.Align the slots of the shift shaft levers with the interlock plate.
Reverse Lockout Assembly Assemble
1. Caution: The reverse lockout assembly is under spring pressure. Exercise caution when removing the retainer ring, as bodily injury may result.
Install the reverse lockout plunger (6).
2. Install the reverse lockout outer spring (5).
3. Install the reverse lockout collar (4).
4. Compress the reverse lockout plunger and the collar (4) in a vise and Install the retainer ring (3).
5. Install the reverse lockout inner spring (2).
6. Install the reverse lockout components in the body (1).
7. Install the retainer ring (7).
8. Install the O-ring to body (8).
Transmission Case Installation
^ Tools Required
- J 41099 Skip Shift Sensor Remover/Installer
- J 36850 Transjel Lubricant
Important: Lubricate all components as the assembly progresses. Use J 36850 or the equivalent.
1. Apply sealant GM P/N United States 12345739, GM P/N Canada 10953472 or equivalent to the transmission case to adapter plate mating surface.
2. Install the ball detent and the spring in the front offset lever.
3. Do the following in order to install the transmission case and the offset lever:
1. Shift the transmission into NEUTRAL in order to keep the 3rd/4th shift shaft from engaging.
2. Install the offset lever.
3. Compress the front offset lever together while sliding it onto the shift shaft. This will prevent the spring release of the inner components.
4. Slide the transmission case onto the gear clusters and the shift rail components.
4. Apply threadlock GM P/N United States 12346004, GM P/N Canada 10953480 or equivalent to the threads of the shift lever guide bolts.
5. Notice: Refer to Fastener Notice in Service Precautions.
Install the shift lever guide bolts and pull up on 5th/6th and reverse shift rail assembly. This will help align the slot of the shift interlock plate with the guide bolt hole.
^ Tighten the bolts to 27 Nm (20 ft. lbs.).
6. Install the adapter plate to transmission case bolts.
^ Tighten the bolts to 48 Nm (36 ft. lbs.).
7. Install the magnets into the transmission case.
8. Install the offset lever roll pin.
9. Install the shift detent assembly.
^ Tighten the detent assembly to 40 Nm (30 ft. lbs.).
10. Apply sealant GM P/N United States 12345739, GM P/N Canada 10953472 or the equivalent to the mating surface of the cover plate.
11. Install the transmission case cover and the case cover bolts.
^ Tighten the bolts to 20 Nm (15 ft. lbs.).
12. Install the reverse lockout body and bolt in the cover plate.
^ Tighten the bolts to 18 Nm (13 ft. lbs.).
13. Install the reverse lockout solenoid to reverse lockout body assembly, using the J 41099.
^ Tighten the solenoid to 40 Nm (30 ft. lbs.).
14. Install the computer aided gear select solenoid.
^ Tighten the solenoid to 40 Nm (30 ft. lbs.).
Countershaft Extension Installation
1. Position the transmission in the horizontal position.
2. Install the countershaft extension assembly and the 5th/6th shift fork. The splines of the countershaft extension must engage the splines of the countershaft.
3. Install the 5th/6th shift fork retainer ring.
5th/6th Speed Driven Gear Installation
^ Tools Required
- J 39441 5th/6th Driven Gear Installer
- J 39441-10 5th Gear Installer Adapter
Install the 5th/6th speed driven gear using the J 39441 and J 39441-10. The smaller outside diameter (OD) of the gear faces down.
Reverse Shift Fork Installation
1. Install the reverse shift fork, the synchronizer and the thrust washer.
2. Install a new shift fork retainer ring.
3. Install the reverse synchronizer retainer ring.
Reverse Speed Gear Installation
1. Install the following parts in order:
1. The blocking ring
2. The wave washer
3. The wave washer so the concave side faces the blocking ring
4. The caged needle bearing
5. The reverse speed gear
6. The thrust washer
7. The retainer ring
2. Install the following parts in order:
1. The spacer
2. The roller bearing
3. The spacer
4. The roller bearing retainer ring
Extension Housing Assemble
^ Tools Required
- J 44395 Transmission Holding Fixture
1. Install the following parts in order:
1. The funnel
2. The selective shims.
3. The countershaft extension bearing race
2. Install the following parts in order:
1. The reverse idler shaft
2. The roller bearing
3. The reverse idler gear
3. Apply GM P/N 12345382 (Canadian P/N 10953489) or the equivalent to the reverse idler shaft brackets bolt threads.
4. Notice: Refer to Fastener Notice in Service Precautions.
Install the following parts in order:
1. The reverse idler shaft bracket
2. The reverse idler shaft bracket bolts
^ Tighten the bolts to 25 Nm (18 ft. lbs.).
5. Apply sealant GM P/N 12345739 (Canadian P/N 10953472) or equivalent to the extension housing to the transmission case mating surface.
6. Apply thread sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the top 2 extension housing bolts.
Important: Align the 5th/6th shift shaft to the extension housing bore in order to install the extension housing.
7. Install the extension housing.
8. Install the extension housing bolts.
^ Tighten the bolts to 48 Nm (36 ft. lbs.).
9. Install the vent tube.
10. Remove the J 44395.
11. Install the remaining 2 adapter plate bolts (1) and (2).
^ Tighten the adapter plate bolts to 48 Nm (36 ft. lbs.).