Transmission Assemble (Rear Wheel Drive)
TRANSMISSION ASSEMBLY- Tools Required
- J 3289-20 Base Holding Fixture
- J 6133-01 Speedometer Rotor Installer
- J 8763-02 Holding Fixture C-Clamp
- J 8763-21 Balance Bracket for C-Clamp
- J 25070 Heat Gun
- J 36515 Assembly Pallet
- J 36515-10 Retainer Alignment Cable (2WD Models Only)
- J 36515-15 Mainshaft Adapter
- J 36515-16 Countershaft Adapter
- J 36824 Transmission Adapters
- J 36511 Oil Fill Plug Hex Bit (17 mm)
IMPORTANT: Some parts require an assembly lubricant. Use TRANSJEL(R) or equivalent.
1. Install the pilot bearing into the input shaft.
- Turn the small diameter of the bearing cage toward the input shaft.
- Retain the bearing with TRANSJEL(R) or equivalent.
2. Install the following parts on the assembly fixture J 36515-15 and J 36515
2.1. The input shaft (1)
2.2. The pilot bearing (2)
2.3. The synchronizer ring (3)
2.4. The mainshaft assembly (4)
3. Install the following parts on the mainshaft and on the assembly fixture J 36515-16:
3.1. The countershaft assembly (1)
3.2. The reverse idler assembly (2)
3.3. The 1st/2nd speed gear shift fork (3)
3.4. The 5th/reverse speed gear shift fork (4)
4. Install the following components:
4.1. The output shaft bearing assembly (2)
4.2. A new mainshaft snap ring (1)
5. Heat the reluctor wheel for 7-10 minutes at 120°C (250°F).
IMPORTANT: Before assembly, heat the bore of the rear main housing output shaft bearing.
6. Install a new vehicle speed sensor reluctor wheel. Use J 6133-01, if necessary.
7. Heat the rear main housing bore 3-5 minutes.
Use J 25070.
IMPORTANT: Press each bearing roller towards the race. This will secure them for easier assembly.
8. Install the countershaft bearing.
- Use TRANSJEL(R) or equivalent in order to retain the bearing.
- The smaller diameter of the bearing cage goes into the bearing race of the housing.
9. Install the following components:
9.1. J 36515-10 through the bolt-holes in the rear housing.
9.2. Screw the threaded cable ends into the output shaft bearing retainer (1).
9.3. Position the notch in the bearing retainer towards the oil delivery tube assembly (2).
IMPORTANT: Bring the housing straight down. If you feel resistance at about 7 mm (1/4 inch), then the counter shaft bearing rollers are cocked. Repeat the procedure. Do not force the housing down.
10. Install the rear housing assembly.
10.1. Make sure to line up the reverse idler shaft with the hole in the housing.
10.2. Rotate the housing back and forth while pulling down.
10.3. Pull up on J 36515-10 while installing the rear housing.
11. Apply pipe sealant with Teflon(TM) GM P/N 1052080 or equivalent to the bolt holes of the rear housing.
12. Apply GM P/N 12345382 threadlocker to the bolt threads.
13. Install the rear bearing retainer bolts. Do not tighten the bolts.
14. Remove J 36515-10.
- Tighten the rear bearing retainer bolts to 22 Nm (116 ft. lbs.).
15. Lay the rear housing assembly down on the workbench. Remove J 36515, J 36515-15, and J 36515-16 from the housing.
16. Apply pipe sealant with Teflon(TM) GM P/N 1052080 or equivalent to the bolt-hole.
17. Apply GM P/N 12345382 threadlocker or equivalent to the bolt threads.
18. Install the following components:
18.1. The idler shaft support
18.2. The idler shaft bolts
18.3. Line up the bolt threads in the idler shaft support with the bolt hole.
18.4. Hold the reverse idler shaft against the idler support while tightening the bolts.
^ Tighten the bolt to 22 Nm (16 ft. lbs.).
19. Install J 8763-21, J 8763-02, and J 36824 on the transmission housing.
20. Install the 3rd/4th sped gear shift fork onto the 3rd/4th speed gear synchronizer sleeve.
Align all three insert notches.
21. Assemble the following parts onto the shift shaft:
21.1. The 3rd/4th speed gear shift fork. Make the detent reliefs in the shift shaft point out (1).
21.2. The shift lever (2).
21.3. The block-out bushing (3).
21.4. The 1st/2nd speed gear shift fork (4).
21.5. The shift socket (5).
22. Slide the shift shaft all the way into the housing.
23. Install a new roll pin into the shift lever.
23.1. Rotate the shift shaft and the shift lever/block-out bushing assembly. Make sure the roll pin holes are aligned and horizontal.
23.2. Support the shift shaft while installing the roll pin.
23.3. Install the roll pin flush with the shift lever.
24. Install the detent spring and the ball plunger into the hole in the shift lever.
24.1. Rotate the shift shaft counterclockwise. The shift lever should be almost into the 5th/Reverse speed gear insert notch.
24.2. Install the spring (1) and the ball plunger (2) into the shift lever.
24.3. Rotate the shift shaft until the shift lever aligns with the 3rd/4th speed gear insert.
NOTICE: Excessive force peens the shift shaft and damages the shift shaft bearing. This causes increased shift effort.
IMPORTANT: Use the rear roll pin hole on the M50 transmission.
25. Install the shift socket roll pin.
25.1. Align the holes in the shift socket and the shift shaft.
25.2. Drive the roll pin flush with the bottom of the shift socket.
26. Apply gasket maker GM P/N 1052943 or equivalent to both sides of the isolator plate.
27. Install the isolator plate onto the housing.
The thin side of the plate should be on the left side of the transmission housing.
28. Install the shift lever.
29. Install 4 bolts.
- Tighten the bolts to 8.5 Nm (75 inch lbs.).
IMPORTANT: The smaller diameter of the bearing cage goes into the bearing race.
30. Install the countershaft bearing in the front housing.
30.1. Apply TRANSJEL(R) or equivalent on the bearing rollers.
30.2. Press each bearing roller into the cage.
30.3. Apply TRANSJEL(R) or equivalent to the bearing race on the input shaft.
IMPORTANT: Bring the housing straight down. If you feel resistance at about 7 mm (1/4 inch), then the rollers are cocked. Repeat the procedure. Do not force down the housing.
31. Install the front housing.
32. Install the 2 housing dowel pins.
Drive the dowel pins into the front housing flange.
33. Install the housing bolts.
- Do not tighten the bolts.
- Tip the transmission vertically.
34. Install a new snap ring on the input shaft. It may be necessary to pull out on the input shaft in order to install the snap ring.
IMPORTANT: Do not allow the gasket maker material to plug the oil return hole. This reduces oil flow through the input shaft bearing. Premature bearing failure could result.
35. Apply gasket maker GM P/N 1052943 or equivalent to the inside edge of the bearing retainer bolt hole pattern.
36. Install the following components:
36.1. The input shaft bearing retainer assembly (Align the oil drain back hole with the hole in the housing.)
36.2. The six bolts
^ Tighten the bolts to 8.5 Nm (75 inch lbs.).
37. Apply pipe sealant to the detent plunger plug. Use pipe sealant with Teflon(TM) GM P/N 1052080 or equivalent.
38. Install the following components:
38.1. The shift shaft detent plunger
38.2. The shift shaft detent spring
38.3. The plug (Use a brass drift in order to install the plug.)
39. Coat the vehicle speed sensor O-ring with clean transmission lubricant. Use Synchromesh Transmission Fluid GM P/N 12345349 or equivalent.
40. Install the electronic speed sensor:
40.1. Use a new O-ring.
40.2. Install the bolt.
^ Tighten the bolt to 9 Nm (80 inch lbs.).
41. Apply pipe sealant to the threads of the backup lamp switch assembly. Use pipe sealant with Teflon(TM) GM P/N 1052080 or equivalent.
42. Install the backup lamp switch assembly.
- Tighten the switch to 9 Nm (80 inch lbs.).
43. Remove J 8763-02 and J 36824.
44. Install 2 bottom housing bolts.
- Tighten the bolts to 35 Nm (26 ft. lbs.).
45. Install the shift shaft block-out bushing pin.
- Tighten the bolt to 25 Nm (18 ft. lbs.).
46. Fill the transmission with lubricant.
46.1. Refer to Fluid Capacities in General Information.
46.2. Use Synchromesh Transmission Fluid GM P/N 12345349 or equivalent.
46.3. Remove the oil fill plug. Use J 36511.
46.4. Install the transmission lubricant.
46.5. Install the oil fill plug.
^ Tighten the oil fill plug to 60 Nm (44 ft. lbs.).