22. Transmission Assemble
Transmission Assemble^ Tools Required
- J 8092 Driving Handle
- J 8614-01 Flange Holding Fixture
- J 21465-13 Driver Handle Extension
- J 25070 Heat Gun
- J 26900-12 Dial Indicator (Metric)
- J 29763 Dial Indicator
- J 36850 Transjel Lubricant
- J 44725 Gear Pack Assembly Fixture
- J 44731 Input Shaft Oil Seal Installer
- J 44732 Rear Oil Seal Installer
- J 44733 Input Shaft Bearing Race Remover
- J 44735 Installation Tube
- J 44736 Bridge and Forcing Screw
- J 44738 Counter Shaft Bearing Race Remover
- J 44739 Dial Indicator Bracket
- J 44745 Countershaft Bearing Race Installer
- J 44746 Mainshaft and Input Shaft Bearing Race Installer
Notice: Various transmission components require heating to 150°C (300°F) for 30 minutes for proper installation. Overheating may damage the components. Under-heating the components may cause hard installation, which may damage the components.
Important: Certain transmission components require preheating to 150°C (300°F). In order to preheat the components use an electric oven. It is recommended to purchase a roaster/oven style locally. The oven should have a temperature setting thermostat. Lubricate all of the bearings, shafts, and synchronizers with transmission fluid GM P/N 12378515 during installation.
1. Preheat the following for 30 minutes to 150°C (300°F) in an electric oven:
^ The 6th gear bearing bushing
^ The reverse gear bearing bushing
^ The reverse gear thrust washer
^ The main shaft rear bearing
2. Turn over the mainshaft assembly 180 degrees so that the input shaft is on the J 44725. Hold the input shaft to the mainshaft while turning over.
3. Position the countershaft on the J 44725. Roll the countershaft into place to merger the countershaft and main shaft gears.
4. Install the spacer for the 6th speed gear synchronizer hub on the countershaft.
5. Assemble the 2nd/3rd shift fork and shift shaft and the 4th/5th shift fork and shift shaft in the interlock plate.
^ The part number end of the shift shafts go up.
^ The part number side of the interlock plate goes down.
6. Install the 2nd/3rd shift fork and the 4th/5th shift fork in the synchronizer sleeves.
7. Install the intermediate case over the countershaft, the main shaft, 2nd/3rd shift shaft, and the 4th/5th shift shaft.
^ Align the shift shafts straight with the shift shaft bearings.
^ Wiggle the intermediate case over the shift shafts while installing.
8. Install the shift interlock plate to the intermediate case. The part number side faces away from the intermediate case.
Notice: Refer to Fastener Notice in Service Precautions.
9. Install the interlock plate bolts. Ensure the shoulder of the bolts do not catch on the plate.
^ Tighten the interlock plate bolts to 10 Nm (88 inch lbs.).
10. Ensure the interlock plate moves freely.
11. Install the retaining ring in the 6th speed gear synchronizer hub, if removed.
12. Install the 6th speed gear synchronizer hub on the countershaft.
^ The hub side with the retaining ring goes toward the intermediate case.
^ The hub should slide on the countershaft.
13. If not already assembled, assemble the 6th gear synchronizer assembly. The 6th gear synchronizer springs are 22.7 mm (0.893 inch) long.
13.1. Install all three springs and the pressure pieces in the synchronizer sleeve.
13.2. Install the 6th gear synchronizer sleeve on the hub. The part numbered side goes up.
Important: In order to prevent the springs and pressure pieces from jumping out of position, install the 6th gear synchronizer blocking ring. Then move the sleeve to lock the pressure pieces in position.
13.3. Install the 6th gear synchronizer blocking ring. Align the tabs on the blocking ring with the slots in the hub.
13.4. Pull up on the sleeve to lock the pressure pieces in the neutral position.
Caution: Refer to Proper Handling of Preheated Components Caution in Service Precautions.
14. Wearing protective gloves install the preheated 6th gear bushing on the countershaft. Rotate the bushing while installing in order to seat fully and squarely.
15. Install the 6th speed gear bearing (3).
16. Install the 6th speed gear (2).
17. Install the 6th speed gear spacer washer (1).
18. Lightly lubricate the components with GM P/N 12378515.
19. Install the retaining ring for the 6th speed gear.
^ The retaining rings are different thicknesses.
^ Select a retaining ring that fills the groove.
^ Retaining ring tabs should be under the gear teeth.
^ Ensure the retaining ring is fully seated.
20. If the 1st/reverse synchronizer requires assembly use the following procedure:
20.1. Lightly lubricate the components with GM P/N 12378515.
20.2. With the oil grooves or the part number side up, install the synchronizer hub on the 1st gear synchronizer blocking ring.
20.3. With the synchronizer sleeve chamfer side down install the sleeve on the hub.
20.4. Install the synchronizer springs and pressure pieces.
20.5. Install the reverse gear synchronizer blocking ring.
21. Install the following on the mainshaft:
21.1. Lightly lubricate the bearings with GM P/N 12378515.
21.2. 1st gear bearings
21.3. 1st speed gear
21.4. 1st/reverse gear synchronizer assembly with the hub part numbers facing up
Caution: Refer to Proper Handling of Preheated Components Caution in Service Precautions.
22. Wearing protective gloves install the preheated reverse speed gear bushing on the main shaft. Rotate the bushing while installing to ensure the bushing is fully and squarely seated.
23. Install the reverse gear bearings.
24. Lightly lubricate the bearings with GM P/N 12378515.
25. Install the reverse gear.
Caution: Refer to Proper Handling of Preheated Components Caution in Service Precautions.
26. If RWD, wearing protective gloves, install the preheated thrust washer on the main shaft.
27. Use the J 44735 and a hammer to ensure the thrust washer is fully and squarely seated.
Caution: Refer to Proper Handling of Preheated Components Caution in Service Precautions.
Important: The main shaft rear bearing for a 4WD vehicle is a sealed bearing.
28. Wearing protective gloves install the preheated main shaft rear bearing on the main shaft. Rotate the bearing while installing to ensure the bearing is fully and squarely seated.
29. If the vehicle is 4WD, install the retaining ring for the main shaft rear bearing. Ensure the retaining ring is fully seated.
30. If the vehicle is RWD, install the vehicle speed sensor reluctor wheel. The reluctor wheel should slide on the mainshaft.
31. Install the 6th gear shift fork and rail.
31.1. The part numbered end goes up on the shift rail.
31.2. Install the shift fork to the 6th gear synchronizer assembly.
31.3. Move the shift interlock plate towards the 1st/reverse position, if necessary.
31.4. Tap the shift rail with a soft-face hammer into the shift fork and the intermediate case.
32. Install the 1st/reverse shift fork and rail.
32.1. The part numbered end goes up on the shift rail.
32.2. Install the shift fork to the 1st/reverse gear synchronizer hub.
32.3. Move the interlock plate towards 6th gear shift rail.
32.4. Tap the shift rail with a soft-face hammer into the shift fork and the intermediate case.
33. Install the NEW roll pins in the 6th gear shift fork (2). A roll pin goes in each hole.
34. Install the NEW roll pins in the 1st/reverse gear shift fork (1). A roll pin goes in each hole.
35. If removed install the shift block on the main shift rail.
35.1. The part numbers on the shift block and the part number on the shift rail face the same direction.
35.2. Install the NEW large diameter roll pin.
35.3. Install the NEW small diameter roll pin with the roll pin split 180° from the large roll pin split.
36. Install the front internal shift lever on the main shift rail.
^ Align the roll pin or lever end, towards the part numbered end of the shift rail.
^ Do not install the roll pins.
37. With the part numbered end pointing up, install the main shift rail.
38. Align the shift block teeth on the main shift rail with the shift interlock plate.
The center tooth on the shift block installs between the two teeth on the shift interlock plate.
39. Position the front internal shift lever to align with the notch in the 2nd/3rd shift rail.
40. Install the NEW roll pins in the internal shift control front lever.
40.1. Install the large diameter roll pin.
40.2. Align the split on the roll pin away from the transmission.
40.3. Install the small diameter roll pin inside of the large diameter roll pin.
40.4. Align the split on the roll pin towards the transmission.
41. Install the internal shift control rear lever on the main shift rail.
42. Align the levers on the internal shift control rear lever with the slots in the 1st/reverse gear shift rail and the 6th gear shift rail.
43. Install the NEW roll pins in the internal shift control rear lever.
43.1. Install the large diameter roll pin.
43.2. Align the split on the roll pin away from the transmission.
43.3. Install the small diameter roll pin inside of the large diameter roll pin.
43.4. Align the split on the roll pin towards the transmission.
44. Install the shift shaft detent plungers and springs.
45. Apply a thin layer of gasket maker GM P/N 12378517 to the shift shaft detent caps.
46. Using an 11 mm (27/64 inch) punch, install the shift shaft detent caps.
47. Shift the transmission into 5th gear in order to lock the input shaft to the mainshaft.
48. Install S-hooks and chain to the intermediate case.
49. Position the front of the front case on boards in order to allow the protrusion of the input shaft.
50. Using a suitable lifting device install the gear assembly to the front case.
^ Lower the gear assembly slowly in order to align the intermediate case dowel pins with the front case.
^ Do not use a sealer at this time.
Notice: Refer to Fastener Notice in Service Precautions.
51. Install the two intermediate to front case bolts.
^ Tighten the intermediate case bolts to 23 Nm (17 ft. lbs.).
52. Use the following procedure in order to measure the countershaft bearing clearance.
52.1. Mount the J 44739 to the intermediate case using the rear case bolts. The J 44739 has three positions for locating the cross-piece. Use the lower position for the countershaft.
52.2. Install the J 26900-12 or the J 29763 in the J 44739.
52.3. Adjust the J 26900-12 or the J 29763 to zero.
52.4. Using a suitable prying tool, lift up the countershaft.
52.5. Record the dial indicator reading. This is the countershaft bearing clearance.
53. Using the following formula, establish the shim thickness required for the countershaft bearing preload:
53.1. Add the mainshaft preload specification 0.02 - 0.09 mm (0.0008 - 0.0035 inch) to the countershaft bearing clearance measurement.
53.2. The total is the shim thickness required under the countershaft bearing race in order to set the bearing preload. Example
^ 1.8 mm (0.070 inch) mainshaft bearing clearance measurement
^ Plus 0.02 - 0.09 mm (0.0008 - 0.0035 inch) countershaft preload specification
^ Equals 1.82 - 1.89 mm (0.070 - 0.074 inch) shim thickness required
54. Use the following procedure in order to measure the main shaft bearing clearance.
54.1. Mount the J 44739 to the intermediate case using the rear case bolts. The J 44739 has three positions for locating the cross-piece. Use the center position for 4WD transmission or top position for RWD transmission.
54.2. Install the J 26900-12 or the J 29763 in the J 44739.
54.3. Adjust the J 26900-12 or the J 29763 to zero.
54.4. Using a suitable prying tool lift up the main shaft.
54.5. Record the dial indicator reading, this is the main shaft bearing clearance measurement.
55. Using the following formula, establish the shim thickness required for the main shaft bearing preload:
55.1. Measure the input shaft bearing oil deflector thickness. Record this measurement.
55.2. Subtract the oil deflector measurement form the mainshaft bearing clearance measurement.
55.3. Add the mainshaft preload specification 0.02 - 0.09 mm (0.0008 - 0.0035 inch).
55.4. The total is the shim thickness required under the input bearing race in order to set the bearing preload. Example 0.50 mm (0.020 inch) oil deflector thickness minus 2.2 mm (0.087 inch) mainshaft bearing clearance measurement equals 1.7 mm (0.067 inch) plus 0.02 - 0.09 mm (0.008 - 0.0035 inch) mainshaft preload specification equals 1.75 mm (0.069 inch) shim thickness required
56. Remove the two bolts retaining the intermediate case to the front case.
57. Using S-hooks, chain and a suitable lifting device, remove the gear assembly.
58. Remove the main shaft front bearing race using the J 44736 (1) and the J 44733 (2).
58.1. Expand the J 44733 (2) to fit securely under the bearing race.
58.2. Align the legs of the J 44733 to rest on the webbing of the case.
58.3. Remove the main shaft front bearing race.
59. Remove the countershaft front bearing race using the J 44736 (1) and the J 44738 (2).
59.1. Install the J 44738 (2) in order for the fingers to fit in the notches in the case.
59.2. Expand the J 44738 (2) to fit securely in the bearing race.
59.3. Align the legs of the J 44736 to rest on the webbing of the case.
59.4. Remove the countershaft front bearing race.
60. Using the J 25070 heat the front case for 10 to 15 minutes.
61. Install the required shims for the countershaft bearing preload.
Important: Install the bearing races with the front case still hot. Do not allow the front case to cool.
62. Install the countershaft front bearing race using the J 8092 (1), J 21465-13 (2) and the J 44745 (3).
63. Install the oil trough.
64. Install the required shims for the mainshaft bearing preload.
65. Install the input shaft gear oil deflector.
66. Install the main shaft front bearing race using the J 8092 (1), J 21465-13 (2) and the J 44746 (3).
67. Allow the front case to cool.
68. Apply a thin layer of gasket maker GM P/N 12378517 to the sealing surface of the front case.
69. Using a suitable lifting device install the gear assembly to the front case.
70. Install the two intermediate case to front case bolts.
^ Tighten the intermediate case bolts to 23 Nm (17 ft. lbs.).
71. Apply a thin layer of gasket maker GM P/N 12378517 to the sealing surface of the rear case.
72. Install the rear case on the intermediate case.
73. Using a soft-face hammer tap down on the rear case to seat on the dowel pins. Do not use the bolts to draw the case together.
74. Install the required brackets and the bolts retaining the rear case.
^ Tighten the rear case bolts in a crossover sequence to 23 Nm (17 ft. lbs.).
75. Apply a thin layer of threadlocker GM P/N 12345382 to the threads of the shift shaft detent sleeve.
76. Install the shift shaft detent plunger and sleeve.
^ Tighten the detent sleeve to 65 Nm (48 ft. lbs.).
77. If the transmission is for a RWD vehicle, install the rear oil seal using the J 44732. The seal installer will install the seal at the correct depth.
78. Lightly lubricate the seal surface with J 36850 or equivalent.
79. If the transmission is for a RWD vehicle, install the propeller shaft yoke.
80. Install the NEW propeller shaft yoke nut.
81. Install the J 8614-01 in order to hold the transmission shaft from rotating.
^ Tighten the NEW propeller shaft yoke nut to 330 Nm (244 ft. lbs.).
82. Install the transmission drain plug and O-ring seal. Ensure the O-ring seal is not damaged.
^ Tighten the drain plug to 35 Nm (26 ft. lbs.).
83. If the lower shift lever requires installation before installing in the vehicle, apply a thin layer of gasket maker GM P/N 12378517 to the sealing surface of the lower shift control lever.
84. Install the lower shift control lever.
85. Install the lower shift control lever bolts.
^ Tighten the lower shift control lever bolts to 23 Nm (17 ft. lbs.).
86. Position the transmission on the transmission bottom.
87. Install the input shaft seal using the J 44731.
88. Shift the transmission through all of the gears ensure proper shifting.
89. Rotate the transmission by the input shaft. There should be a good resistance to turn.