Part 1
Transmission Overhaul Part 1
Intermediate One-Way Clutch Replacement
Tools Required
J 26900-6 Dial Caliper
Removal Procedure
1. Inspect the intermediate one-way clutch before disassembly by placing the intermediate brake hub and the intermediate one-way clutch onto the rear of the sun gear input drum, holding the sun gear input drum stationary and rotating the intermediate brake hub.
* The intermediate brake hub should turn freely in a clockwise direction (2) and should not turn in a counterclockwise direction (4).
* If the intermediate brake hub is installed correctly on the sun gear input drum and the intermediate brake hub can be turned counterclockwise, replace the intermediate brake hub and intermediate one-way clutch
Notice: The intermediate one-way clutch should be disassembled for inspection purposes only. If excessive wear or damage is found in any component of the intermediate one-way clutch upon inspection, replace the intermediate brake hub assembly.
2. Remove the rear thrust plate from the intermediate brake hub (1).
3. Remove the intermediate one-way clutch retainers and the sprag assembly from the intermediate brake hub (4).
4. Remove the front planetary ring gear flange snap ring (1) from the front planetary ring gear.
5. Remove the front planetary ring gear flange (2) from the front planetary ring gear (1).
6. Remove the sun gear input drum snap ring (2) from the sun gear at the rear of the sun gear input drum.
7. Remove the sun gear (1) from the sun gear input drum (3).
8. Remove the sun gear snap ring from the sun gear.
9. Clean all components of the front planetary gearset and the sun gear input and dry these components thoroughly.
10. Inspect the following components for excessive wear or damage. Replace the intermediate brake hub assembly as necessary:
* The intermediate one-way clutch outer race
* The retainers
* The sprag assembly
11. Inspect the following components for excessive wear or damage and replace as necessary:
* The front planetary ring gear
* The front planetary carrier pinion gears
* The sun gear
12. Use a J 26900-6 in order to measure the front planetary ring gear flange bushing inside diameter (2).
* The standard front planetary ring gear flange bushing inside diameter should fall within 19.025-19.050 mm (0.7490-0.7500 in).
* If the front planetary ring gear flange bushing inside diameter is greater than 19.050 mm (0.7500 in), replace the front planetary ring gear flange.
13. Use the J 26900-6 in order to measure the sun gear flange bushing inside diameter.
* The standard sun gear flange bushing inside diameter (1) should fall within 22.025-22.046 mm (0.8671-0.8680 in).
* The maximum sun gear flange bushing inside diameter (2) is 22.096 mm (0.8699 in).
* If the sun gear flange bushing inside diameter is greater than specified, replace the sun gear.
14. Use a feeler gage (2) in order to measure the front planetary carrier pinion gear thrust clearance.
* The standard front planetary carrier pinion gear thrust clearance should fall within 0.20-0.50 mm (0.008-0.020 in).
* If the front planetary carrier pinion gear thrust clearance is greater than 0.50 mm (0.020 in), replace the front planetary carrier.
Installation Procedure
1. Install the sun gear snap ring onto the sun gear.
2. Install the sun gear into the sun gear input drum.
3. Install the sun gear input drum snap ring onto the sun gear at the rear of the sun gear input drum.
4. Install the front planetary ring gear flange into the front planetary ring gear; secure with the front planetary ring gear flange snap ring.
5. Install the intermediate one-way clutch sprag assembly and retainers into the intermediate brake hub.
6. Install the rear thrust plate onto the intermediate brake hub.
7. Inspect the intermediate one-way clutch after assembly by placing the intermediate brake hub and intermediate one-way clutch onto the rear of the sun gear input drum, holding the sun gear input drum stationary and rotating the intermediate brake hub.
* The intermediate brake hub should turn freely in a clockwise direction (2) and should not turn in a counterclockwise direction (4).
* If the intermediate brake hub is installed correctly on the sun gear input drum and the intermediate brake hub can be turned counterclockwise, replace the intermediate brake hub and the intermediate one-way clutch.
First Reverse Brake Assembly Replacement
Removal Procedure
1. Remove the two 1st-reverse brake piston seals from the 1st-reverse brake piston.
2. Clean all the 1st-reverse brake components and dry thoroughly.
3. Inspect the 1st-reverse brake discs for excessive wear or damage and replace as necessary.
4. Inspect the 1st-reverse brake piston for cracks or porosity and replace as necessary.
5. Inspect the 1st-reverse brake piston return spring for distortion or weakness and replace as necessary.
Installation Procedure
Install the new 1st-reverse brake piston seals onto the 1st-reverse brake piston.
Second Coast Brake Removal
1. Remove the 1 bolt and the second coast brake apply pipe bracket (2) from the transaxle case (1).
2. Remove the 2nd coast brake apply pipe (1) from the transaxle case (2).
3. Place a reference mark (1) on the 2nd coast brake piston rod (2) where the piston rod meets the transaxle case.
4. Apply 392-785 kPa (57-114 psi) of compressed air into the 2nd coast brake apply passage (2).
5. Measure the distance between the reference mark and the transaxle case using a feeler gage (1) to obtain the 2nd coast brake piston stroke.
* The 2nd coast brake piston stroke should fall within 1.5-3.5 mm (0.059-0.138 in) (3).
* If the 2nd coast brake piston stroke exceeds specification, inspect the 2nd coast brake band for excessive wear or damage.
6. Remove the 2nd coast brake servo cover snap ring (1) from the transaxle case.
Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).
7. Remove the following components from the transaxle case (2) by slowly applying low pressure compressed air into the 2nd coast brake servo apply passage (1):
* The 2nd coast brake servo cover
* The 2nd coast brake piston
* The 2nd coast brake piston outer return spring
8. Remove the forward and direct clutch assemblies (3, 2) from the transaxle case by grasping the input shaft (1) and lifting the shaft upward.
9. Remove the 2nd coast brake band anchor pin (2) from the transaxle case (1).
10. Remove the 2nd coast brake band from the transaxle case (1).
First Reverse Brake Removal
1. Measure the 1st-reverse brake assembly clearance (1) using a feeler gage (2).
* The 1st-reverse brake assembly clearance should fall within 1.060-2.380 mm (0.0417-0.0937 in).
* If the 1st-reverse brake assembly clearance is below 1.060 mm (0.0417 in), inspect the 1st-reverse brake assembly components for excessive wear or damage.
2. Remove the 1st-reverse brake snap ring (1) from the transaxle case.
3. Remove the following components from the transaxle case:
* 1st-reverse brake flange
* Six plates
* Six discs
First Reverse Brake Piston Removal
Tools Required
* J 23327 Clutch Spring Compressor
* J 35683 First and Reverse Brake Piston Compressor
1. Install the J 23327 with a J 35683 and compress the 1st-reverse brake piston return spring until the 1st-reverse brake piston return spring snap ring (2) can be removed.
2. Remove the 1st-reverse brake piston return spring snap ring (1) from the transaxle case.
3. Remove the J 23327 and the J 35683 from the transaxle case.
4. Remove the 1st-reverse brake piston return spring (1) from the transaxle case.
Caution: Refer to Safety Glasses Caution
Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).
5. Remove the 1st-reverse brake piston (1) from the transaxle case by slowly applying low pressure compressed air into the fluid passage (2).
6. Remove the 1st-reverse brake assembly.
Underdrive Clutch Removal
1. Remove the underdrive clutch assembly (1) from the underdrive one-way clutch and the underdrive brake assembly (2).
2. Remove the underdrive clutch thrust washer (2) from the rear of the underdrive clutch drum (1).
3. Remove the underdrive one-way clutch anti-rattle clip (1) from the transaxle case.
4. Remove the underdrive one-way clutch (2) from the transaxle case (1).
Underdrive Brake Removal
Tools Required
* J 7872 Magnetic Base Indicator Set
* J 23327 Clutch Spring Compressor
* J 37282 Underdrive Brake Piston Compressor
1. Use the J 7872 in order to measure the underdrive brake assembly (1) clearance.
2. Apply 392-785 kPa (57-114 psi) of compressed air into the underdrive brake apply passage (2). Measure the underdrive brake assembly clearance.
3. The underdrive brake assembly clearance should fall within 1.070-2.050 mm (0.0421-0.0807 in).
4. If the underdrive brake assembly clearance does not fall within specification, inspect the underdrive brake assembly components for excessive wear or damage.
5. Install a J 23327 with a J 37282 and compress the underdrive brake piston return spring until the underdrive brake piston return spring snap ring (1) can be removed.
6. Remove the underdrive brake piston return spring snap ring (1) from the transaxle case.
7. Remove the J 23327 and the J 37282 from the transaxle case.
8. Remove the underdrive brake flange (2), the three plates (1) and the three discs (3) from the transaxle case.
9. Remove the underdrive brake piston return spring (2) from the transaxle case (1).
10. Remove the two seal rings (1) from the underdrive clutch drum support (2).
Caution: Refer to Safety Glasses Caution
Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).
11. Remove the underdrive brake piston from the transaxle case by slowly applying low pressure compressed air into the underdrive brake apply passage (2).
Torque Converter Housing Removal
Tools Required
* J 26941 Countershaft Bearing and Drive Axle Seal Remover
* J 2619-01 Slide Hammer
1. Remove the 3 bolts and the 3 fluid pipe clamps (1) from the torque converter housing (3).
2. Remove the 2 fluid pipes (2) from the torque converter housing (1).
3. Remove the bolt and the countershaft front roller bearing retainer (3) from the torque converter housing (1).
4. Use the J 26941 with a J 2619-01 in order to remove the countershaft front roller bearing (1) from the torque converter housing (2).
5. Remove the countershaft lubrication seal (2) from the countershaft front roller bearing bore (1).
6. Use the J 26941 with a J 2619-01 in order to remove the right drive axle shaft fluid seal from the torque converter housing.
7. Use the J 26941 with a J 2619-01 in order to remove the following components from the torque converter housing (1):
* The right differential side bearing race (2)
* The right differential selective shim (3)
8. Clean the sealant from the torque converter housing-to-transaxle case mating surfaces.
Case Assembly Cleaning
1. Thoroughly clean the case components with solvent.
2. Air dry the components.
3. DO NOT wipe the components with cloths or rags.
Second Coast Brake Replacement
Tools Required
J 26900-6 Dial Caliper
Removal Procedure
1. Remove the two 2nd coast brake servo cover seals from the 2nd coast brake servo cover.
2. Remove the seal (2) from the 2nd coast brake piston (1).
3. Remove the following components from the 2nd coast brake piston:
* The 2nd coast brake piston rod
* The 2nd coast brake piston rod E-ring
4. Remove the following components from the 2nd coast brake piston rod (1):
* The 2nd coast brake inner return spring (3)
* The 2nd coast inner return spring seat (2)
5. Clean all of the 2nd coast brake components and dry the components thoroughly.
6. Inspect the following components for cracks or porosity. Replace the components as necessary:
* The 2nd coast brake servo cover
* The 2nd coast brake piston (4)
7. Inspect the following components for distortion or excessive wear. Replace the components as necessary:
* The 2nd coast brake inner return spring
* The 2nd coast brake outer return spring
8. Inspect the 2nd coast brake band lining for cracks or excessive wear and replace as necessary. If the 2nd coast brake piston stroke is not within specification, measure the 2nd coast brake piston rod length to determine a suitable replacement 2nd coast brake piston rod.
9. Use the J 26900-6 in order to measure the 2nd coast brake piston rod length.
10. If the 2nd coast brake band appears to exhibit little or no wear, select one of the two different size piston rod lengths available in order to lengthen or shorten the 2nd coast brake piston rod stroke until the stroke is within specification.
There are two 2nd coast brake piston rod lengths available:
* 72.90 mm (2.870 in)
* 71.40 mm (2.811 in)
Installation Procedure
1. Install the following components onto the 2nd coast brake piston rod (1):
* The 2nd coast brake inner return spring seat (2)
* The 2nd coast brake inner return spring (3)
2. Install the 2nd coast brake servo piston rod into the 2nd coast brake piston (4). Secure the servo piston rod with one E-ring.
3. Install the new 2nd coast brake piston seal onto the 2nd coast brake piston.
4. Install the 2 new 2nd coast brake servo cover seals onto the 2nd coast brake servo cover.
Underdrive Clutch Assembly Replacement
Tools Required
* J 7872 Magnetic Base Indicator Set
* J 23327 Clutch Spring Compressor
* J 37279 Clutch Spring Compressor
* J 26900-6 Dial Caliper
* J 36850 Transjel(R) Lubricant
Removal Procedure
1. Inspect the underdrive one-way clutch before disassembly by placing the underdrive one-way clutch onto the rear of the underdrive clutch drum, holding the underdrive clutch drum stationary and rotating the underdrive one-way clutch.
2. The underdrive one-way clutch should turn freely in a counterclockwise direction (2) and should not turn in a clockwise direction (3). If the underdrive one-way clutch is installed correctly on the underdrive clutch drum and the underdrive one-way clutch can be turned clockwise, replace the underdrive one-way clutch.
3. Use a J 7872 to measure the underdrive clutch (1) piston stroke before disassembly.
* Temporarily install the old underdrive clutch drum support seal rings on the underdrive clutch drum support in the transaxle case.
* Place the underdrive clutch drum on the underdrive clutch drum support in the transaxle case and the J 7872 plunger on the underdrive clutch piston.
4. Apply 392-785 kPa (57-114 psi) of compressed air into the underdrive clutch apply passage (1) in the transaxle case and observe the J 7872 .
* The standard underdrive clutch piston stroke should fall within 1.500-1.900 mm (0.0590-0.0748 in).
* If the underdrive clutch piston stroke is greater or less than specified, inspect all underdrive clutch components for excessive wear.
Caution: Refer to Safety Glasses Caution
Notice: The underdrive one-way clutch should be disassembled for inspection purposes only. If excessive wear or damage is found in any component of the underdrive one-way clutch upon inspection, replace the underdrive one-way clutch as an assembly.
5. Remove the rear thrust plate (2) from the underdrive one-way clutch outer race (1).
6. Remove the underdrive one-way clutch retainers (2, 4) and the sprag assembly (3) from the underdrive one-way clutch outer race.
7. Remove the underdrive clutch snap ring (2) from the underdrive clutch drum (1).
8. Remove the following components from the underdrive clutch drum (1):
* The underdrive clutch flange
* The 4 discs
* The 4 plates
9. Use a J 23327 with a J 37279 to remove the underdrive clutch piston return spring snap ring (1) from the underdrive piston return spring (2).
10. Remove the following components from the underdrive clutch piston:
* The underdrive clutch piston return spring (1)
* The underdrive clutch piston return spring plate (2)
Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).
11. Remove the underdrive clutch piston from the underdrive clutch drum by placing the underdrive clutch drum on the underdrive clutch drum support in the transaxle case and applying low pressure compressed air into the underdrive clutch apply passage (1) in the transaxle case (2).
12. Remove the underdrive clutch drum from the underdrive clutch drum support in the transaxle case.
13. Inspect the following components for excessive wear or damage and replace the underdrive one-way clutch assembly as necessary:
* The underdrive one-way clutch sprag assembly
* The underdrive one-way clutch outer race
14. Inspect the underdrive clutch discs for excessive wear or damage and replace as necessary.
15. Inspect the underdrive clutch piston for cracks or porosity and replace as necessary.
16. Inspect the underdrive clutch piston check ball operation by applying compressed air into the working and release sides of the underdrive clutch piston.
17. There must be no air leakage on the working side and air must pass freely through the release side. If these conditions do not exist, replace the underdrive clutch piston.
18. Inspect the underdrive clutch piston return spring for distortion or weakness and replace as necessary.
19. Use a J 26900-6 to measure the inside diameter of the front and rear underdrive clutch flange (3) bushings.
* The standard underdrive clutch flange bushing diameter should measure within the following parameters:
- Front (1) 46.500-46.525 mm (1.8307-1.8316 in).
- Rear (2) 55.000-55.030 mm (2.1653-2.1665 in).
* The maximum inside diameter of the underdrive clutch bushing should measure within the following parameters:
- Front 46.570 mm (1.8334 in)
- Rear 55.080 mm (2.1685 in)
If the inside diameter of the underdrive clutch bushings are greater than specified, replace the underdrive clutch drum.
Installation Procedure
Caution: Refer to Safety Glasses Caution
Notice: When installing new clutch discs in the 1st-reverse brake, forward clutch or direct clutch assemblies, the new clutch discs MUST be soaked in Dexron(R) - III automatic transmission fluid GM P/N 12341643, or equivalent, two hours prior to installation. This causes the clutch material on the discs to permeate with fluid which will aid in ease of assembly and prevent clutch overheating on first time engagement.
Important: When using compressed air to remove components, air pressure should not exceed 98 kPa (14 psi).
1. Install the two underdrive clutch piston seals (1) onto the underdrive clutch piston (2).
2. Apply J 36850 to the new underdrive clutch piston seals.
3. Install the underdrive clutch piston (1) into the underdrive clutch drum (2).
4. Install the underdrive clutch piston return spring and the underdrive clutch piston return spring into the underdrive clutch piston.
5. Use a J 23327 with a J 37279 to install the underdrive clutch piston return spring snap ring onto the underdrive piston return spring (2).
6. Install the 4 discs, 4 plates and underdrive clutch flange into the underdrive clutch drum (1) in the following order:
1. 1 plate
2. 1 disc
3. 1 plate
4. 1 disc
5. 1 plate
6. 1 disc
7. 1 plate
8. 1 disc
Important: The underdrive clutch flange must be installed with the flat side facing down and the stepped portion facing upwards.
7. Install the flange.
8. Install the underdrive clutch snap ring into the underdrive clutch drum.
9. Install the underdrive one-way clutch sprag assembly (3) and retainers (2, 4) into the underdrive one-way clutch outer race (5).
10. Install the rear thrust plate (2) onto the underdrive one-way clutch outer race (1).
11. Use a J 7872 to measure the underdrive clutch piston stroke after assembly.
12. Place the underdrive clutch drum (1) on the underdrive clutch drum support in the transaxle case and the J 7872 plunger on the underdrive clutch piston.
13. Apply 392-785 kPa (57-114 psi) of compressed air into the underdrive clutch apply passage (1) in the transaxle case and observe the J 7872
* The standard underdrive clutch piston stroke should fall within 1.500-1.900 mm (0.0590- 0.0748 in).
* If the underdrive clutch piston stroke does not fall within specification, select one of the two following underdrive clutch flange sizes to bring the underdrive clutch piston stroke within specification:
- 2.040 mm (0.0803 in)
- 2.400 mm (0.0945 in)
* Remove the old underdrive clutch drum support seal rings from the underdrive clutch drum support.
14. Inspect the underdrive one-way clutch after assembly by placing the underdrive one-way clutch onto the rear of the underdrive clutch drum, holding the underdrive clutch drum stationary and rotating the underdrive one-way clutch.
* The underdrive one-way clutch (1) should turn freely in a counterclockwise direction (2) and should not turn in a clockwise direction (3).
* If the underdrive one-way clutch is installed correctly on the underdrive clutch drum and the underdrive one-way clutch can be turned clockwise, replace the underdrive one-way clutch.