28. Underdrive Brake Assembly Installation

Underdrive Brake Assembly Installation

Tools Required
^ J36850 Transjel- Lubricant
^ J23327Clutch Spring Compressor
^ J37282 Piston Brake Compressor





Important: When installing new clutch discs in the 1st-reverse brake, the underdrive brake, the underdrive clutch, the intermediate brake, the forward clutch or the direct clutch assemblies, the new clutch discs MUST be soaked in Dexron III Automatic Transmission Fluid GM P/N 12346143 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.
1. Install the 2 new seal rings onto the underdrive clutch drum support (2).
2. Apply J36850 in order to the two new underdrive clutch drum support seal rings (3).
3. Apply J36850 in order to the two new underdrive brake piston seals.





4. Install the underdrive brake piston (1) into the transaxle case with the cup side facing upwards.





5. Install the underdrive brake piston return spring (1) into the transaxle case.





6. Install the underdrive brake flange (2), three plates (3) and three discs (1) into the transaxle case in the following order:
^ Plate
^ Disc
^ Plate
^ Disc
^ Plate
^ Disc
^ Flange





7. Align the inner teeth of the underdrive brake discs (2).
8. Install the J23327 with the J37282 into the transaxle case and compress the underdrive brake piston return spring until the underdrive brake piston return spring snap ring can be installed.
9. Install the underdrive brake snap ring into the transaxle case.
10. Remove the J37282 and the J23327 from the transaxle case.





11. Measure the underdrive brake assembly (1) using a J7872. Apply 392 - 785 kPa (57 - 114 psi) of compressed air into the underdrive brake apply passage (2).
^ Verify that the underdrive brake assembly clearance falls within 1.07 - 2.05 mm (0.0421 - 0.0807 inch).
^ If the underdrive brake assembly clearance does not fall within specification, inspect the underdrive brake assembly for excessive wear.