Underdrive Clutch

UNDERDRIVE CLUTCH

- Tools Required
- KM-698 Spring Compressor

Disassembly Procedure





1. Remove the thrust washer.

WARNING: USE CAUTION WHEN REMOVING SNAP RINGS OR PERSONAL INJURY MAY RESULT.





2. Carefully remove the snap ring.





3. Remove the underdrive clutch pack.





4. Position spring compressor KM-698 on the clutch piston return spring. Using a press, compress the springs, then remove the snap ring from the groove.





5. Remove the snap ring and the clutch piston return spring.





6. Install the underdrive drum into the transaxle case.

WARNING: USE CAUTION WHEN REMOVING COMPONENTS WITH COMPRESSED AIR OR PERSONAL INJURY MAY RESULT.

Notice: If the piston does not come out completely, use needle-nose pliers to remove.





7. Apply 57 psi (396 kPa) of compressed air into the oil passage to remove the underdrive clutch piston.





8. Remove the underdrive clutch piston.





9. Remove and discard the underdrive clutch piston O-rings.

Notice: Check the steel and friction plates for wear or damage. Replace as necessary.

Notice: New clutch plates should be soaked in TOTAL FLUID HX for two hours before being assembled.





10. Inspect the clutch steel and friction plate surfaces.

WARNING: USE CAUTION WHEN CHECKING COMPONENTS WITH COMPRESSED AIR OR PERSONAL INJURY MAY RESULT.





11. Inspect the underdrive clutch piston.
- Check that the valve does not leak by applying low-pressure compressed air.





12. Inspect the underdrive drum.
- Using a dial indicator, measure the inner diameter of the underdrive drum bushing. Measure the bushing at three different places and calculate the average. If it is greater than the maximum, replace the underdrive drum.





Underdrive Drum Table

Assembly Procedure
1. Clean the components using a clean, high-quality parts cleaning solvent and use compressed air to dry all parts. Inspect all parts for damage or wear.





2. Install new underdrive clutch piston O-rings.

Notice: Apply TOTAL FLUID HX to the new underdrive clutch piston O-rings and the drum seal area.

Notice: Seat the piston by pushing evenly around the circumference of the piston, being careful not to damage the outer seal.





3. Install the underdrive clutch piston into the underdrive drum.





4. Install the clutch piston return spring on the underdrive piston.





5. Position spring compressor KM-698 on the clutch piston return spring. Using a press, compress the springs, then install the snap ring into the groove.





6. Install the underdrive clutch pack and the clutch pressure plate.
- The installation order is: steel-friction-steel-friction-steel-friction-steel-friction
- Install the pressure plate with the flat end facing upward.





7. Install the snap ring into the groove.





8. Check the underdrive clutch operation.
- Install the underdrive clutch assembly into the transaxle case.
- Install a dial indicator.

WARNING: USE CAUTION WHEN CHECKING COMPONENTS WITH COMPRESSED AIR OR PERSONAL INJURY MAY RESULT.





9. Apply 57 psi (396 kPa) of compressed air into the oil passage shown. Measure the underdrive clutch piston stroke.
- The piston stroke is 0.060 - 0.074 inch (1.52 - 1.890 mm). The clutch should make a solid apply sound, with no whistle or sign of leaks.





10. Install the one-way clutch onto the underdrive clutch drum.





11. Verify the operation of the one-way clutch. While holding the outer race, turn the underdrive clutch. The underdrive clutch should rotate smoothly when turned counterclockwise and locks when turned clockwise.