Check for a stored DTC, and check for loose connectors.

Inspect the clearance between the forward clutch end-plate and the top disc. If the clearance is out of tolerance, replace the forward clutch assembly.

Inspect the input shaft assembly for wear and damage. If the input shaft is worn or damaged, replace it and also check the related part of the input shaft assembly for wear and damage.

Inspect the reverse brake piston and the O-rings. Check the spring retainer for wear and damage. Inspect the clearance between the brake end-plate and the top disc. If the clearance is out of tolerance, inspect the brake discs and plates for wear and damage. If the discs and plates are worn or damaged, replace them as a set. If they are OK, adjust the clearance with the brake end-plate.

Inspect the torque converter assembly for wear and damage. If the torque converter assembly is worn or damaged, replace it as an assembly.