A/T - A140 Slips or No Reverse
Date: 1996Technical Bulletin # 340
Transmission:
A14O
Subject:
Slips or no reverse
Application:
Toyota
A14O
Slips in Reverse or No Reverse
A condition of slipping in reverse, or no reverse is usually caused by a failure in the direct (C2), low/reverse CB3) or overrun (CO) clutch. The most common of these clutches to fail is the CO. The operation of this clutch can be checked easily in the vehicle.
[Step 1] Remove the overdrive housing.
[Step 2] Remove the overdrive sprag, then install it backward.
[Step 3] Assemble the overdrive assembly including the housing.
If reverse now works, the problem is with the operation of the CO clutch. The components to check include the sealing rings, overdrive clutch apply seal, piston seals, CO accumulator seals or a mismatch between the drum and planet (refer to bulletin number 42).
NOTE:
This information is based on the fact that all forward functions are okay and line pressure in reverse in normal (i.e. 77-172 psi at idle, 2O5-239 psi at full TV,1200 rpm).