Oil cross leakage at a worn accumulator piston bore pin.
The oversized accumulator pin allows the piston pin bore to be reamed to restore hydraulic integrity.
A burned or complete failure of the direct clutch on the THM 350 transmission can be created by accumulator cross leaks. A drivability complaint of a long slide on the 2-3 shift can result from excessive piston wear. These complaints can be caused by oil cross leakage between the piston and pin in the front accumulator assembly located in the valve body. Excess wear is due to the constant oscillating motion of the the aluminum accumulator piston on the steel pin. The problem occurs when direct clutch oil and intermediate circuits cross leak. In second gear a cross leak may drag the direct clutch and create premature failure. Starter kit 34105-02K contains 10 pins, 10 retaining rings, and 1 reamer.
Contact a Sonnax Parts Distributor.