The reverse servo bore found on the case of listed Ford transmissions can become scored due to repeated oscillation of the reverse servo piston within the bore during normal operation. Once this bore is damaged, the case must be scrapped. Install the Sonnax reverse servo sleeve kit 56532-01K to refurbish the case bore. The drop-in Zip Valve™ installs quickly and easily.
Instructions are included for machining the servo piston assembly by simply turning the smaller piston journal 1/16" smaller.