This kit does not recalibrate shift timing or allow gas and diesel valve body interchange.
Heavy-duty vehicles with Ford C6 transmissions often display poor line rise, which results in erratic shift timing, Reverse shudder or direct clutch failure. This can be caused by excess wear at the inside diameter of the boost sleeve. This wear allows oil to leak past the boost valve to exhaust, resulting in poor or no line rise. The outside diameter of the boost sleeve may allow leakage through the valve body, which results in insufficient line rise. Recover the hydraulic integrity of the boost circuit and restore proper line rise by installing Sonnax diesel-ratio boost valve kit 36946-02K.
A number of boost valve kits are available for this unit:
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.