The K1 apply boost valve assembly in Aisin Seiki AS66RC and AS69RC transmissions aids in positioning the inboard K1 apply control valve to apply the K1 clutch in 1st through 4th Gears. As the sleeve oscillates from vibrational forces and the valve strokes over time, wear on these OE parts occurs, resulting in the loss of proper hydraulic control of the clutch pack. This can cause delayed forward shifts, forward slip and coast down clunk. Installing Sonnax drop-in K1 apply boost valve kit 122740-29K will restore the normal shift operation by re-establishing the proper hydraulic integrity of the K1 circuit.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.