Common problems in Ford 4R70E, 4R70W, 4R75E and 4R75W transmissions include a burned overdrive band, loss of 4th Gear, and/or a 4-3-Neutral shift pattern. These problems can be caused by wear at the innermost diameter of the overdrive servo regulator valve due to constant oscillation. Excess wear allows valuable regulated overdrive oil to leak, preventing proper regulation of the overdrive servo. Sonnax oversized overdrive servo regulator valve kit 76948-59K maintains critical tolerances that re-establish the hydraulic integrity of the 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.