In listed Ford and ZF6 transmissions, clutch C is applied in 2nd and 6th Gears. As the clutch C regulator valve oscillates and strokes over time, bore deterioration results, allowing pressure loss that prevents proper hydraulic control of the clutch. This can cause slipping, ratio codes, poor shift quality in 2nd and 6th Gears as well as clutch C failure.
Reconditioning the bore and installing Sonnax oversized clutch C regulator valve 95740-40K restores normal shift action and clutch control for revived Forward operation.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.