September 30, 2005
Uncontrollable throttle pressure due to oil loss is a common complaint in vehicles with Ford AOD transmissions. This results in low line pressure and poor throttle and shift timing adjustments. The hardened steel throttle valve plug continuously reciprocates within the aluminum throttle valve sleeve, wearing the inside diameter of the sleeve. This wear allows throttle valve feed oil to leak past the plug and exhaust, resulting in poor line rise. This excessive leakage can be eliminated by installing Sonnax throttle valve plug kit 76989K.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.