March 07, 2016
Ford CFT30 transmissions may have difficulty properly controlling the primary pulley, resulting in ratio errors, ratio codes, and inability to access higher ratios. These troubles can often be traced to excess wear at the primary pulley boost valve/sleeve assembly. This deterioration allows critical control pressure to exhaust, preventing full control of the pulley. Installing Sonnax primary pulley boost valve kit 33740-01K returns hydraulic integrity to the circuit for renewed control under all operating conditions.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.