Ford AXOD, AXOD-E, AX4S & AX4N Transmission Superior Boost Valve & Sleeve This Boost Valve & Sleeve Kit from Superior will improve all AXOD, AXODE, AX4S & AX4N Transmissions. This problem solver deals with these problems: Pressure exhausting out of valve body & worn out boost valve. As AXOD transmissions rack up higher mileage they begin showing the same signs of boost valve wear that are commonly seen in the AXOD-E. The Superior AXOD Boost Valve and Sleeve addresses this problem by offering a CASE HARDENED STEEL boost valve and sleeve with O-ring to help prevent loss of pressure rise and intermittent shift problems. This Boost Valve and Sleeve kit will service AXOD, AXODE, AX4S and AX4N transmissions.