Vehicles with a Ford AOD transmission often have shift timing complaints due to governor or accumulator oil circuit leakage caused by leaking valve end plugs in the valve body. Most AOD valve assemblies are designed with an end plug to help retain the line-up and seal the circuitry. As these end plugs wear, circuit oil is lost and affects shift timing. Installing Sonnax O-ringed end plug kit 76999-MED can eliminate this excessive leakage. Replacement plugs are included for the following valve applications: 1-2 shift, 2-3 shift and 3-4 shift (plug or sleeve). Plugs have been manufactured from high-quality aluminum designed to resist wear. O-ring on the outside diameter prevents leakage between the plug and the valve body. Plugs have a standard 8-32 UNC threaded hole for assistance in installation and removal. O-ringed plugs are more durable than knurling the O.D. of the original plug Contents End Plugs (3) Medium O-Rings (6) 3 Extra