This is a good used original genuine transmission vacuum modulator valve with adjustment key and cap. Failure of this part can lead to harsh or jerking shifts and in some cases prevent the transmission from shifting into 4th gear. There are other things that can cause problems with poor shifting, so there is no guarantee this new part will fix them. This is a good place to start. Kent thoroughly inspected this part and benched tested it after installing a new cap o-ring.
Be sure to confirm you existing modulator is the same color before ordering.The modulator is located on the right rear side of the transmission. A vacuum line coming from the engine compartment is plugged into the nipple on the cap. A loose vacuum connection or failure of the valve diaphragm causes hard or abrupt shifting. Please inspect your valve before ordering this replacement. Modulator pressure should be checked any time you are debugging shift problems. It must be checked and adjusted when installing a replacement moduator. NO instructions are included with this part.