The Manual Valve
The manual valve directs line pressure to the circuit selected by the gear selector. It is connected mechanically to the gear selector by the shift cable. This connection is often adjustable. If incorrectly adjusted, the manual valve will leak line pressure into the wrong circuit.
The vehicle may have a slight vehicle creep when the transmission is in neutral. This drag causes damage and overheating of the transmission's clutch. Inspect the shift cable and linkage adjustment; adjust if necessary. This adjustment is a matter of safety. Always refer to the manufacturer's manual and look for any TSB's before adjusting the linkage.