"I would remove the overdrive solenoid, dissemble, clean and re-install. The overdrive is actuated when the solenoid valve blocks/restricts the transmission fluid return path and raises the pressure to the actuating pistons. Self actuation indicates something is keeping the hydraulic fluid from flowing freely through the solenoid valve in the non-energized state. "

John
Thanks for the response first off!
okie on removing the solenoid, and cleaning it.
The strange thing is it engages just find, just wont
disengage overdrive reliably. Even when I popped it into neutral which would have disengaged the electrical portion of it because of the 4th gear switch.
Is there always current flowing to the overdrive solenoid when OD is on?
or is it momentary to engage the solenoid?

thanks
take care
Luke