I have a manual for the car.It says Dexron3 so I use it.The overdrive isn't working.I checked the wiring from fuse to relay and checked relay all was ok.Today I checked the wiring from relay down through the shifter all the way to where it goes through top side of body.No probs there.I guess when I get a chance I will have to check wiring underneath and solenoid.It is funny how it went out just like the people with the relay prob had.Working fine then intermittent then gone.The only other prob I have with Trans. is rear seal leak.I have to check it every week to keep it full.I thought this might be some of the prob but,It was leaking way before the overdrive quit working.I have made sure to keep it full.The only reason I haven't fixed seal is the 2 types of Trans.take different seals.I thought I might get both and use the 1 that fits.Thx again.