My Firebird has a 700R4, 3.42 in back (if it matters) and a 2.8 needing a tune-up (when I get a round TUIT). When I place it in OD after a one-minute warm-up period, it won't engage. The tranny only decides to go into a forward gear when I place it in D. Someone suggested that the valve passages are dirty and I'm not getting enough cold fluid through it to engage gears. Fair enough. My next problem is this: After driving the car for a while, I can stick it back in OD and it will stay in gear, and putting it in OD when it's nice and warm (from Neutral) will engage gears. However, the car has very little power going to the wheels when in OD as compared to D - it feels like the transmission is slipping or something. I don't hear any wierd noises, no grinding or whatnot - it just seems to be slipping. Do I need a bit more than a flush-out?

 

A flush may or may not knock loose the blockage. Chances are it will just block a different passage if it is knocked loose thou. I would replace/rebuild the valvebody and posibly the entire trans if its also gunked up.

 

The fact that the fluid isn't the healthiest color doesn't help either... I wanted a project car, I got it.