Well i have a question ,does the trany flush work for the 1990 birds as well or not ,we have the O.D trany and it seems to shift hard sometimes,or would the shift kit improvments work better ?

Fords overdrive tranny is not a performance piece. If you are haveing slipping issues a flush will shorten the life of a tranny that is already on its way out. Shift improvements???? If the tranny shop you go to is worth its weight they should be able to give you what you want. I can tell you there are kits avalible for your tranny. I am a certified tranny specialist and have improved the AOD. Even with a performance overhaul it is a very weak tranny.

Hey, thanks for the info. I'll hold off on the flush. I'm not really looking for performance out this car I just want a nice car that is reasonable on gas. The news about this variety of tranny being weak is disheartening. <br>Can you answer me why it isn't a good idea to flush if the tranny has trouble? It's not like a blood transfusion I take it? ...

Why its not a good Idea to do a tranny flush on a slipping tranny is because the new tranny fluid is more acidic than what is in the tranny. What this does is it finishes off what is left of the paper cluch packs. It shortens the life of the tanny that is already on its way out!