I just bought a 96 150 4x4 4.9L auto with reverse only forward gears dont even act like they want to engage. Do I go straight for a replacement tranny?

 

That's up to you. Which trans is it? If you don't know, post the TRANS code from the door sticker. I'm guessing it's E which is the E4OD.

The easiest would be to get that one fixed, but it might not be the cheapest or quickest. It would be quicker to get a reman with a warranty, but that's probably the most expensive fix. You could risk a used trans, which would be the cheapest but probably not the most reliable. Another option is to swap a different trans in - like an AOD (if you want another slushbox) or if you want a stick, the ZF (expensive), the Mazda M5OD-R2 (light-duty), or the NP 435 (heavy-duty but no OD).

It's up to you.

 

E4OD I want the fastest fix. I bought the truck for my construction company and need it on the road. Any recomended sites for reman trans without me getting hosed?

 

I wouldn't buy a reman trans thru the net - if something happens, you're stuck. Find a local shop that you trust, or at least one that will stand behind its warranty (the Ford dealer?).