2003 f150, had tranny rebuilt, mech went to jail and I picked up my truck from garage with police escort. Anyway tranny working so so but only with speed sensor on side of tranny disconnected, connected keeps giving me overlimit speed codes. Had it scanned and was told computer thinks truck is going over 100 mph at like 25mph and cuts off. I have been using truck with speed sensor on trannny disconnected but shifts harder than normal and o/d light blinking. Where should I start?

 

You should start by removing the trans, tearing it down, and looking at the drum that the speed sensor is reading. As I remember it the 2003 had six holes for the sensor to read, later models had more holes. So if he used a later drum with more holes then it's going to read REALLY fast.

 

This^
Had this problem when I put a 99 tranny into my 02. Had to use the 02 speed sensor. Using the 99 sensor read wrong.. Or maybe thats backwards?

 

I need to replace my transmission in my 97 a 4r70w. I'm thinking about using an 07 4r75E.
I was told the same thing about the drum 6 holes compared to 24 holes. The first thing I would do is check the tag on your transmission for a model # and a date. There are after market transmission controllers that you could use, if I put in the newer transmission that's what I plan to do.