So the transmission in my 97 7.3 F250 was having trouble shifting into over drive and was holding gears too long. I took it to the transmission shop and they rebuilt my trans and replaced all the worn out parts. I got it back when they were done and it seemed they had done nothing to it. I took it back and they had me pick it up after test driving it because it was throwing zero codes and they claimed it was an "engine performance" issue. So what it is doing is it gets into third gear and instead of locking in, it revs up some (near 2400rpm) then resumes to normal once I let off the throttle. In order for it to shift into overdrive I have to be going between 55-60 (my old shift point was 45) and will only engage into overdrive when I'm giving half throttle or more and no matter what speed I am doing above 55-60 , the minute I let off the throttle the slightest it downshifts and revs to over 2000 rpm. Any help is appreciated as to what it may be. Thanks.