Yesterday the E40D tranny on my 1990 F350 with 7.5L 4x4 started shifting at a much higher rpm range and wouldn't go into overdrive until 50mph and the torque converter wouldn't go into lock up. I'm guessing this is a sensor also; any help on this appreciated.

 

Start by pulling the codes. I suspect a faulty TPS.

 

A couple years ago I had this same exact thing happen on my 92' F150 with same tranny and a 5.8 engine; changed the TPS and some other sensors and items and didn't make any difference. So I just put up with it on that one because it did not do it very often

 

Start by checking for error codes. It's pointless to guess.

 

" Another F350 issue" as a title is more than a little vague. You might get more attention with a better title describing what is wrong.