I'm having a problem with my tranny, I had it rebuilt a couple of years ago and hardly ever drove it. A few months after the rebuild it started shifting hard and really grinding when put in reverse (sometimes). The tech seemed to think it was either an electrical or pump/valve issue. He was going to check it out but kept putting me off, finally I moved and didn't get it done.
However on the move, pulling a trailer, I noticed something very strange. This is what I need help with; Driving at highway speeds, pulling a trailer, in OD, I could put on left turn signal and it would shift down into drive (didn't do it with right turn signal). Also shifted down when I put on hazards. Or if I was in Drive the left turn signal caused a change in the torque converter lockout(RPM's changed).
So here's my theory, Maybe if I change the steering column out with a good one( BTW the cruise isn't working among other things that may or may not matter) that it might fix or change a possible electrical issue that is causing the tranny problem.

 

Before you go randomly changing parts around like steering columns check all the wiring and lights on the vehicle. Have you put any aftermarket exterior lights on? Do all your brake lights and turn signals work? Also look for loose wires or broken grounds. It seems like you're looking at two different problems, the grinding in reverse is probably not related to the shifting and torque converter unlocking. As for the grinding, you're probably going to have to take it to a pro, especially if you had it rebuilt. You really should have taken it to the guy who rebuilt it, I don't know why you let him put you off like that, you paid the money you should get a tranny that works. But that's also a sign that you took it to a crooked/incompetent mechanic, which is also your bad for not doing your homework on your mechanic before giving him a lot of your money.

 

if ya got led tail light bulbs that may be your problem-check threads! do a search-and you should not tow in over drive! the e4od has a multitude of electric problems-don't think it's just the trans -it's an electronic shift transmission!pull the codes!!

 

also what year is your truck would help to diagnose the problem!

 

1994 is the model of the truck, I don't have any extra lights or mods on the truck.
The transmission mechanic works for the ford dealer in Muskogee Oklahoma and has been there many years. The mechanic that referred me to him worked there also and was the one that took it out and put it back in and was also the one to put me off about getting it redone.
Thanks for whatever input I've received, I am only hoping for a fairly easy fix instead of another rebuild, but I really know better. Also, I know I'm not supposed to tow in OD and did not do it for very long.

 

I am betting it was unlocking the converter, not downshifting to 3rd. If so, that would mean your turn signal is bleeding over to the brake light circuit.