So I have a 97 7.3 with the E4OD and it had a bad trans when I bought it. It worked fine for about an hour then after that it wouldn’t go past second until you let it cool down. I eventually put a remanned transmission in it and it worked great for a few months until it started going into limp mode and the OD light would flash. I pulled the code and every time it was the speed sensor. I chased it for months replacing the sensor in the diff, the pigtail for it, the tone ring in the rear end, even pulled the speedometer and had the whole computer rebuilt and tested. Only thing I haven’t replaced is the actual wires themselves but I looked everywhere and found nothing wrong with them. I still am having the issue and it’ll just randomly downshift while cruising and if I smack the dash it goes back to normal and a lot of times will get stuck in lockup so if I take off in first it feels like I’m taking off in third and the truck bogs and jerks but if I shut it off and start it back up it’s fine. My turn signals also quit working so I put a whole new multi function switch in and now I noticed when the trans downshifts it cuts out my turn signals for a second or two. Not sure if they’re related. Any advice? I’m pretty lost at this point

 

Hitting dash. Hmm. I'm thinking ground strap behind kick panels corroded. Under cab is some ground straps that get rusty too.
Ever happen with cruise control on?

 

It used to that’s how I would know it was about to start acting up. I would be set in cruise and it would randomly shut the cruise off and I knew it was about to start shifting weird. Honestly haven’t used cruise in a while but I’ll mess around with it and check out those grounds too