I just picked up my first Cummins. 1996 Cummins 12 Valve with 233k Miles. Mechanically sound Body is hell. But i bought a southern 96 1500 for the body im about 7grand into this project, Well i was driving the cummins home from work today, Stopped at a light took off fine got to about 45-50Mph It didnt feel like the trans slipped, Felt more like it just changed gears my rpms went a high, More so it felt like i hit the OD button the dash then it went back to normal and my rpms went back down, It did this twice in a row then was fine for the rest of the 25min drive home. I even messed with it driving, Shifting it in and out slow speed high speed, I got on it hard. I know these 12v's dont have much Nut off the line. i just dont want to put all this work into changing the bodys over and have my tranny go.

 

That happens to my truck a few times a year. For some reason it shifts out of OD on it's own, just like if I pushed the OD button. I've heard it happen to other people too. Personally I don't think it's a trans problem, I think it's a sensor or wiring problem.

 

butt the trans will go once you bump the power up some, its a 47RE! You will totally want to spend $1,500 on a new torque converter and valve body.

 

I have a'96 I bought from my father a few years ago. Only recently did I begin driving it every day. I have noticed the trans shifts weird when it's cold outside. Mine goes into OD just above 45 mph. When it's really cold, it'll go into OD, but the least amount of throttle will pop it back out, like on a very gentle incline. I googled the issue, and some said there is a sensor in the trans pan that will start to act up over time and can be the culprit.

 

That happens to me to with my 94. You're going along fine and the OD kicks out. The light on the button is on and everything. I just hit the switch and keep going. As another person said it happens about once or twice a year.

 

It might be the wires going up the steering column for the shifter button that are broke.. Mine busted right underneath the plastic cover by the dash.. I resolved it with a horn button on the dash insted of trying to piece them tiny 2 wires back together ..