This problem started about two months ago while plowing a parking lot. The T/C keeps randomly locking up and causes truck to stall at low speeds. Happens off an on. I went 3 weeks with out problems, only way to avoid it is to drive in 2nd. At speeds greater than 30mph I can shift it into drive but need to turn off the od button because it sometimes shifts into od at a very low speeds. Now that i think of it, i think the main problem is that the truck just starts upshifting at very low speeds when it shouldn't. What's going on here? Another thing, a few times i noticed the speedo jumping around a little.
I need to get this fixed asap! Tranny filter is probably due? 20k on rebuilt???

 

I'd call Dave in a heart beat and ask him. We'll guess, he'll know.

 

When mine did that it was the trans speed sensor.