My 1st post, take it easy on me. 94 dtd 42rh tc locking an unlocking & sometimes shifts from unlocked 4 to 3 at speed. Running pot in place of tps, so tps is ruled out, waiting on noise filter for tc lock/unlock prob. any ideas as to my prob. Oh yea trans rebuilt 1700 miles ago.

 

when you are driving will it unlock and then down shift and then does your trans temp light come on because i had the same problem for years and finialy figured out that my trans temp sender was loose so i put little pices of wire in the female plug and has worked perfect. i did the tps,all of the grounds, TC lockup switch, all of the transmission mods and turns out i fixed it for free
well now i have a better tranny anaway. hope this helps.

 

I had the same problem with my 94. Went with the potentiometer and added a noise filter. Problem came back. Put in a new TPS and problem cured.

 

Thank yall' for your help. I think I just might have it under control now, finaly enjoyable to drive. Thanks again to everyone who responded. Bye till next problem arisses.