Engine/Transmission (1994 - 1998) auto transmission downshift

[RVPILOT]

i have been having a problem of sudden downshifting. trans rebuilt in July 2011. in Sep2012 it suddendly started to downshift to 3rd. and then go back to OD and then lockup. It seems like it only does this when in lockup, the sequence is like this : at about 62 M P H goes out of lockup into overdrive and then to 3rd and then back int O D and lockup this takesplace in about 3 sec's.

it seems to do it only while in lockup and only after driving for a 100 miles or more. tried different things

like replacing t p s, speedsensor, new batteries and cables ends. every time I make a change it runs fine for a day or two and I think Iv'e solved the problem only for it to return. any answers? Stormy

 

[Missouri Mule]

Did you change vehicle speed sensor or trans speed sensor? Trans temp sensor can knock it out overdrive don't know about lock-up.

Have you checked wiring and connectors for problems?

 

[PhillipFleming]

What all did they replace during the overhaul? ive had the best luck with mopar governer pressure senser & gov press transducer. the after market ones dont last. also if the line pressue was set to high it will do funny stuff. I speek from exp on that one man. whats the tps doen/ do you have acess to a scanner to see the tps voltage?

 

[RVPILOT]

Dont know yet but I think it might be a loose connection at the speedsensor or trans temp. time will tell. stormy

 

[royalfh]

I have had this problem occasionally, TPS was original culprit, i have opened it and cleaned the contacts and found that to work. Most recent time the problem drove me crasy it was the brake pedal switch. Usually you notice brake lights staying on or flashing the guy behind you to their annoyance, last time there was just enough play in the switch to make the trans jump out of overdrive when i hit a bump in the road, holding the brake pedal up with my foot did not stop the problem. It was only when the brake lights started to stay on that i replaced the switch and it cured the OD issue too. Switch is only $10. 00.



Nigel, 1996 2500 2wd. 400K ml.