I have a '95 2500 with 192,000 miles and the truck is stock. I pull a 6,000 lb camper and have had what I think is the torque converter lock - unlock problem on and off for a couple of years now. It will usually start an hour or so into pulling the camper, RPMs increase then decrease about 250 RPM at highway speeds. It happens in 3rd and in OD and I believe it has even happened in 2nd a few times. It will sometimes continue for a while after I unhook the camper but after a while of driving without the camper the transmission seems to return to normal. I have cleaned the TPR terminals, unhooked the battery overnight to clear out the memory in the PCM, and changed fluid and filter a few times. This seems to calm things down a bit but the problem usually reoccurs shortly. I found the instructions for checking voltage on the TPS but it seems this only controls the 3-4 and 4-3 shifts. Any suggestions from the pros?

 

Electrical noise from the alternator.
Clean ALL grounds, put aluminum foil around the cable behind the alternator, and get a DTT noise filter.

 

95 doesn't have all the electic controls on tranny. Doubt is noise. Consider a heavy duty VB. That will raise lock up pressure and probablly prolong life of converter. Are you using ATF + 4 fluid?

 

I am using ATF + 4. Would a torque converter lockup switch work as a last resort when pulling? I am hoping not to have to go into the transmission to work on the TC or VB.

 

go to radio shack and get a clamp on rf filter. put it on the wire comin out of the alt....this will work..believe t or not....its 5 bucks....if its elec noise it will fix it.i was ready to sell my truck til i did this ..its worth it.