I have a 2001 dodge Durango with 130k miles
When I was pulling a 5x8 uhaul trailer with 200 pounds in the trailer I had problems going up hill.
When the RPM were above 2500 it would try to shift down and the rpm jumped about to around 3500rpm. It would then shift up or back to 4 gear and back down to 2500rpm. This would continue until I press on the gas to force it to stay above 3500rpm. After the hill to continue to run fine as long as I stayed below 2500rpm. Using OD on or off didn't matter. I even tried 4wd on and off with no change. The fluid level is good. Pulling the trailor without a doubt makes the problem worst it seems.
I have read most of the other posts about replacing the TPS but not sure if it could be something else.
Using cruise control makes the problem worst. No engine warning light also.
Thanks for the help with this old girl. She has been good until this towing issue other than O2 sensor(lights engine warning light) problems if I get bad gas from time to time