I have an '02 Ram 1500 w/ the 5.9L, 4wd, auto tranny. The truck has 82000 miles.

I have never had any sort of transmission problem with the truck. I had full tranny service (fluid, etc) about 6,000 miles ago.

Last week I started to notice, while driving down the highway (65-70mph), that the RPMs would randomly jump from about 1750 to 2000-2200. That lasts for a second or less, then it returns to normal. I am driving on flat ground and not trying to accelerate or decelerate.

The tranny fluid is fine--I checked that. The problem seems to be getting worse. I can feel it when it happens, and my husband also felt it before I had mentioned it to him. It seems to do it more frequently and slightly more drasticly than initially. Like I said, the transmission has never slipped or anything before. I thought maybe it was the overdrive switch, but it still did it when I turned the overdrive off. I have also noticed it does it at lower speeds/RPMs too.

I was thinking maybe less an actual transmission problem than a shifting controller problem. Any thoughts? Thank you.