2001 5.9 Ram automatic trans shifts up an down,tac goes up to 3 grand and back down,having problems climbing hills,please help,Thank You Rick the truck goes up a gear an then back down a gear when climbing a hill over revving the engine. Thanks Rick Truck stays in lower gear sometimes an won't go into higher gear in over drive or drive ?

 

Could you be a bit more clear in just what the issue is here?

 

Are you sure it's shifting, or maybe the overdrive is cycling on and off?

If it is falling down a gear and then back up you may have a failing pressure sender.

I just replaced my solenoid and sender with great results. From what I have read there are several problems and symptoms that stem from either or both failing.

 

Blown plenum and clogged Gov solenoid.