I just purchased a 1999 Itasca 32T class A from a private party. It has about 55000 miles.
Just made a 700 mile trip and while traveling, noticed a terrible vibration (like a bumping) when going up a hill and the speed drops to around 55 and the tranny downshifts to a lower gear and it revs to around 3000 rpm. But if I mash the gas and it goes to 4000 rpm, it screams but no vibration. Also, when I'm going 60 - 65 on a slight grade and giving it gas, the same thing but only slightly happens. When I let off the gas, it goes away.
This is my first motorhome of this size so any help identifying this problem would be greatly appreciated.