Bought a Four Winds Chateau Sport a month ago. Coming home we had a bad vibration that turned out to be a bad tire. RV had new tires on the front, 2011 tires on the back. Replaced all four tires on...
Lots of causes of vibrations. You need to check them one at a time:
1. Is the vibration more noticeable in the steering wheel or floor (front or rear)?
2. Even before checking tires for balance, you need to check them for RUN-0UT. If over .035" fix it-- even a perfectly balances egg-- well, it rolls like an egg.
3. Then balance the tires. On front, best to balance on the rig.
4. After tires have been eliminated as the cause, check U joints and drive shaft alignment.