Thank you all for the info. It gives me more things to look at. The tires are regular Michelin tires because every tire place I talked to said that regular ones would be fine for occasional towing. I replaced the old tires with new ones and still have that problem. I do not know about the camper tires. I have not replaced those. We do have stabilization bars on it. It seems to occurs when we hit about 55-60mph. It does ride low in the back, however. We have tried fixing that when hooking it up upon the recommendation of the camper dealership with no change. I have talk to two different camper places and they dismiss the problem and don't seem to think it is worth looking at. If it is a weight or size issue I am open to buying something new but wanted more opinions before I spend the money. We are carrying 4 adults and 3 large dogs in the vehicle. A lot of this stuff I can have looked at now that I know more questions to ask.