joytitra, just read through your thread again. I still say you need new trailer tires but another good point was raised. What truck tire do you have? I purchased a new tundra in 2008 and pulled my hybrid with it. When I got my Airstream I had to reset the hitch and it looked good. I had many miles towing with it until one day I felt a tiny bit of sway coming down a slight hill. I had some kind of P rated tire and read that weak sidewalls will create sway. I was due for new tires and moved up to LT tires and it made a lot of difference. So, trailer AND truck tires might be issue.