[Diamondpilot]

I agree with these guys. I am a trailer dealer, boat trailers, but still relevant. You have a miss aligned axle, bent axle, bent spindle, bad bearings, bad brake, bent hub, or some bent rims. The first thing I would do is what you have already done, check the bearings. You really need to take it to a tire shop and have all 5 tires spun balanced. You can then take it to a spring shop if the problem remains. When I say spring shop I am talking about a heavy equipment shop that works on things like school buses and dump trucks and have things check out.

Chris