I have 2009 Jayco 30.5 BHS which came with Goodyear Marathons and I had several issues with those tires. I upgraded to load range E tires from Carlisle that are the same size as original tires, 225/75r15. I am very happy with the new tires. They ride a lot better and the trailer is not so bouncy when it hits bumps. This was a better option for me because I did not have to buy new wheels since the new tires were there same size just a higher load rating.
If you do decide to go this route, make sure your current wheels are rated to handle load range E tires. The wheels should have the max PSI rating stamped on them and it needs to be 2830. The wheels that came on my Jayco were rated at 2830 so maybe yours are also.
Here is link to tires I bought. Discount tire sells them.