Tire issues

I own a 2003 Viking 2270 pop up. I am having unusual tire wear with radials that are only a couple of years old. Two tires have done exactly the same thing. They are Loadstar 175/80D13's 8ply load range D. They are mounted to a Dexter Torflex axle. The drivers side tire has a bulge that runs the circumference of the tire toward the outer wall. It happened on the tire that was there before I changed it. Both tires, including the spare were purchased at the same time from etrailer.com. I used to have Loadstar bias tires. They were on there for a good number of years. I seem to remember unusual wear on the outsides of the tread and thought that the radials would run smoother. I always keep them aired at the max pressure which is 65psi. The passenger side radial looks perfect with a nice, square tread. I have noticed that the drivers side is noticeably higher on that side of the trailer. I have not measured it yet, as we just got back from a 400 mile run. The tread is perfect on the bulged tires. I do know that the trailer was in some sort of rear end accident before we bought it, possibly the past owner backed into something. I am leaning towards a problem with the axle on the driver's side. Could it be the Torflex is messed up? Anyone else seen tires do that? Suggestions are greatly appreciated! Thanks!