Q: I bought my 1995 Thor fifth-wheel used and it had two or three tires blow out in just the first few hundred miles, so I took it back to the dealer and they sent me to a place that did axle work on trailers. The shop put a jack under the center of the axles, raised the center, and got the right arch in them so the tires were running true. Then he welded a piece of angle iron from one side of the axle to the other on each axle. It must have worked because I have never had any blowouts after that.
Mr. Ladd, Harlingen, Texas
A: You’ve discovered a trailer tire failure cause that’s probably a lot more common than most realize. Misaligned trailer axles are responsible for many prematurely worn tires experienced by RVers. You were lucky to find a shop that was familiar with the problem.
It’s possible excess weight on the trailer axles, caused by too much trailer weight or too small an axle, caused the center of the axles to bend down a bit. The leverage effect of the tires at the ends of the axles plus the trailer weight inboard from the tires causes the center of the axle to bow down. This causes the tire camber to be thrown out of alignment, which tilts the tires in at the top, and in turn causes faster tire tread edge wear due to uneven tread contact with the road. Bending the axle center up realigns the camber. Other readers with suspicious trailer tire wear problems might want to consider finding a local shop that knows about trailer axle alignment and have their rigs checked out, too.
– Jeff Johnson
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