My fifth wheel has approximately 10,000 miles on it. I’ve noticed that the tires on the rear axle are wearing unevenly on the inside. What causes this? —Gary Melton
Uneven tread wear has many causes. They are:
• Too much weight over the axle: Too much weight over the axle will cause it to be bowed down in the middle due to the excess weight, and that will change the tire camber. Your axles have a maximum weight rating on a sticker on the axle. Refer to that sticker and have your trailer weighed at a CAT scale near you to determine if your axles are overloaded.
• A broken axle: Hitting a curb, large road debris, or a large pothole can cause an axle spindle to bend, which will result in abnormal tire wear. Axles also have a slight bend in them at the center. If an axle has lost it’s bend, it is also considered broken. A broken axle must be replaced.
• Axle being out of alignment: If your axles weren’t installed square with the chassis or parallel to each other, the tires are scrubbing as you tow the trailer down the highway. Misalignment can also be caused by worn bushings in the suspension. You can determine if it is an alignment issue by running your hand back and forth over the worn area. If the tread feels smooth in one direction and sharp in the other, you most likely have an alignment problem. A commercial alignment shop can correct an alignment problem for you.
• Tires not being inflated properly: If you have a balding center area on one or more tires, the tires are overinflated. Balding outer edges mean they are underinflated. For proper inflation, refer to the sidewall of the tire for the max PSI rating and inflate them to that number when the tires are cold.
Mark Gorrie has been an avid RVer since 2003 and owns RVForce LLC, a full-service mobile and shop-based RV repair facility based in Winter Haven, Florida. RVForce has a full team of certified technicians on staff to answer your RV questions. Email them to firstname.lastname@example.org .