If you have one shoulder of a trailer tire showing more wear than the other, as seen here, you probably have camber wear. [From bridgestonetire.com: Camber: This is the inward or outward angle of the tire when viewed from the front of the vehicle.]
Unlike the front end of your car or truck, few RV trailers have alignment that can be adjusted with hand tools. BUT the first thing you need to do is confirm you are out of alignment.
Assuming that the axles are still firmly bolted to the trailer frame and there are no obvious bent or damaged spring shackles, you might need the help of a professional RV Trailer Alignment shop as seen in THIS video.
But you might want to first confirm that you even need to have the axle replaced or “bent”.
Measure the camber and toe-in
You can measure your camber and the toe-in. [From bridgestonetire.com: Toe: Distinct from camber alignment, toe alignment is the extent to which your tires turn inward or outward when viewed from above.] Here’s a low cost Camber Tool.
How to measure the toe alignment at home. This video is not of an RV trailer but it does a good job of showing how to be sure the axle is square. While this is on a car, you should be able to see that we are looking at having the front and rear of the two tires on the same axle being the same distance apart.
Here is a video of another trailer having the axles measured.
I tried contacting Lippert to learn the alignment specs for Camber and Toe. They would not give me the information without providing the VIN and other info on the trailer. I don’t understand this, as logically Camber should be near 0° and typical toe-in specs vary from 1/32″ to 1/8″, with closer to 1/32″ being better for tire wear.
I did find these Reference Documents for Lippert Axles.
Have a tire question? Ask Roger on his new RV Tires Forum here. It’s hosted by RVtravel.com and moderated by Roger. He’ll be happy to help you.