Troubleshooting Inner Trailer Tire Wear

Question:

I run 4.80 X 12 Load Range C tires on my boat trailer. I was running them at the required 90 PSI but found the inner most treads were wearing much faster than the outer treads so Ive lowered the pressure to 60 PSI. After running them at 55 mph for 2 hrs. the tires are not warm at all. I know you say they should be run at max. PSI but could you explain the excessive inner tread wear? Thanks for your help

asked by: Bob L

Expert Reply:

Excessive inner wear on both tires typically means that the trailer is being overloaded. When your trailer is overloaded for an extended amount of time the axle could be bent which means that it is not holding your load appropriately resulting in the excessive wear on the inside of your tires.

Another possibility is that the axle is flipped. Generally, an axle is flipped to gain more height, however, the natural bow that is in the trailer that helps support the load will be facing the wrong way and the tires will naturally tilt in at the top resulting in inner tire wear.

Camber is defined by the measurement of degree difference between the wheel vertical alignment perpendicular to the surface. Your tires will have a negative camber if your trailer is overloaded which will result in excessive wear on the inner sides of your tires. Toe in is when your tires face slightly inward which is typically on an automobile and not a trailer.

Of course having your trailer checked is a good idea to verify there are no broken parts such as the axle or springs.

expert reply by: Jameson C