How to Estimate Axle Weight Capacity Based on Axle Diameter

Question:

I built this trailer out of a travel trailer frame with no identification. The axle tubes are 2.75 OD and the wheels are 4 lug. It has brakes on all 4 wheels that I believe are10X2. I have installed 235x75R 15 10 ply tires. How can I determine the load weight of this trailer?

asked by: Cliff L

Expert Reply:

Since your trailer was built from unidentified existing components the only parts of it that will potentially have a weight rating are the axles themselves. Often axles will have their own sticker or plate with weight specs and sometimes part numbers.

Typically axles have the following weight capacities:

1-1/2-inch to 1-3/4-inch diameter = 1000-lbs to 2000-lbs
2-3/8-inch diameter = 3500-lbs
3-inch diameter = 6000-lbs to 7000-lbs
3-1/2-inch diameter = 8000-lbs

Keep in mind that a trailer's overall weight capacity will be that of its lowest-rated component. This could be the tires or wheels, the hubs, the axles or suspension or the trailer frame itself.

expert reply by: Adam R