How To Determine the Weight Capacity For a Trailer Axle

Expert Reply:

The trailer will have a plate or sticker on it that will list the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that will list the weight capacity.

You can also tell the weight capacity of the axle by measuring the diameter of the axle. Here is a list that will show the axle weight capacity based on the axle diameter:

Typical Axle Diameters Based on Axle Capacity
- 1,000-lb - 2,000-lb Axles: 1-1/2 inch - 1-3/4 inch diameter
- 3,500-lb Axles: 2-3/8 inch diameter
- 6,000-lb - 7,200-lb Axles: 3 inch diameter
- 8,000-lb Axles: 3-1/2 inch diameter
- 9,000-lb Axles: 4 inch diameter
- 10,000-lb Or more axles: 5 inch diameter

Those suggestions would be the easiest way to find the weight capacity on your trailer axle. If you cannot determine the weight capacity using the above suggestions the next step would be to measure bolt pattern on the hub, size of brakes, and bearing part numbers. With this information we could narrow it down to what size axle you have on your trailer.

I am sending a link to a FAQ page that has information on trailer suspensions.

expert reply by: Jeff D