How to Determine the Weight Capacity of a Triple Axle Trailer

Updated 07/16/2018 | Published 07/13/2018

Question:

Hi, I have a tri axel trailer, each axel is 3 inch diameter, rims are 16 inch with 6 lugs and tires are Goodyear st205/75r15. Someone wants me to build a tiny house on this, can you tell me how I determine the weight rating? The vehicle permit has a weight rating of 4800KG 10,500 lbs but this seems low to me for a tri-axel. Any help you can offer would be great. Thank you,

asked by: James C

Expert Reply:

Typically a 3" axle diameter would indicate that the weight capacity of the axle is 6K - 7.2K but that is not always in case. In some (rare) instances it could be a 3.5K axle which would make sense for your max capacity of 10.5K.

If you think that your weight rating is under what it should be then you will need to look at all of your components to determine which one has the lowest rating. The component with the lowest rating will, naturally, be your limiting factor. This includes the axles, tire/wheels, the trailer frame, and even the suspension parts.

I cannot recommend that you put more weight on the trailer than what the manufacturer says but you can do some checking on your own to verify that everything is rated properly for your application.

expert reply by: Jon G