Measuring Axle Diameter to Determine the Capacity

Updated 05/15/2017 | Published 05/13/2017

Question:

I just read your how to determine what the weight capacity is for axles on my trailer. my question is in regard to measuring the diameter of the axle where are you measuring? Form the end of the spindle or?..where? thanks.

asked by: Travis

Helpful Expert Reply:

When measuring an axle to determine the weight capacity you'll want to measure along the actual axle tube. Anywhere between the spring seats will work fine.

I also recommend measuring with a digital caliper like # PTW80157 to get an accurate measurement. A digital caliper is a good tool to have when measuring for replacement bearings and other parts as well.

Once you have the axle's diameter the typical capacity based on measurements are:

- 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