Determining the Capacity of a Square Trailer Axle

Updated 06/11/2012 | Published 06/08/2012

Question:

i have about a 3 inch square tub axle with a spindle C dimension of 1.375 dia what is the rating of this axle the tire says 2540lbs it is 92 inch wide hub to hub

asked by: Norm L

Expert Reply:

Square axles can be tough to determine capacity. Often times the same spindle fits a range of axle capacities. The best way to determine the capacity is to get the inner and outer bearing numbers stamped into the metal of the bearings. Going by those numbers, wheel size, and bolt pattern, we can determine the probable axle capacity. I have included some links that might help.

There could also be a plate on the axle itself that lists the capacity. The most common place to find axle capacity is on a plate or sticker on the trailer frame on or near the tongue. Sometimes its location on the inboard side of the frame.

expert reply by: Michael H