How to Estimate Boat Trailer Axle Weight Rating Based on Axle Dimensions and Hub Bearings

Question:

Trying to determine the weight of the axle that has three leaf springs on each one and the axle is 2 by 2 square

asked by: Ruben C

Expert Reply:

Axle weight capacity can be roughly estimated based on the axle tube dimensions. A 2 x 2-inch square axle like yours is likely to be rated in the range of 1800- to 2000-lbs. An example of a similar axle is part # CE33201GA-HUB.

Below is a recap of common ROUND axle ratings and diameters; square axles can vary more in their ratings.

1,000-lb - 2,000-lb Axles: 1-1/2" - 1-3/4" diameter
3,500-lb Axles: 2-3/8" diameter; Can have a 3-1/2" diameter, but rarely
6,000-lb - 7,200-lb Axles: 3" diameter
8,000-lb Axles: 3-1/2" diameter
9,000-lb Axles: 4" diameter
10,000-lb Or more axles: 5" diameter

Another way to figure it out is to take note of the bearings used inside your hubs. The bearing set used in your trailer hubs can get you close to the axle rating too. You can refer to the linked article concerning the most common bearings used based on axle capacity.

If for example your hubs use either bearing # L44643 or # L44649 (or a combination of these two) then it is likely the axle has a 2K rating.