How to Determine Required Trailer Axle Weight Capacity and Dimensions

Question:

I am currently building a 5.5foot 66 wide trailer by 12foot long. I am having trouble trying to figure out how wide of a axle I am going to need/want for this set up.

asked by: Roger

Expert Reply:

Axle dimensions are fairly standardized. Those we sell are offered in 4 lengths, 57-1/2-inch, 60-inch, 72-inch and 89-inch. We also have axles-less trailer suspensions from Timbren that bolt on to the trailer frame and eliminate the leaf spring suspension completely which can provide excellent ground clearance when that is an important factor.

You can see all of our axles on the linked page. For a 66-inch wide trailer you will probably want to use a 72-inch beam axle like # 20545I-EZ-72-10 or one of the Timbren kits such as # A35RS545.

You need to take note of the spacing of the leaf spring seats too. These seats are placed on the axle beam at varying distances depending on the axle size. An 89-inch beam axle typically has spring centers placed at 74-inches but it is possible to weld on new spring seats like # TRSS175 in different positions.

The most important consideration for selecting an axle is weight capacity. The axle(s) on the trailer must be rated to carry the combined total weight of the trailer itself plus the intended cargo.

expert reply by: Adam R