How to Determine Axle Rating on Unmarked Homemade Trailer

Question:

If its a home built trailer and their is no Vin how do I find the weight rating of a trailer axle?

asked by: Tommygun

Expert Reply:

Without any identification on the trailer you can either check the axle diameter or the bearings and hope there is a common bearing combination. The typical axle capacity based on diameter is as follows:

Typical Axle Diameters Based on Axle Capacity:
- 1,000-lb - 2,000-lb Axles: 1-1/2 inch diameter - 1-3/4 inch diameter - 2-3/8 inch diameter
- 3,500-lb Axles: 2-3/8 inch diameter - 3 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

To be clear, this is the typical correlation, there is no guarantee it is what you have. I have also attached an article below with the common bearing combinations. Matching these up is a good indication of your capacity. For example, a standard 3,500 lb axle use a # L68149 inner and # L44649 outer bearing.

Please keep in mind, since someone else built this trailer there may be mismatched parts that aren't rated as high as the axle. You will be limited by the weakest component.