Determining Weight Capacity Of Axles On Trailer For Replacement Springs

Question:

how can i tell the spring weight of my axels. I have 2 broken springs and want to go to heavier springs if i can do it

asked by: Craig H

Helpful Expert Reply:

There are a couple ways to determine the weight capacity of your trailer springs. First, there should be a sticker or tag on the axle that will tell you the axle capacity.

Second, you should have a tag on the trailer that says what the weight capacity is for the trailer. Axles are typically installed on a trailer with that capacity.

Third, you can measure the diameter of a round axle to determine the capacity. Here is a list of typical axle diameters and their weight capacity. I recommend using a digital caliper like part # PTW80157.

1,000-lb - 2,000-lb Axles: 1-1/2" - 1-3/4" diameter
3,500-lb Axles: 2-3/8" diameter. Some may measure 3-1/2 inches diameter but not often.
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.

The replacement springs will not increase the load capacity for the trailer. If you install heavier springs on the trailer it can result in a stiff, uncomfortable ride.

I have attached a helpful article that explains trailer suspension you can check out.