How To Determine Weight Capacity of Double Eye Leaf Springs on Trailer

Updated 07/03/2012 | Published 06/29/2012

Question:

I have a pair of double eyelet leaf springs that measure 22 1/2inch center to cente,has a 5 1/2inch arc,5 leafs,1 3/4inch wide ,5/16 thick. what would weight rating for each.

asked by: Pat M

Expert Reply:

The best way to determine the weight capacity of your leaf springs would be to check the weight rating of the axle on your trailer. The trailer will have a plate or sticker on it that will list the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that will list the weight capacity.

You can also tell the weight capacity of the axle by measuring the diameter of the axle. A 2,000-lb axle will have an axle diameter of 1-3/4 inch. A 3,500-lb. axle will have a axle diameter of 2-3/8 inches and a 6,000-lb. to 7,200-lb. axle will have an axle diameter of 3 inches.

Since the axle will have two leaf springs, one on each side, the weight rating of the leaf springs will be 1/2 of the weight capacity of the axle. For example, a 3,500-lb axle will use two leaf springs rated at 1,750 lbs each.

I am including a link to a FAQ page on trailer suspensions and it will list the axle diameters for different axle weight capacities.

Also, I am including a link to a FAQ page on leaf springs. It will have a chart that will show the sizes and capacities of the leaf springs. The number of leafs and thickness of each leaf is not a direct indication of the spring capacity.

The 4-Leaf Double-Eye Spring, part # e54SR, you have referenced is a spring designed to be used on a 3,500-lb axle.

expert reply by: Jeff D