Recommended Hanger Spacing For 4-Leaf Springs on Tandem Axle Trailer

Updated 02/03/2012 | Published 01/31/2012

Products Featured in This Question

5-Leaf Double-Eye Spring for 6,000-lb Trailer Axles - 25-1/4" Long

(2045)

$73.50

Question:

I have new hangers and PR4 springs with new equilizer. what is the proper spacing for the hangers. From front to center to back hanger. Also should the axle with brakes be the front axle or back axle? Thanks for your help. hanger spacing for tandem axle 3 in. axles

asked by: David A

Expert Reply:

You mention that you have a tandem axle with 3 inch axles. A 3 inch axle has a weight capacity rating of 6,000 lbs to 7,200 lbs. The leaf springs for that axle would be the part # e34SR. These springs have a weight capacity of 3,000 lbs and are designed for 6,000-lb axles.

The # SP-218274 (PR4) springs you have mentioned show a weight capacity of 2,500 lbs. So two of the # SP-218275 springs are designed for 5,000-lb axles. I would recommend to check the weight capacity of your axles to make sure you will be using the correct springs for your trailer.

The proper spacing for either of these spring's hangers on a tandem trailer with a 3-inch axle is from the center of the front hanger to the center of the center hanger will be 29-1/2 inches. From the center of the center hanger to the center of the rear hanger is also 29-1/2 inches. The distance between the center of both axles should be 33-1/2 inches. These measurements are without any weight on the trailer. I strongly recommend mocking up the trailer suspension before welding any of the tabs on. I am including a picture that will show these dimensions to start with.

On a tandem axle trailer I would recommend brakes on both axles. You will also want to check the laws of your state, because some states require tandem trailers to have brakes on both axles.

If you are only doing brakes on one axle it would really depend on the type of trailer you have and what you will be hauling. There does not seem to be a definitive answer for brakes on front axle or rear axle.

I am including a link to a FAQ page on double-eye trailer suspensions.

expert reply by: Jeff D