How to Determine Correct Slipper Spring Replacement for 1,500 lb Axle

Question:

Im replacing the leaf springs on my boat trailer and Im having trouble finding ones that match the size of my old ones. They are slipper-type springs for a trailer with a GVW of 3000 lbs. I measured the distance where they are mounted from bolt-center to bolt center and its 24.5. The actual length of the existing springs from center of spring eye to end of spring is about 26. The springs also have a distance from bottom of curve to trailer of about 6. Ive attached pictures showing all these dimensions. I cant find anything on your site that matches these dimensions can recommend a ion? Also, I would like two other things to my trailer: shock absorbers and new hardware to connect the axel to the springs with two U-bolts per wheel instead of just one. My axle is 1.5inch wide. Ive attached more pictures to give you a look at that as well. Can you make a recommendation for those? Thanks!

asked by: Todd

Helpful Expert Reply:

What happens to slipper springs is that over time they elongate and flatten out, particularly if your springs are considerably older. The most important measurement you mentioned was the 26 inches from the center of the spring eye to the end of the spring. Based on that the closest slipper spring we have that could work is the 3-Leaf Slipper Spring w/ Radius End for 1,500-lb Trailer Axles - 24-5/8" Long # SP-178275, which would work if you had a tandem-axle trailer. There are no slipper springs that are short enough with the dimensions you gave that will work for a single, 3,000 lb or above axle.

You will need the Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long # 166079 for this slipper spring, and the u-bolt kit you need for your 1-1/2 inch square axle is the CE Smith U-Bolt Kit for Mounting 1-1/2" Square Trailer Axles # CE23102, which gives you two u-bolts per side.

In regards to shock absorbers the only option we carry which will work for you is the Timbren Trailer Suspension Enhancement System Light-Duty Trailers 1,000 lbs # TTRA1702 because all the other shocks are designed for trailers with heavier-duty axles. Still, the Timbrens are a good option that will install between the axle and your frame to give it the support it needs, as you can see by the linked instructions, which I recommend taking a look at.

I have also added links to video reviews for you and a help article on slipper spring suspension which has a lot of really useful information.