Can A 3 Leaf Spring Be Replaced With A 4 Leaf Spring?

Updated 10/08/2026 | Published 08/23/2024

Question:

Concerning my 2018 Cruiser RV Funfinder extreme lite 26RB. Can I randomly update from a 3 leaf to a 4 leaf spring as long as the dimensions are identical? Is there any safety issue to oversizing?

asked by: John Z

Expert Reply:

Hello John. When replacing leaf springs, the important thing is to make sure the eye-to-eye length of the spring stays the same. We also want to make sure the spring has an appropriate weight rating for your axle. As long as these specs match, it is fine to go from a 3 leaf to a 4 leaf.

To add stability, some people will upgrade to higher rated springs, which can be done, but we do not want to overshoot the weight rating by too much. If the spring is rated too high, it will not flex and it will cause your ride to be very rough.

Let me know the eye-to-eye length of your springs, as well as the weight capacity of your axle and I am happy to look into it and see if we have any springs for you.

expert reply by: Jesse M

John

8/23/2024

I have a 3500 lb axle rating on both of the tandem axles. I cannot tell if the eye-to-eye length of the spring is 25-1/8 or 25-1/4. Is it crucial to have this exactly or will either do? I see your website offers both.

Jesse M.

8/26/2024

@John In this case either will do. A 1/8" difference is not going to be a problem at all. Here is what I recommend: - 4-Leaf Double-Eye Spring for 3,500-lb Trailer Axles - 25-1/8" Long - 3500 lbs # e54SR

Scott M.

9/14/2025

I have a 5 x 8 utility trailer with a broken leaf spring

Jesse M.

9/15/2025

@ScottM Hey Scott. Did you get a chance to jack up one side of the trailer and measure the unloaded spring? Let me know that measurement as well as your axle weight capacity and I am happy to look into it and see if we have a replacement spring for you.

Thomas B.

8/20/2026

I got 33 inch double axle 3500 on keystone Springdale looks like springs are flat eye to eye 26 the I install cr3000 with wet pin shackles very close to equalizer the springs on it are three leaf I was wanting to know if I went with a 25 1/4 four leaf. 1.75

Jesse M.

8/20/2026

@ThomasB Yes, a 25-1/4" spring is likely the correct size for you. Leaf springs can flex up to 1" so if your springs are flattened out and measuring 26", its likely they were originally 25-1/4" long. That is a very common spring size for a 3,500 lb axle. Here is what I recommend for replacing them: - 3-Leaf Double-Eye Spring for 3,500-lb Trailer Axles - 25-1/4" Long # EM46RB

Doug

10/8/2026

Have 7k 12’ flat bed. Axels are hitting and damaged frame. Removed one 4 leaf. Arch is good. O tandem axel. 3500 each. My jeep weighs 5k trailer weighs 1k