What Is Needed to Determine the Correct Replacement Leaf Springs for a Boat Trailer

Updated 10/30/2025 | Published 02/01/2025

Products Featured in This Question

Equalizer for 2" Wide Slipper Springs - 12" Long - 7/8" Center Hole

(165)

$69.58

4-Leaf Double-Eye Spring for 3,500-lb Trailer Axles - 27" Long

(2045)

$62.24

Question:

I just bought this boat trailer and went to measure for new springs and I think they have installed wrong springs previously, are they meant to be eye to eye. Also when i measure center to center of bolts it measures exactly 700mm but all eye to eye leaf springs for sale are 711-715 centers? Any help would be appreciated, thanks

asked by: Kyle

Old Leaf Springs
(click to enlarge)

Expert Reply:

Hey Kyle, first of all congrats on the trailer! It might look wrong but don't worry it's not. Over time, leaf springs will flatten and elongate causing them to measure a bit longer than when originally installed. Since we are talking about less than an inch here of difference, I'd say with good authority that that's what happened.

To double check that you have the right measurement, you're going to need to let your trailer's axles hang free and measure the eye to eye, the width, and the height. I've attached an FAQ for you to check out to help.

It's very possible that something like the 4-Leaf Double-Eye Spring for 3,500-lb Trailer Axle # e97SR will work fine, but I still recommend measuring again to be sure.

If there is something else I can help you with, please feel free to let me know in the comments I'd be happy to help!

expert reply by: Bryce D

Gwendolyn Y.

10/30/2025

Hey Kyle, how did your re-measurement go with the trailer’s leaf springs after letting the axles hang free? Knowing what you found could help others trying to match the right spring length for their setup.