How Do I Choose the Correct Length Leaf Springs for My Boat Trailer?
Updated 11/06/2026 | Published 11/01/2026
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Question:
I need help deciding what size springs to get for my boat trailer. I measure 25-1/2 inches C to C from the front bolt to the top rear bolt, but 26 inches from the front bolt to the bottom rear bolt at the spring hole. Which measurement is the correct size? Single axle, 3500 lb. trailer
asked by: Jerry P
Expert Reply:
Hey Jerry, thanks for reaching out! For your single-axle, 3,500-lb boat trailer, I recommend the 25-1/4" Double-Eye Leaf Spring # TX58RJ. This is one of the most common spring lengths for a 3,500-lb axle and looks like a good match for your setup.
Leaf springs can flatten and stretch as they wear, sometimes gaining up to an inch in length, so your existing springs measuring 25-1/2" to 26" may have originally been 25-1/4". The correct measurement is from the center of the front spring eye to the center of the rear spring eye, rather than the mounting bolts or spring hanger holes. I do recommend replacing both springs together to keep your suspension balanced.
Also, since you are replacing your springs, you will need new U-bolts # APUBR-1 as well.
Are your current springs noticeably flattened out, or do they still have a good arch to them?
(click to enlarge)
Product Page this Question was Asked From
Terran Industries 4-Leaf Double Eye Spring for 3,500-lb Trailer Axles - 25-1/4" Long
- Trailer Leaf Springs
- Double Eye Springs
- 3500 lbs
- 4 Leaf
- 25-1/4 Inch Long
- Standard Grade
- Terran Industries
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Jerry P.
11/2/2026
Hello Jesse, Thanks for the quick reply and information. Yes, I believe my springs have flattened out. Looking at the photo in your reply, my springs do not have as much of an arc as the one in the photo. Thanks again for your help!