Can I Use Heavier Rated Leaf Springs on Trailer Without Causing Damage

Updated 04/21/2025 | Published 05/02/2020

Question:

I have tandem axles rated at 7000 lbs each and of course my RV is rated at 15,500 GVW, obviously under rated from the manufacturer. My leaf springs need replacing. Is it advised to go with springs rated for GVW or only for axle rating. If I put springs rated heavier than axles, is there a chance for damaging axles?

asked by: Gary B

Expert Reply:

You can use leaf springs that are rated higher than the axle without any issues as long as they measure the correct measurement for your trailer. For example the 6-leaf double eye spring for 7,000 lb axles part # e64SR measures 24-7/8" eye to eye. The only thing you may notice is that the ride may be a bit stiffer with the heavier rated springs.

Please keep in mind upgrading to a 8,000 lb spring may require you to switch over to slipper springs instead of double eye springs. Which is possible by switching the hangers to slipper spring hangers and hardware but does require some work. The slipper springs are designed for heavier duty trailers.

expert reply by: Heather A

Boat S.

4/6/2025

Hi Heather my name is Ron Cancilla I had a fishing tournament yesterday and at the launch I noticed that my tandiom trailer had a broken leaf spring. I was 2.5 hours away from home and I needed to fix it. I found a 5 leaf leaf spring but the existing one was 3 leaf. I had to use it to get my boat of the water. the new one was the same size and bolted up just fine . I doesn't look any different with the boat on. I want to change the other 3 springs so they are all the same . will this matter to the frame , I realize it will ride a little stiffer. the gross weight of the trailer is 4500 pounds. thanks for your help

Jameson C.

4/21/2025

@BoatS What is the weight rating on the new spring? That's more important than the number of leaves when considering what the ride quality would be. Running a stiffer spring though doesn't negatively affect the frame though so if the spring is stiffer it's not going to be a problem.

Pete T.

4/16/2025

Hi Heather, I have a 2018 Grand Design Solitude 375RES, double 7000lb axles. My 3500 lb double eye leaf springs are worn out. My unloaded weight on the drivers side is 500 lbs heavier than the passengers side due to fridge, stove, pantry etc. I suffered a broken drivers side, front spring a couple of days ago. Dry weight is listed as 14,500 lb but it is actually 15,000 lb. My loaded weight is 16,500 or maybe a bit more. My current double eye springs are 25" unloaded. I am thinking i want to to go 4000 lb springs, if I stay with double eye. I want to know what your opinion would be on going to a slipper vs double eye. If i did go slipper, would I need a 4000 lb slipper or 3500 slipper? Can you send me part numbers and cost of what I would need for both double eye and slipper setups. Thanks

Jameson C.

4/21/2025

@PeteT If the weight of your trailer is 16,500 lb then you'd need springs rated for basically at least 8,250 lbs per axle. I am assuming the spring rating you mentioned was per spring and not axle as 4k per axle wouldn't even be close.