What Over-Under Conversion Kit Will Work For My Trailer's Axle?

Updated 05/08/2026 | Published 05/01/2026

Products Featured in This Question

Dexter Trailer Springs Over-Under Conversion Kit

(829)

$95.84

Dexter Trailer Springs Over-Under Conversion Kit

(829)

$90.07

Question:

Hello, Id like to know which Dexter Over/Under kit I would need for my travel trailer. If this helps, the seriel number on the single axle housing is: 132509303007 Any help, info or guidnce greatlt appreciated. Best.......Daniel

asked by: Daniel Z

Expert Reply:

Hi Daniel,

I was unable to find the serial number online to find what its specifications are. Luckily, determining what over-under axle kit you need can be done just based on the measurements of the axle diameter and the leaf springs. It's important to note that over-under kits only work with trailers that have double eye leaf springs, not slipper springs.

The Dexter Trailer Springs Over-Under Conversion Kit part # K71-385-00, is for axles with a 3" diameter and double eye leaf springs only. The other Dexter Trailer Springs Over-Under Conversion Kit part # K71-384-00, is intended for use with axles that are 2 3/8" diameter with double eye leaf springs only. It will work with leaf springs that are up to 1 5/8" wide.

A 3" diameter axle is much more common than a 2 3/8" diameter, but you'll need to measure the diameter of your axle to determine which kit will work. If the axle diameter is not one of the two sizes it will not work for your trailer. If installed, the over-under kits are able to "lift" the axle 4.5" to 5" by raising the leaf springs over the axle. I've included a link about measuring trailer axles to guide you in measuring the diameter to determine what will work for you.

Where do you like to take your trailer camping at?

expert reply by: Claire H

Daniel Z.

5/4/2026

Thanks Claire, The outside diameter of my travel trailers axle is 3” I will order the Over/Under lift kit accordingly. We like to visit and camp in areas nearby to where we live near Flagstaff AZ. We also like spots in Utah, and also around the Ouray, Montrose, and Durango Colorado region, as well as camping on our parcel of land that faces east towards Humphreys Peak AZ where Elk are in abundance, and the dark night sky allow for ideal stargazing. Happy Camping and RV’ing Ya’ll Daniel

Claire H.

5/4/2026

@DanielZ Perfect! The K71-385-00 kit will be what you'll need and will get some extra clearance for your travels. I've never been to AZ or Utah yet but those are near the top of my list for places I want to visit for camping.

Keith

5/5/2026

So I installed the over/under lift kit on my 17’ trailer with Dexter axles. Raised my trailer about 4” which I needed to pass through our creek bed road here in West Virginia. The installation was very easy. The one thing that is recommended, and I highly agree with, is to weld the brackets in place after installation per the instructions. This is very important. Don’t just rely on the jack screws. There’s huge torque and impulse forces in that area when you hit potholes or curbs. This will definitely bend the jack screws and cause problems. All in all i highly recommend this if you need to increase the ground clearance of your trailer. I would not recommend it for other purposes. This installation raises the center of gravity height significantly. So only utilize this approach if you keep dragging the trailer backend or hitch area.

Claire H.

5/8/2026

@Keith Appreciate you sharing that—glad it worked out and got you the clearance you needed. Good call on welding the perches too, that’s definitely important. And yeah, the center of gravity is something people don’t always think about.

Thad F.

5/5/2026

Have 3 inch axles raised my trailer 4 inches . Weld the brackets to the axle. Was great for not having to worry about dragging my trailer. Hunt NM Az Co and Ut has been great. Have it on my 12 foot and my brother has it on his 16 ft. Works great. Absolutely recommend.

Claire H.

5/8/2026

@ThadF Thanks for sharing! It seems like everyone is saying the recommended welding for the brackets is a must, which is good for us to know for others who might be wanting the same kit. We appreciate your feedback!