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When the rear end squats under a heavy load, steering and braking can quickly feel uncertain. This Timbren Suspension Enhancement System adds up to 7,000 lbs of rear axle support using hollow rubber springs that sit above the axle. The springs get more rigid as weight increases, keeping your vehicle level and stable when hauling or towing. With the extra support, handling feels more controlled and the front tires maintain proper traction for safer driving.

Big loads don’t have to mean a rough ride. The Aeon hollow rubber springs absorb most of the road shock so bumps and potholes don’t transfer through the chassis. The design allows normal suspension travel under light loads for a comfortable ride, then stiffens progressively as weight is added. That means you get the cushion you need when empty and firm control when loaded without bottoming out on rough roads.



Uneven loads or sharp turns can push one side of your truck harder than the other. Each Timbren spring works independently to support its side of the vehicle, reducing body roll in quick maneuvers or on off-center loads. When a trailer starts to sway or wind gusts hit, this independent action helps keep both vehicle and trailer aligned so handling stays composed and predictable.


Getting more suspension support doesn’t have to be complicated. This kit includes custom-fit brackets and hardware that bolt directly onto the frame rails with no drilling required. Once mounted, there are no air hoses, compressors, or adjustments to worry about—just reliable rear-end support every time you load up or hitch a trailer.
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hello everybody, this is Jeff at etrailer.com. Today we're gonna take a look at this Timbren severe service rear Suspension Enhancement System. Now this is a custom fit part. It is designed to fit the 2004 to 2008 Ford F-150 trucks and the 2004 to 2008 Lincoln and Mark LT vehicles. Now in a custom fit part like this, I do like to recommend for you to go to our website, use the fit guide, put in your year model vehicle, and it'll show if this a work through application. Now this kit here will improve the suspension, the handling, and the safety of your vehicle.
This is a severe service kit and these are recommended when you're using a top heavy load, like a slide in camper, a salt spreader on your vehicle. Any application that requires maximum stability, meaning reducing the roll and sway calls for a severe service upgrade. Now, most rubber springs used on the trucks are double convoluted, providing a perfect blend of capacity and ride quality. But the rubber springs used on the severe surface are a single convoluted Aeon spring. The single convoluted springs are shorter and wider.
You can see if I move these two pieces, here's your spring itself. They are shorter and wider. They're designed to resist weight more aggressively, and the result is reduced ride quality exchange for more stability. They do work independently side to side. They'll help compensate for any off center loads, and they do reduce body roll when you're swerving and turning corners.
They will act as shock absorbers taking the brunt of any bumps and rough roads, which will help extend the life of your vehicle suspension. Now this part will include everything laid out here on the table. It'll include the two Aeon rubber springs, the two spacers, and then the vehicle specific brackets and the hardware for a simple installation. Comes with a nice set of instructions that'll describe how this installs and goes together, and it installs directly onto the frame and replaces the bump stop. No drilling is required.
A few specs on this kit. The capacity is 7,000 pounds. Now, even though you're increasing the spring rate by adding this upgrade, this does not increase the gross vehicle weight rating of your vehicle. So you still wanna make sure not to exceed the manufacturer's recommended weight limit. And this kit is designed to work with a suspension system that is in good working order. But that should do it for the review on this Timbren severe service rear Suspension Enhancement System.
Ratings & Reviews

Heather A.
5/26/2026
Wow, that is exactly what we love to hear about these springs! That is a serious camper. Any plans with it this summer?

Tom E.
8/9/2026
Still working great! No issues. Other than being dirty, they look and perform like new.


James
7/27/2026
So far they have been fine. They are part of my suspension upgrades, along with stable loads and sway bar. I wasnt worried about harder ride when camper off, I wanted best suspension when camper was on. I would definitely recommend them.

Charles
2/8/2026
Excellent product. Does exactly what they were designed to do. I removed the sever duty extension. Now the ride is soft when unloaded. But yet smooth when towing or loaded heavy.



Scott
5/9/2026
They work great and are holding up well after a year in service on my 2011 F350 SRW hauling my Lance 855 truck camper.

Loren
3/6/2026
No changes, zero issues or regrets!

Bryan L.
12/11/2017
The air springs have performed flawlessly ,very pleased with the product and performance ! As a matter fact I was recommending this product to a friend the other day.
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Darin
7/5/2022
After a year the bushings are holding up great. They really help the stability of the truck when pulling the camper