1. Vehicle Suspension
  2. Timbren
  3. Jounce-Style Springs
  4. Rear Axle Suspension Enhancement
  5. Extra Heavy Duty
Timbren Rear Suspension Enhancement System

Timbren Rear Suspension Enhancement System

Item # TGMRTT15S
lowest price pledge
Our Price: $225.40
You Save: $39.78
Vehicle Suspension

Will this fit?

To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.

This item qualifies for Free Shipping
Shipping Weight: 6 lbs
In Stock
zoom in icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

7,000-lb Capacity. These hollow rubber springs sit above the rear axle to help stabilize and level your vehicle. They also provide a more comfortable ride by absorbing road shock and improving roll stability. Easy to install and use. Lowest Prices for the best vehicle suspension from Timbren. Timbren Rear Suspension Enhancement System part number TGMRTT15S can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (2194)
  • Q & A (11)
  • Photos
  • Why etrailer?

Timbren Vehicle Suspension - TGMRTT15S

  • Timbren
  • Jounce-Style Springs
  • Rear Axle Suspension Enhancement
  • Extra Heavy Duty

7,000-lb Capacity. These hollow rubber springs sit above the rear axle to help stabilize and level your vehicle. They also provide a more comfortable ride by absorbing road shock and improving roll stability. Easy to install and use.


  • Improves suspension, handling and safety
  • Provides additional support as needed, so you always get a smooth, comfortable ride
    • Allows the leaf spring ample movement and cushions light loads
      • Rides just as smoothly when you're not hauling a load
    • Becomes more rigid as more weight is added
      • Increases stability - gives you great performance when you are hauling heavy loads
      • Reduces rear sag
  • Works independently - side to side
    • Helps to compensate for off-center loads
    • Reduces body roll when you have to swerve or execute a sharp turn
  • Acts as shock absorber, taking the brunt of bumps and rough roads
    • Extends the life of your suspension
  • Includes 2 Aeon hollow rubber springs, custom-fit brackets and hardware for simple installation
    • Replaces axle bump stops on frame
    • No drilling required


  • Capacity: 7,000 lbs
    • Do not exceed your vehicle's weight-carrying capacity
  • Designed to work with a suspension system that is in good working order
  • Severe Duty should be used if a lot of weight will be towed long distance
  • Limited lifetime warranty - satisfaction guaranteed

An example of sag on a truck's rear axle under a heavy load. The Timbren Suspension Enhancement System levels the vehicle.

Whether you're hauling heavy loads in the cargo area or by pulling a trailer, you will often see the rear sag while the front end rises. In these cases, the rear axle is handling not only the weight of the cargo, but more of the truck's weight, as well. Because less weight is on the front axle, the front tires are making less contact with the road. Overall handling - traction, steering, and braking - is negatively affected. But the resistance from Timbren's Suspension Enhancement System works with your factory suspension to keep your vehicle level and improve your driving experience.

Diagram of the Timbren spring installed

The Timbren system has a custom-fit bracket that will be bolted onto each frame rail above the rear axle. Hollow rubber springs are bolted to the bottom of the bracket and hang down to where the bottom of the spring sits, one inch above the axle. The inch of clearance allows the existing factory suspension to operate normally under light loads and standard terrain, ensuring the smooth, comfortable ride that you are used to.

Animation of a standard Timbren rubber spring

Timbren Suspension Enhancement Systems are designed to work progressively. When the hollow rubber springs are compressed, the convoluted design causes them to quickly collapse along the folds. Once the folds are compacted, the stacked barrel shape increases resistance, stiffening the suspension and keeping the truck level.

Timbren suspension system works to prevent body roll

Each hollow rubber spring works independently to support the driver's or passenger's side of your vehicle. This is helpful when you swerve or make sharp turns. Each spring is activated when it is needed, so body roll is greatly reduced. The independent action also works well when you are hauling off-center loads.

An example of a trailers swaying

Because the vehicle handles better with the springs, less turbulence will be passed along to the trailer, and this helps to keep the trailer in line. Your driving comfort is further enhanced if the trailer does begin to sway (from a gust of wind or a passing semi), because the movement from the trailer is not transferred to the truck. This also works to make the sway subside more quickly.

An empty truck on a bumpy road without Timbren

Another great feature of the rubber construction is that the springs absorb most of the road shock, creating a smoother, more stable ride overall. Wear and tear on the factory suspension is also lessened because the rubber springs work to prevent bottoming out on rough roads.

Compared to the Competition

Timbren's suspension enhancement systems are much easier to install than air springs - there are no air hoses to run, no compressors or gauges to hook up, and no manual adjustments to make. The rubber construction makes Timbren's springs more elastic than similar products constructed of microcellular urethane. And more elasticity allows for a more comfortable ride because the rubber has more travel.

GMRTT15S Timbren Rear Suspension Enhancement System

Installation Details TGMRTT15S Installation instructions

This Product Fits The Following Vehicles

Customer Reviews

Timbren Rear Suspension Enhancement System - TGMRTT15S

Average Customer Rating:  4.7 out of 5 stars   (2191 Customer Reviews)

7,000-lb Capacity. These hollow rubber springs sit above the rear axle to help stabilize and level your vehicle. They also provide a more comfortable ride by absorbing road shock and improving roll stability. Easy to install and use.

2006 Chevrolet Silverado

Good product, good quality... 445617


When towing travel trailer, too harsh of a ride, like a log wagen. Bought air lift AL59565 and they ride great. 64976


Used product before worked as expected service very good. 429883


Great product, stopped sagging problem when pulling trailers 825371

2015 Chevrolet Silverado 1500

Very easy install... A little early to know how well it works. 546461

2016 GMC Sierra 1500

No instructions were included. I tried to find something on line but I couldn't find anything that looked like my kit. 501590

Sorry that instructions werent included. If you use the link provided, you can see or print the installation instructions.
-- Mike L - 04/28/2018



I ordered it late Monday received it Wednesday very fast turn around good price helpful customer service overall very pleased I installed it same day using it for a trip next day Thanks 43176

- TDF25004B

Review from a similar Aeon Spring System in Vehicle Suspension

I have a very heavy "Cattle Guard" on the front of my RAM 3500 and this combined with the heavy 4WD and diesel engine the extra support from the Timbren Front Suspension Enhancement System definitely keeps the front suspension from bottoming out. 644652

Working GREAT!!!!
Ron H - 05/24/2020



Review from a similar Aeon Spring System in Vehicle Suspension

I had bought these timbrens and the weight safe hitch with the 8” drop from etrailer. I was quite please by both products. Installation of the timbrens was very easy, only took 30-40 minutes to change out bump stops in my garage.I hauled a Uhaul trailer with a Jeep over 300 miles, with no issues. The timbrens worked great, no issues with the rife. And I really like the weight safe hitch. I recommend checking out these two products from etrailer. Thanks etrailer. 642864

Great no issues, made a couple trips out to California pulling heavy trailers, the hitch and timbrens are working out great.
David G - 05/17/2020



Review from a similar Aeon Spring System in Vehicle Suspension

Installed this on my 2009 Caravan because when I had a hitch mount 4-bike platform rack hanging off the back and was loaded with camping gear and family, the rear suspension was terrible, it would bottom out, and my headlights pointed up so that everyone would flash their brights at me. New shocks helped, but did not solve the problem. This product did fix the problem and I am very happy. I was concerned about the feel when the van us unloaded, but this has not been an issue. I highly recommend this product. 796869


Review from a similar Aeon Spring System in Vehicle Suspension

It was very easy to order this item from Etrailer. The item was delivered earlier than expected in strong packaging. Now for the Springs. I chose these because of the no drill install and reading a lot of reviews. I placed the springs on the rear axle of my 2018 Georgetown GT5 on the Ford F53 20,500lb chassis. It took around 20 min on my back but was easier than expected and I am 74. I have driven 1200 miles on the springs and I am more than happy with them, worth every penny. Side wind and passing trucks was almost eliminated, almost. 643899

Still going strong.I still feel that they were a great choice.
Joe T - 05/20/2020



Review from a similar Aeon Spring System in Vehicle Suspension

I installed these on my 2012 Ford F250 because I have two friends who have them on their trucks and they pull a travel trailer and a fifth wheel camper. I was impressed with the difference it made compared to my truck and camper Parked next to theirs'. I am mechanic and I see no reason why anyone would have trouble installing these them selves. Clean off the Nut and end of bolts before trying to loosen. Spray some WD-40 on the threads. Put on some gloves and use a 15mm wrench to loosen factory nut. Be sure to hold up on the factory bump stop because it has a line up pin that keeps it from turning as you loosen the nut. The driver side is a little more aggravating to get to because of wiring harness but there's plenty of room to use a wrench first then a 3/8" drive rachet and short extension with a good 6point 15mm standard depth socket will speed up removal. Then installing the new parts is a breeze. Just follow directions or etrailer videos on YouTube. Took longer to remove factory bump stomps than to install new ones. Maybe 45 mins total on original ones maybe. Then after preassembly of new ones, it took maybe 20 mins to install completely. Give yourself 1:30 hrs of time and enjoy your truck not sagging around town when loaded. 654107

I have had zero problems with the Timbrens on my truck. I have pulled our camper and several tag along trailers hauling equipment and parts. They do exactly what they are supposed to. Saves on sag by over an inch. No complaints here.
Lance M - 06/08/2020


- TDVR05096

Review from a similar Aeon Spring System in Vehicle Suspension

I carry 1400 pounds of tools and supplies in my NV200. These helped carry the load, along with heavier shocks. Very happy! 691745


Review from a similar Aeon Spring System in Vehicle Suspension

I had a problem with getting front sumo springs relative to the rear sumo springs I purchased earlier; however, the staff at etrailer were very helpful in getting me a suspension enhancement component made by timbren which I just installed. I believe the timbren supports are going to do the job I was looking for and make me just as happy as I am with the rear sumo springs. You will notice from the photos the supports make direct contact; however, the pictures were taken on a unlevel surface and when the truck is on a level surface the direct contact is equal on either side. Also, the timbren supports provide substantially more weight capacity in the event I choose to haul my scooter on the front end of the truck. Thanks again Derek S and etrailer staff I am very pleased with the service, customer relations and professionalism experienced when ordering my parts. Thank you, Bobby (Louisiana). 640223

The timbren springs are working out better than expected. I installled new Monroe matic RV shocks front and rear on my 2006 Chevy Silverado 1500 just prior to putting the timbrens on the front and the sumo springs on the rear and the ride is great especially with a load or hauling my travel trailer and the ride is just as smooth empty. I highly recommend the timbren and sumo springs because they fit by application and there is nothing additional to buy. Thanks etrailer.
Bobby L - 05/10/2020


- TFRTT1504E

Review from a similar Aeon Spring System in Vehicle Suspension

Functionally these Timbren Rubber Springs provide additional load capacity and reduce tipping while turning around corners on my F-150 as claimed; however, the set I purchased was overly stiff (I was only hauling 500 additional pounds). Timbren provided a replacement set with lower capacity which helped tremendously; however, it still rides slightly stiff. I wish Timbren or a competitor would provide these rubber springs in different durometers that provide 1000 lb increments to fine tune the suspension - reducing the over stiffness performance. 655944

The ride is still too stiff for my preference. I continue to be on the lookout for incremental rubber durometer springs that enable fine tuning suspensions.
Gerard G - 06/11/2020



Review from a similar Aeon Spring System in Vehicle Suspension

I debated for awhile weather or not to get this product or air bags. I chose this product for its value and high reveiws. I also like that it is maintenance free and lifetime reveiws. There is really nothing to go wrong except for the brackets to possibly someday get rusted. But the brakets seem to have a powder coat or really good paint. I installed these my self. Can be installed in a couple hours on a newer truck that has rust free u bolts. Just take the wheels off and jack the truck up and loosen u bolts and remove old bump stops and install the Timbren helper springs. I thought the hardest part was re torque the u bolts. The package I got had a one inch spacer which I installed. It made my helper springs about 3/4 inch below the bump stop. If I hit a good bump on the road I can feel them bottom out a little. Bit nothing that would change my mind about putting them on. I pulled my dump trailer since I put them on and it made a world of a difference. Very little squat and gave the truck a nice firm ride. I would recommend these to anyone that has a tight budget and wants a safer driving experience. 635935

Best thing for the money. Would buy them again. The only thing I would try next time is getting a bigger spacer from the factory so there is little to no gap between the frame and the rubber spring. I only had a little over a half an inc but by the time I put my camper on the truck look like it is starting to square.
David W - 05/14/2020



Review from a similar Aeon Spring System in Vehicle Suspension

I ordered timbrens for the front and rear of my chevy 2500. I have a 2000 lb truck camper and I wanted something to help carry the load a little better. I had no idea that my front bump stops had worn away to almost nothing until I installed these. They have worn well and performed well so far. 628835

Still working great. No problems. Really happy I didnt waste the money on airbags.
Josh - 04/16/2020



Review from a similar Aeon Spring System in Vehicle Suspension

Delivery by etrailer was fast. Their advice as to proper application of the Timbrens saved me lots of money! 749745


Review from a similar Aeon Spring System in Vehicle Suspension

So far they look great. I will put on this weekend and see how they work with my travel trailer. 476068


Review from a similar Aeon Spring System in Vehicle Suspension

My van is a 2000 GMC Safari. when pulling my 17 ft. boat it would sag pretty bad. after installing the Timbrens it sits level and isn't bottoming out anymore. Great product and great service from etrailer. The Timbrens went on very easily and the instructions were good. 122042

Van gave out about 2 months after installed them, didnt notice much difference except van road rougher. It was an older van and might have done better with new shocks.
Dan J - 03/25/2015


With this Timbren System installed you may notice a difference in the ride quality of the van when the Timbren springs are not activated. The benefits of Timbren suspension enhancement systems are designed to provide additional support when there is a load placed on them and on the vehicle suspension.

-- Rachael H - 5/4/2015


Review from a similar Aeon Spring System in Vehicle Suspension

These arrived as scheduled. The look good, well made. On my way out to install them now. The will get tested later today on the way to the lake. 703241

- TDR1500DQ

Review from a similar Aeon Spring System in Vehicle Suspension

This was ordered because the truck seemed overloaded with just s few items. I haven't installed it yet but will let you know how it works after I do The shipping and packing were excellent and arrived quickly. 420483

Working great.
Glenn L - 08/15/2018


- TDR1500DS

Review from a similar Aeon Spring System in Vehicle Suspension

Great product. 597716

- TDR1500DS

Review from a similar Aeon Spring System in Vehicle Suspension

Doesn't get any easier for an install. A jack, some soapy water and a couple pieces of 2x4. In about 5 minutes you're done. Took out almost all sag when I dropped my travel trailer on the ball. Great addition to the suspension. 488109


Review from a similar Aeon Spring System in Vehicle Suspension

Fast shipping 400467

Show More Reviews

Ask the Experts about this Timbren Vehicle Suspension

  • Is There a Timbren Rear Suspension Enhancement Kit that Fits 2006 Ford F-150
    We have a rear suspension enhancement kit from Timbren that fits your 2006 Ford F-150 4x4 with the part number TFR150D but the kit you mentioned does not fit.
    view full answer...
  • Timbren Rear Suspension Enhancement System TGMRTT15S Height
    The Timbren Rear Suspension Enhancement System part # TGMRTT15S for the 2000 GMC Sierra 1500 springs themselves measures 3-1/4" tall. If you use the spacer the spring will be 4-1/4". Timbren does require 1/2" and 1-1/2" between the rubber spring and the contact point when not loaded down.
    view full answer...
  • How to Remove Rear Axle Bump Stops on 2014 Chevy Silverado 1500 4x4
    All of the Timbren and other rear-axle jounce-spring kits we have for your 2014 Chevrolet Silverado 1500 4x4, shown on the linked page, feature a bolt-on installation. If you refer to the linked page for Timbren kit # TGMRCK15S you will see in the product image photos three diagrams showing different installation methods, including the one I linked for you, which shows a cup-type mount as found on 2007-2008 model years. Your truck should be a bolt on, however. A socket extension will be...
    view full answer...
  • Comparing Timbren Suspension Enhancement for 2019 Chevy Silverado 1500
    The difference between the two Timbren Suspension Enhancement Kits that fit your 2019 Chevy Silverado 1500 is that the Timbren # TGMRCK15S are designed to support daily driver trucks for towing and heavier loads, while the other option, part # TGMRTT15S, is designed for service vehicles like a tow truck. The reason for that is their design, with the service vehicle option being much more rigid and stiff for that type of work. Due to that, for your 2019 Chevy Silverado 1500, I highly...
    view full answer...
  • Timbren Suspension System Recommendation for a 2014 GMC Sierra 1500
    The difference between the two Timbren systems you referenced is the application for each. The Timbren Rear Suspension Enhancement System - Severe Duty # TGMRTT15S is designed for service vehicles only so it would not work for you. The # TGMRCK15S would make an excellent choice for a suspension enhancement system for your vehicle. This system has plenty of capacity for the ton of pellets you carried, and is great because when your vehicle is unloaded your ride quality will be exactly...
    view full answer...
  • Suspension Enhancement Recommendation for 2017 Sierra Towing Fifth Wheel Trailer
    For your 2017 GMC Sierra 1500 towing a fifth wheel trailer the best option we have for suspension enhancement is the Timbren kit part # TGMRTT15S as it will provide you with an additional 7,000 lbs of suspension support when needed. The air bag kits for your truck aren't designed for fitting with an in-bed fifth wheel or gooseneck hitch so I would not recommend that route.
    view full answer...
  • Can Timbrens be Used with Roadmaster Active Suspension Kit on 2011 Chevy Silverado
    For your 2011 Chevy Silverado I recommend starting with the Roadmaster Active Suspension Kit # RAS4611 that you mentioned by itself to see how everything handles when pulling your 34 foot trailer. It wouldn't necessarily be "overkill" to add the Timbren Rear Suspension Enhancement System # TGMRTT15S (the two components can indeed be used together) but maybe more accurate to say that the Timbrens might not really be utilized if the RAS is doing its job. Because the Timbrens will replace...
    view full answer...
  • Suspension Enhancement Recommendation 2001 Chevy Silverado 1500
    There aren't any products out there that will give you additional towing capacity. We have suspension enhancement kits for your 2001 Chevy Silverado 1500 like the # TGMRTT15S which will help the vehicle carry it's capacity in a safer manner.
    view full answer...
  • Timbren Suspension Enhancement for a 2008 Chevy Silverado with a 5th Wheel Trailer Hitch
    The Timbren system, # TGMRTT15S, installs on the bottom of the frame. As long as the 5th wheel bracket does not wrap around to the bottom of the frame it will not interfere. Timbren lists this kit as a fit for service vehicles only. I have included a link to the installation instructions for you to view. For a non-service vehicle, use # TGMRTT15S. It installs the same way and will not interfere. I have linked instructions for this kit as well as a link to our FAQ article on Timbren systems...
    view full answer...
  • What is the Warranty on the Timbren Rear Suspension Enhancement System
    The warranty of this Timbren Rear Suspension Enhancement System # TGMRTT15S is for the lifetime of your vehicle as long as your vehicle is under normal use. It is hard to say exactly how long it would take for you to install the # TGMRTT15S on your 2011 CHevy Silverado, but after looking at the instructions I would imagine it would not take you more than an hour as long as you have basic mechanical skills and access to tools. I attached installation instructions for this product for...
    view full answer...
  • Why Would Trailer Brakes Lock Up When Running Lights are On
    There's a short on your trailer wiring between the running light circuit and the brake output circuit that runs to the trailer brakes. Look for exposed wire or corrosion on the wiring and connectors and you'll find the short. Rear suspenion enhancement like the Timbren kit part # TGMRTT15S would be a great way to help with towing. It will give more more support to the rear suspension to allow it to tow level.
    view full answer...

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality vehicle suspension for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate vehicle suspension information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Written by:
Tyler C
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Adam R
Installed by:
Jeff D
Installed by:
Robert C
Video Edited:
Jacob T
Updated by:
Mary E
Video by:
Jonathan Y

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time.