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Timbren Suspension Enhancement System - Rear Axle
Part Number: T28MR
In Stock
$269.36
Retail:$316.90
You Save: $47.54
2023 Keystone Sprinter Fifth Wheel
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Timbren Vehicle Suspension - T28MR
Highlights
- Custom Fit for Your Vehicle: Mounts to existing attachment points
- 8,600-lb Load Support: Keeps your truck level and stable when towing or hauling heavy loads.
- Protects Steering and Braking: Prevents rear sag so handling and braking stay consistent.
- Smoother, Safer Ride: Rubber springs absorb bumps and rough roads to reduce body roll and sway.
- No Upkeep or Adjustments: Works automatically with your factory suspension, no air lines or PSI to set.
- Simple Bolt-On Install: Mounts to the frame with included brackets and hardware, no drilling needed.
Features to know about
Keep the Rear End Level and Stable: 8,600-lb Load-Leveling Support
When heavy cargo or a trailer pushes your rear suspension down, handling and braking can suffer. The Timbren Suspension Enhancement System adds up to 8,600 lbs of load-leveling support above the rear axle. The hollow rubber springs grow more rigid as weight increases, keeping your ride level and controlled. You’ll notice steadier steering, better traction, and balanced braking even when the bed or hitch is loaded down.
Smooth Out Rough Roads Under Load: Progressive Rubber Spring Design
Bumps and potholes hit hard when your suspension bottoms out. These Aeon hollow rubber springs act like built-in shock absorbers, taking the brunt of road impact so your factory suspension doesn’t have to. The unique convoluted design compresses in stages—soft at first, then firmer as it stacks—delivering a smoother, more stable ride under heavy loads without harsh rebound.
Stay Steady in Crosswinds and Turns: Independent Spring Action
When wind or cornering pushes one side of your vehicle harder than the other, each Timbren spring works on its own to counteract body roll. That side-to-side independence keeps the vehicle planted through turns, over uneven ground, and when towing off-center loads. Even if a trailer sways behind you, the motion is dampened faster so both truck and trailer track straight again.
Install It Once and Forget About It: Simple Bolt-On Setup
You don’t need compressors, airlines, or adjustments to get solid load support. The kit includes two custom-fit brackets, Aeon springs, and all mounting hardware for a straightforward bolt-on installation—no drilling required. Once installed, the system automatically engages when weight is added and stays out of the way during normal driving. It’s a durable, maintenance-free solution that extends the life of your suspension and keeps your ride confident trip after trip.
Specs
Weight and Capacity
- Load-leveling capacity: 8,600 lbs
Warranty
- Warranty: Lifetime warranty
Note
Timbren springs will not increase your vehicle's weight-carrying capacity. Do not exceed the manufacturer's recommended weight limit.
GMRS15 Timbren SES with Aeon Hollow Rubber Springs - Rear Axle
This Product Fits The Following Vehicles
- 2019 - 2026 GMC Sierra 1500 2 Wheel Drive
- 2019 - 2026 GMC Sierra 1500 4 Wheel Drive
- 2022 - 2022 GMC Sierra 1500 Limited 2 Wheel Drive
- 2022 - 2022 GMC Sierra 1500 Limited 4 Wheel Drive
- 2019 - 2026 Chevrolet Silverado 1500 2 Wheel Drive
- 2019 - 2026 Chevrolet Silverado 1500 4 Wheel Drive
- 2022 - 2022 Chevrolet Silverado 1500 LTD 2 Wheel Drive
- 2022 - 2022 Chevrolet Silverado 1500 LTD 4 Wheel Drive
Customer Satisfaction Score:
95% were satisfied with this product
5% of customers were not satisfied
- Product did not meet expectations
- Wrong item was ordered
- Did not arrive in time
Ratings & Reviews
4.7
7305 reviews
by:
Bud
07/08/2026
Stiffens and corrects kneel in rear end of 2023 Chevy Silverado 1500. You will notice a stiffening of the rear end suspension while unloaded, but it’s a fair trade off to prevent sagging and porpoising while towing. I found it easier to pull the rear wheels and work from the side than underneath the vehicle while installing.
by:
Kevin
04/23/2026
gmc
Sierra
The install was quite simple(GMC Sierra 1500 Elevation), haven’t towed with them yet so I can’t really say how they work, but I can say that they are night and day difference from the factory…
Mike L.
4/23/2026
Thanks for that comparison photo, Kevin. That does an excellent job of showing folks the difference!!!
by:
Mark D
09/01/2026
2025
Chevrolet
Silverado 1500
The product should be ok. Timbren's decision to sell a package that 'fits' my truck when it really doesn't and their answer if for me to buy additional items from them is not acceptable. Company clearly doesn't stand behind their product. Said it fit on their own website. etrailer's fitment tools are also lacking but their customer service is understanding.
by:
Coolhand
03/12/2025
Installed in about a half hour, ez to do. Have put 1000 lb load in bed, stopped the sag, towed my dump trailer yesterday - big difference in handling with load. I installed with recommended 1.5" of clearance between Timbren and spring mount, so the suspension can work normally in driving, and only engage when loaded. Very satisfied with the product
Gwendolyn Y.
3/13/2025
Hey neighbor! I'm glad to hear that everything is working so well for your needs. What kind of loads are you hauling?
Coolhand
3/13/2026
Worked great, stable towing and hauling, ended up trading 1500 for 2500 for larger loads and trailers
by:
Bryan
10/12/2026
2023
Chevrolet
Silverado 1500
Easy to install.
Helped eliminate truck squat, while towing trailer
Helped eliminate truck squat, while towing trailer
by:
James
09/02/2026
Every time you hit a bump, it slams into the suspension system
Christopher H.
9/3/2026
These are quite a bit larger than the factory bump stops so they will be making more frequent contact even with your Silverado unloaded. I'm not sure how you installed these but you are able to remove the included rubber spacer and reinstall them with included shorter bolt. This would reduce the height some and hopefully eliminate some of that contact.
Christopher H.
9/3/2026
@JimP Anything that replaces the bump stop is going to be the most noticeable during unloaded driving, Timbrens being the biggest culprit. Sumo springs are a little more forgiving as they're made of a poly material as opposed to the dense Timbren rubber. Were you trying to correct sagging issues during hauling? If so, what are you usually hauling?
by:
Terry
08/05/2026
chevrolet
Silverado
I installed on my 2026 silverado. I am pulling a travel trailer and they made a world of difference. The sag was so much less noticeable. I really don't know why such small bump stops are installed in the first place.
by:
Paul Zachos
11/01/2026
Haven’t towed yet but an easy install if all spacers were included. Didn’t like reordering should have sent correct spacers for my truck
by:
George
07/26/2026
Got a new camper trailer and the front of the truck was rising, got the timbrens put on and it's smooth sailing now
by:
Michael
02/21/2024
2022
Chevrolet
Silverado 1500
Just received the box and appears that everything is there. Might want to think about putting some tape on the box to seal it as the parts came in the original box and nothing else. The tab closing the box was barely keeping it closed.
As far as the parts go this is my second set. Had very good luck when I had them on my last truck so I am looking forward to similar results. Easy to install and function as described. Would never use airbags again!
As far as the parts go this is my second set. Had very good luck when I had them on my last truck so I am looking forward to similar results. Easy to install and function as described. Would never use airbags again!
Michael
2/21/2025
They work great! Drove cross country pulling the trailer and the Timbren mounts made for a stable ride. Took out all of the bouncing and a lot of the sway! Highly recommend this product and would definitely choose these over air bags.
Jesse M.
2/21/2025
@Michael Nice! Glad to hear you are happy with your Timbrens. I am sure they will continue to serve you well for years to come. Do feel free to reach out anytime you need anything else :)
by:
Gordon
06/17/2026
Had them for a year and barely installed them this week. No camping or hauling the past year kept me from install. Installation was 20 minutes and very easy. Loaded it helped reduce the sag in the rear with my 23 ft trailer at 6k approx weight
by:
Robert
08/05/2026
2026
Chevrolet
Silverado 1500
Was very pleased with updates from order placement to receipt. Simple installation. Have not yet pulled loaded trailer so can't address performance yet.
by:
Randy
09/24/2026
It’s almost like as soon as closed the page and got up y’all had my order in a box ready to go. If everyone had service like you guys life would be good. Keep up the great job.
by:
Larry V
08/02/2025
Box came very beat up, but all parts were there. Unluckily broke one of the factory bolts so that should be fun tomorrow when I remove that broken bolt. Other than that works as designed and hopefully improves as described.
by:
Steve
05/02/2026
Rides is like I put a piece of wood between my axle and frame. Sure I guess it would be better to tow a trailer but there is no in between
by:
Aaron
06/26/2026
Box was damaged during shipping before the post office got it, but I think everything was OK
by:
Lorne
03/15/2026
2025
Chevrolet
Silverado 1500
Very easy to install on my 2025 Silverado. Unloaded, the ride seemed normal. Under a full load, the ride was a bit stiff, but not unexpected. Really helped get rid of the rear end sag with the trailer hatched up. I’m very happy with them.
Kate F.
3/18/2026
Glad to hear it didn't change the unloaded ride quality Lorne!
by:
Nick
06/09/2026
They work and reduce squat, definitely stiff and feel the road when loaded down with a trailer.
by:
Tony
04/23/2026
Easy install, great result - no more drag on Truck bed and travel trailer sits straight. Also got better gas milage (did not see that coming)
by:
Mark
09/04/2026
2023
chevrolet
Silverado
Installed on a 2023 Silverado 1500 , install was super easy... I used the full bumper and I have yet to pull a trailer with it, but no trailer and empty bed it rides a little rougher , but not bad ..
.
.
by:
William
01/30/2026
First I installed the bump stops with spacer with no load it,my vehicle road rough.So I took out the spacer it gave an inch clearance with no load, it road better but you can feel your truck over any rough road. I wish they wouldn't not touch frame without load. So I will take them off my truck. Under load it was better not much sag.
by:
Herman
09/29/2026
Got and installed them today, I’ll let you know as soon as I drive some with them on and with a load of water.
by:
Russ
04/26/2026
These guys at etrailer are first class great service, I go to them for anything I need
by:
James
05/24/2025
Very well made product and great communication.
James
5/25/2026
Ok, I did remove the optional spacer. With spacer installed I was getting a very hard harsh ride. Once removed it was fine.
by:
Zachariah
07/17/2026
Easy install. Really improved towing performance. However the ride quality suffers when unloaded and is quite harsh.
25
7305
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view full answer... - Will The Timbrens Affect My Ride Quality When Not Hauling a Heavy Load?Hello Ken, The Timbren Suspension Enhancement System - Rear Axle # T28MR is a great option for hauling a heavy load. If you are worried about ride quality, might not be the best option. Bump stops are great when they are needed as they will protect your vehicles suspension when needed. However, when you are not hauling a load they can cause a rough ride. If you hit a pot hole or bumps in the road it can cause a bit of a jolt when it hits the frame. If you are looking for a little bit...
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view full answer... - What Timbrens and Spacer do I Need for My 2025 Chevrolet Z71 Trail Boss?Hello John, Welcome to etrailer, I'm glad you found us! I see that you went ahead and ordered the Timbren Suspension Enhancement System - Rear Axle # T28MR, which is a great choice for your 2025 Chevrolet Silverado 1500 Trail Boss. You probably wrote in because we currently have these listed as not fitting the Trail Boss. I confirmed directly with Timbren that they will indeed fit your Trail Boss, and I am getting our fitment information updated. Since your Trail Boss has the factory...
view full answer... - Recommended Air springs for a 2025 Chevrolet Silverado 1500 W/ Adaptive Ride ControlKurt, it looks like the reason the AirLift Air Springs won't work with the adaptive ride control because of the way the springs install in the suspension, but the good news is that there is an alternative; the Firestone Ride-Rite Air Helper Springs # F2609, which will work. These springs have a load leveling capacity of 5,000 lbs, an adjustable air pressure range of 5-100 PSI, and has a simple no drill install.
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view full answer... - Timbren Rear Suspension Enhancement for a 2019 Chevy Silverado 1500Hi Gary, Yes, the Timbren Suspension Enhancement System, part # T28MR, for your 2019 Chevy Silverado 1500 is backed by Timbren’s 100 day money back guarantee as well as their limited lifetime warranty. That gives you a nice opportunity to actually put them to work on your truck and make sure you’re happy with how they perform. Timbren is also a really good company to work with if you ever have a question or run into an issue. During those first 100 days, they’ll work with you to troubleshoot...
view full answer... - Will Timbren Bump Stops Work w/a 2021 Chevy Silverado 1500 LT Z71 w/a 3.0L Duramax Engine?They sure will Colin. The Timbren Suspension Enhancement System item # T28MR is exactly what you need for your 2021 Chevy Silverado 1500 LT Z71 with the 3.0L Duramax engine. They didn't start putting the adaptive ride control in that trim package until the next model year so there's no compatibility issues. The Timbren SES item # T28MR is going to replace your rear factory bump stops. The new hollow rubber springs have a 8,600 lbs capacity that will support your rear end when you're towing...
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view full answer... - Recommended Suspension Enhancement for a 2025 Chevrolet Silverado 1500 LT W/ 2" Rear BlockHey Levi, for your 2025 Chevy Silverado 1500 LT I recommend going with the Timbren Suspension Enhancement System # T28MR. These springs require no maintenance, has an easy install with no air lines necessary, and is great for consistent loads, like your trailer. Timbren does also offer a spacer kit # A25723-90AH00 which you can stack two to cover distance of the 2" block in the rear. Let me know if there is anything else I can do for you, please feel free to let me know!
view full answer... - Is There Spacer Kit for Timbrens that Fit 2024 Chevy Silverado 1500 LTHey Tony, with the Timbren kit part # T28MR that fits your 2024 Chevy Silverado 1500 that has a 2 inch lift you'd need a quantity of 4 of the 1 inch spacers part # A25723-90AH00 and you'd be set. Is it sagging when you are towing?
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view full answer... - What Timbren Rear Suspension Springs Fit a 2024 GMC Sierra 1500? The Timbren Suspension Enhancement System # T28MR is the kit which will fit your 2024 GMC Sierra 1500. Do understand this is a very heavy duty spring with a weight capacity of 8,600lbs. This will most likely give you a less than desirable ride quality. Instead I recommend checking out the SumoSprings in a 1,000LB # SS65FR or 1,500LB # SS45FR capacity. These are much more inline with the weight capacities of your Sierra. And as these are a progressive material it will not be as harsh of...
view full answer... - Timbren or RAS for a 2021 Chevy Silverado 1500 Pulling a Trailer The Timbren Suspension Enhancement item # T28MR and the RoadActive Suspension item # RAS54FR can both be used in tandem on your 2021 Silverado 1500 but I wouldn't recommend it. The Timbrens are great to reduce sag but they only engage when your suspension is weighed down so there will still be some sag no matter what. Timbren's are also bouncy and will negatively affect the comfort of your truck's suspension when you are not towing. I recommend only using the RoadActive Suspension item...
view full answer... - Are Spacers Needed for Timbrens on 2021 Chevrolet Silverado 1500 Z71 Trail BossYes, the Timbren Suspension Enhancement System # T28MR will be the best option when it comes to cost-effectiveness. This will fit with your 2021 Chevrolet Silverado 1500 Z71 Trail Boss but you'll want to make sure these fit the gap properly. The Timbrens measure 5-5/8" high overall and you need a gap of 1/2" to 1-1/2" for the Timbrens to be effective. If you find that you have more than 1-1/2" of a gap then you can use the 1/2" Spacer # TA25722-90P00 and the 1" Spacer # A25723-90AH00 as...
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view full answer... - Recommended Suspension Upgrade for a 2023 GMC Sierra 1500 Congrats on the new truck! The Timbren item # T28MR will work and it'll keep the rear end of your 2023 GMC Sierra 1500 from squatting but they're also going to give you a rough ride when you are not towing or have your camper. They're just a solid piece of rubber and they don't have much give to them. I recommend using the SumoSprings Solo Custom Helper Springs item # SS45FR instead. These have a 1,500 lbs capacity and only engage when there is weight added to your truck. When you are...
view full answer... - Correct Timbren Suspension Enhancement For 2021 GMC Sierra 1500 AT4I reached out directly to Timbren for you, and they told me the correct fit for your 2021 GMC Sierra 1500 AT4 was indeed the Timbren Suspension Enhancement System # T28MR.
view full answer... - Comparing Timbren Suspension Enhancement For a 2023 GMC Sierra 1500The Timbren Suspension Enhancement System # T28MR is designed for your 2023 GMC Sierra 1500 both for heavy loads and unloaded. Do note that unloaded ride quality will be more stiff. The Timbren System # T53MR is their severe service kit. This is designed for vehicles that will always be carrying heavy loads. If you are adding a service bed, slide in camper or salt spreader this is the better option. Without a heavy load on the suspension you will notice a much stiffer ride for the rear...
view full answer... - Comparing SumoSprings and Timbren Springs For a 2023 GMC Sierra 1500 Personally I feel the SumoSprings Solo Custom Helper Springs # SS45FR are a better option for your 2023 GMC Sierra 1500. These are not as stiff as the Timbren Springs # T28MR and will not cause such a harsh ride when not hauling additional weight or under light loads. These particular SumoSprings are rated for 1,500lbs which is more in line with the payload capacity for your Sierra. The Timbrens are rated for 8,600lbs which is far more than your truck would ever be able to carry.
view full answer... - Will The Timbren Suspension Enhancement Fit a 2024 Chevrolet Silverado 1500 ZR2? While I can confirm the Timbren Rear Suspension Enhancement # T28MR will fit your 2024 Chevy Silverado 1500 ZR2, I would be hesitant to put such a heavy spring on your truck. I would personally select the SumoSprings # SS65FR as these will actually help to absorb road shock where the heavy Timbren's would transfer it to the truck. I only like using Timbren springs on very heavy duty applications such as trucks with a plow or work box in place of the bed.
view full answer...
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Condition: Installed
Notes: Item has been previously test fitted and has cosmetic signs of use.
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Kate F.
7/13/2026
Bud, thank you so much for taking the time to leave a review! I'm glad to hear the suspension upgrade helped reduce the sagging and porpoising while towing. I also really appreciate you including the installation pictures and sharing your tip about removing the rear wheels. I'm sure that will help the next person tackling the install. Thanks again for choosing etrailer!