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Timbren Suspension Enhancement System - Rear Axle

Timbren Suspension Enhancement System - Rear Axle

Item # TFR350SDJ
Our Price: $373.07
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Vehicle Suspension

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8,600-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. Great Prices for the best vehicle suspension from Timbren. Timbren Suspension Enhancement System - Rear Axle part number TFR350SDJ can be ordered online at or call 1-800-940-8924 for expert service.
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Timbren Vehicle Suspension - TFR350SDJ

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

8,600-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 have a smooth, comfortable ride
    • Allows the leaf spring ample movement while cushioning light loads
    • Becomes more rigid as more weight is added for a great performance when you're hauling a heavy load
      • Increases stability
      • Reduces vehicle sag
  • Works independently - side-to-side adjustment
    • Helps compensate for off-center loads
    • Reduces body roll when swerving and turning corners
  • Acts as a shock absorber, taking the brunt of bumps and rough roads
    • Extends the life of your vehicle's suspension
  • Includes 2 Aeon hollow rubber springs, custom-fit brackets, and hardware for simple installation
    • Installs directly onto frame
    • No drilling required


  • Load-leveling capacity: 8,600 lbs
    • Timbren springs will not increase your vehicle's weight-carrying capacity. Do not exceed the manufacturer's recommended weight limit.
  • Lifetime warranty
  • Satisfaction guarantee

An example of sag on a vehicle's rear axle under a heavy load

Whether you're hauling heavy loads in your bed or cargo area or you're towing a trailer, you will often see the rear of your vehicle sag while the front end rises. In these cases, the rear axle is handling not only the weight of the cargo, but also more of the vehicle's weight. 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 comes with custom-fit brackets that are 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, 1" 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 your vehicle level.

Timbren suspension system works to prevent body roll

Each hollow rubber spring works independently to support the driver's side 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 your vehicle. 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.

Timbren Suspension Enhancement 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.

FR350SDJ Timbren SES with Aeon Hollow Rubber Springs - Rear Axle

Installation Details TFR350SDJ Installation instructions

This Product Fits The Following Vehicles

Customer Satisfaction Score:

Customer Reviews

Timbren Suspension Enhancement System - Rear Axle - TFR350SDJ

Average Customer Rating:  4.7 out of 5 stars   (5572 Customer Reviews)

8,600-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.


These keep my truck level with my slide in camper on board. It no longer rests on the helper springs. I have gained over 2” of height on the bed. Super easy to install. They also are noticeable on corners. Not nearly as much lean.


Took about 45 minutes to install. But that was 2 trips into the house cause my deep drive sockets were buried. F-350 gasser with 8’ box, Fiberglas cap, 200lb wooden storage drawers and estimated 400lbs in tools. I tow a 14k bumper pull dump that squats the truck. I installed the spacer with the timbrens and it sits on the original axle stop. Ride quality is unknown as I haven’t driven it yet.

2021 Ford F-350 Super Duty

These are great!! Removed the sideways motion in curves, removed the front/back rocking motion when crossing interstate bridge joints, and made the truck level with the camper attached. Simple installation as well.



Product is still working great. No cracks or tears in the rubber. Still softening the bumps on the roads.

Etrailer Expert

Mike L.


@Sean Glad to hear your # TFR350SDJ Timbren Helper Springs are working well for you!


It looks like they are going to do the job. Easy install even had to take one back off to remove spacer. Gained back at least 1-1/2. Truck sits at least an inch off overloads. Little pricey I think for what they are but lot cheaper than air bags. Need to take after photo in day light.
2023 F350


This is an absolute MUST have item if you are hauling with your truck. Hands down the best investment in suspension technology. No sag thanks to the addition of the 1” spacer. My 24,000lb triple axle 5th wheel with a pin weight os 4,000lbs is towed effortlessly from a single axle F350 cross country with no sag at all. My truck sits absolutely level. The helper leaf springs are not engaged and the truck is smooth and extremely stable, even without sway bars!!

Love and highly recommend this product to every SuperDuty owner i meet.

Best investment ever.

2019 Ford F-350 Super Duty

We travel full time in our fifth wheel camper. I installed these Timbrens on our 2019 F350 and they perform great! Keep our truck sitting level with camper hooked up. They also help improve the ride while traveling.



Excellent! Have sold that truck and have a new F 350 but purchased a dually this time. And yes we installed Timbren on it as well.


Super easy to install. etrailer video madder it even easier. Great shipping and service.
Helped with my 5th wheel hauling!



The Timbren suspension really makes a difference over the factory bump stops when hauling our 5th wheel. The truck is not rear heavy and drives significantly better. Its a great safety device and doesnt reduce the ride quality when hauling. Id HIGHLY recommend these to anyone who is hauling a load. Great product, too bad the manufacturers dont use these in the stock trucks!!


Perfect fit. Installation was pretty easy. Took me about an hour for both sides.

Pontiac Montana

This helped prevent the squat in my F-350. It also made the truck more stable when towing. I tow a 44' Montana fifth wheel. I don't even know they are installed when driving with no load. I love them!

2022 Ford F-350 Super Duty

Installation was simple, took all the squat out of my 2022 F350 when pulling a goose neck 3 horse living quarters horse trailer


We are full time RV’rs and travel every 7-14 days and these Timbrens have been awesome, put them on and forget about them, you never have to worry about airing up air bags! Highly recommend to anyone close to their payload. We have towed about 7,000 miles this year with them.

2018 Ford F-350 Super Duty

Product was easy to install, 1/2 hr taking my time. Used a open end wrench and floor jack. My 2018 F350 Super Duty Super Cab 4wd no longer plunges over bumps, it has lost all its rear end sway on turning, carries my load much smoother ( loaded all the time ). Even with the load I always carry, the vehicle sits 1” higher in the rear. Prior to the install I was constantly hitting the rubber stops on my factory overload springs.



Excellent! I have since purchased another set from you for a 2019 F350 diesel. These things are just the ticket! The ride and handling is so much better!

2019 Ford F-350 Super Duty

Very easy to install and works well. Truck does not squat as much with a heavy trailer so you may need to adjust trailer hitch to insure trailer is at desired "levelness".


The Timbren SES is an awesome upgrade to help with sagging and stability when pulling a heavy load. Bolted right up with zero issues. Took about 30 minutes to install. The tech support at etrailerb are most helpful and the package tracking info is great.

Ford F-350 Super Duty

Purchased this product for my F350 to help reduce bouncing when towing 5er on rough roads (e.g., I95 in SC). The Timbren’s exceeded my expectations and I also gained about 1/2 inch in towing bed height. Overall very pleased.

Rachel M.


I remain very pleased with the Timbrens performance.


Eliminated the bounce and instability associated with driving over really crappy interstate roads, especially the highway bridge transitions!


Product was as described. Customer service keep me informed on the shipping and delivery progress.
Etrailer has always been great for me.


Great product! I had some body sway, and a little sag when loaded heavy in my F350. I have a steel flat bed so my pickups not empty when empty, these fixed my issue of it being squishy till the factory overloads kicked in.

Made the ride solid and firm, exactly what I was looking for. Makes corners great again for a heavy duty pickup, only thing a person may want to consider is if you have a heavy bed or loaded with tools, you’ll have to pick up the rear end to unload the springs enough to slip the timbren in.

Cant wait to get hooked up to the Rv and our dump trailer and see how much better it trailers, especially since it exceeded my expectations empty.

2019 Ford F-350 Super Duty

So easy to install on 2019 F350 SD Dually. just lift the back an inch by the hitch and can work right over the tires. no need to get dirty under the truck. I only drop 1.5 inches with my current fifth wheel, so these will just come into service when i load then family. Installed in less than 30 minutes.

2014 Ford F-350 Super Duty

I ordered these for my 2022 F350 SD because I haul a 14,500 lbs 5th wheel camper and didn't want air bags. Ordered them, arrived in four days and installed as the directions said. Installed in 30 minutes after removing the factory bump stops. Easy as can be. No ride difference without the 5th wheel attached as they don't make contact until loaded. I loaded 5th wheel camper and noticed right away the truck didn't sag like originally. I would recommend and purchase again if I purchased another truck.


Absolutely excellent service delivery was on time and product is exactly what I needed. I shop in trailer because the description that you read is what you get when you receive your product.


Easy enough for someone like me to install, you do not know they are there when you are running without a load on. With my fifth wheel on, super smooth ride.


The order came promptly and was delivered in perfect condition. As indicated by others, they were easy to install and I installed them in twenty minutes. One of your other customers stated if you jack up the rear of your truck you can work over the rear tires without having to crawl under the truck. It worked perfectly! The pictures are of jacking up the truck, working over the tires, and final installation.


My wife and I are full time RVers. We bought these to take some of the sag out of the rear of the truck.

Installation was a breeze. Very straightforward. The function has been excellent.

They work so well and require so little maintenance and attention that you’ll forget you even have them on the truck until you get an email asking you how they’ve been for the last year ??

Excellent product, excellent service from E trailer. 100% recommend.

2017 Ford F-350 Super Duty

added these to help with weight carrying on my F350 dually. Installed easily and doesn't really change the empty ride quality.

Show More Reviews

See what our Experts say about this Timbren Vehicle Suspension

  • Will Timbren Rear Suspension Enhancement TFR350sdj fit 2022 Ford F-350 Dual Rear Wheel?
    They sure will! The Timbren Suspension Enhancement # TFR350SDJ you were looking at will work perfectly on your 2022 Ford F-350 Super Duty Dual Rear Wheel and will provide up to 8600lbs of load leveling support to keep your truck's suspension from sagging because of a heavy payload or heavy trailer. I included a video of the # TFR350SDJ for you to take a look at.
    view full answer...
  • What Rear-Axle Timbrens do You Recommend for My 2022 Ford F-350 4x4?
    For a great Timbren system that works with your 2022 Ford F-350 4x4, I recommend the Timbren Suspension Enhancement System - Rear Axle # TFR350SDJ. Apart from giving you a 8,600 pound load-leveling capacity, the Timbrens reduce vehicle sag and reduces body roll when swerving/turning corners. Also, one of the great things about the Timbrens is that it allows for a smooth ride even when you're not hauling a load.
    view full answer...
  • Will Adding The Timbren Suspension Enhancement Provide Any Extra Benefit
    Yes, adding the Timbren Suspension Enhancement System - Rear Axle, part # TFR350SDJ, will provide stability to your suspension. It will be a fail safe to keep your 2017 Ford F-350 Super Duty level when you are towing your 5th wheel. Your suspension will not bottom out with the addition of the Timbren Suspension Enhancement. It will not only help while you are towing your 5th wheel, it will help if you ever carry heavy items in your truck bed. However, after speaking with a Timbren rep,...
    view full answer...
  • Timbren Rear Suspension System Clearance on 2020 Ford F-350
    According to Timbren's installation manual for the Suspension Enhancement System # TFR350SDJ, when these are installed on medium and heavy-duty trucks, the springs will be in constant contact and have no gap. To install these, you will need to use a jack to lift the vehicle's frame to provide some clearance between the frame and the axle. Check out the video linked below for installation details.
    view full answer...
  • Dimensions of Timbren Suspension Enhancement Spring for a 2018 Ford F-350
    From the top of the bracket to the bottom of the rubber spring the # TFR350SDJ Timbrens measure about 7-1/2 inches. When installed you ideally want about a 1/2 inch to an inch of space between the Timbren and its contact point. However, to install them you will be removing your bump stop. So make sure you measure where the bump stop mounts.
    view full answer...
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  • Compatibility of Timbren Suspension Enhancement With 2022 Ford F-350 Super Duty FX4
    The Timbren Suspension Enhancement System - Rear Axle # TFR350SDJ will fit your 2022 Ford F-350 Super Duty FX4. These will help increase stability and reduce vehicle sag when you're towing or hauling a heavy load. They work independently to help reduce body roll and compensate for off-center loads. The # TFR350SDJ installs directly onto the frame and will not interfere with your FX4 off-road package. I have attached an installation video for your reference.
    view full answer...
  • Timbren Rear Suspension Enhancement System Compatible with 2020 Ford F-350 Super Duty
    For your 2020 Ford F-350 Super Duty the compatible set of Timbrens are the Timbren Suspension Enhancement System # TFR350SDJ, and these will work with either a two-wheel drive or four-wheel drive truck, and can even be used on a dually. These are going to do a fantastic job of helping keep your truck level when it has a load on it, whether that's something in the bed or when you're towing. The Timbrens are extremely popular not only because of how effective they are, but how easy they...
    view full answer...
  • Does Timbren Kit # TFR350SDJ Fit 2017 Ford F-350
    The dimensions of the Timbren kit part # TFR350SDJ you referenced are 8-1/2 inches wide by 10-1/2 inches tall by 6 inch diameter. This is a confirmed fit for your 2017 Ford F-350 FX4 and does not require you to use any type of spacers.
    view full answer...
  • Does Timbren Suspension Enhancement Fit 2022 Ford F-350 Tremor
    Yep, it sure does; the Timbren suspension enhancement you asked about is a fit for your 2022 Ford F-350 Tremor. The correct part number is the following: - Timbren Suspension Enhancement System # TFR350SDJ The Timbren # TFR350SDJ are a really smart choice for optimizing the suspension of your F-350 because when you are towing or even just have a heavy load in your truck bed, the Timbrens are going to take the brunt of that weight instead of your leaf springs, which helps level and stabilize...
    view full answer...
  • Timbren Suspension Enhancement Recommendation for 2019 Ford F-350
    For your 2019 Ford F-350 the Timbren kit you need is the part # TFR350SDJ. This will help support the rear suspension of your truck when you are towing your fifth wheel trailer. I really like the Timbren kits over the air bag style kits as they are much easier to install and never require you to maintain air pressure or worry about air leaks. Also, since these kits install to the bottom of the vehicle frame they don't interfere with fifth wheel rails.
    view full answer...
  • Recommended Timbren SES for 2020 Ford F-350
    If you're carrying heavy payloads, the Timbren Suspension Enhancement System - Rear Axle # TFR350SDJ are the perfect solution and are a confirmed fit on the 2020 Ford F-350. The great thing about these Timbren SES Springs is that they only engage when the truck is loaded, so they won't effect your unloaded ride quality. The # TFR350SDJ will help lessen the strain on your stock suspension system, and because they work independently they'll help with off-center loads in the truck bed and...
    view full answer...
  • Timbren Suspension Enhancement Kit that Fits 2022 Ford F-350
    Yes we do have a Timbren kit that fits your 2022 Ford F-350 with the Timbren part # TFR350SDJ. This can provide an additional 8,600 lbs of suspension support. I attached an install video for you to check out as well.
    view full answer...
  • Is Timbren Rear Suspension For 2022 Ford F-350 Compatible With TorkLift StableLoad
    Yes, the Timbren Suspension Enhancement System # TFR350SDJ that fits your 2022 Ford F-350 is compatible with the TorkLift StableLoad. The two install completely separately so there won't be any interference between the StableLoad and the # TFR350SDJ.
    view full answer...
  • Recommended Suspension Enhancement For 2023 Ford F-350 Super Duty
    Big trucks like your 2023 Ford F-350 Super Duty often need some suspension help, and what I recommend are definitely Timbrens, with the correct part number for your '23 F-350 being the following: - Timbren Suspension Enhancement System # TFR350SDJ I highly recommend the Timbrens # TFR350SDJ because they provide a multitude of benefits to your truck; what they'll do is counteract both sag and body roll while also helping level your truck and stabilizing it to combat sway. The way they...
    view full answer...
  • 2020 Ford F-350 Super Duty With 4 Wheel Drive and Rear Sag Timbren Recommendation
    I recommend the Timbren Suspension Enhancement System - Rear Axle part # TFR350SDJ for the 2020 Ford F-350 Super Duty with 4 wheel drive. The Timbrens will do a wonderful job of keeping the load level and fixing the rear sag. They also act a shock absorber to absorb the bumps in the rode to create a more comfortable ride. I have attached a video for your reference.
    view full answer...
  • Purpose of Shims that Come with Timbren Suspension Enhancement System # TFR350SDJ
    The U-shaped shims of the Timbren Suspension Enhancement System # TFR350SDJ are designed to help provide a flat mounting surface for the bracket and help stabilize it from left to right. If there's any way you can get the dealer to track them down or replace them you really do want to use them.
    view full answer...
  • Recommended Timbren Suspension Enhancement System for 2021 Ford F-350 Super Duty
    For your 2021 Ford F-350 Super Duty I recommend the Timbren Suspension Enhancement System - Rear Axle # TFR350SDJ. These have an 8,600 lb capacity and help with vehicle sag while increasing stability. The springs work independently so they help compensate for off-center loads and reduce body roll as well as absorb shock from bumps in the road. Since you carry heavy loads with frequency the ride quality is less of a concern when unloaded. Regardless, the Timbren system still have an inch...
    view full answer...
  • Why Would Timbren On One Side of Truck be Compressed and Other Not at All
    The unloaded picture of your Timbren setup installed on your truck is concerning. Does the truck seem to sit level from left to right? Was it ever in an accident by chance? Are any of the suspension components worn out? You really shouldn't see that much compression on one side of the truck with that much gap on the other side unless something with the truck is bad.
    view full answer...
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  • Best Rear Timbren System for 2020 Ford F-350 for Towing Camper
    For the rear axle of your 2020 Ford F-350 the Timbren Suspension Enhancement System # TFR350SDJ will work perfectly. These jounce-style springs feature a robust 8,600 pound weight capacity but they won't reduce your ride quality in the truck. Since you tow frequently and typically have a bed full of supplies when not, these will be your best option for maintaining constant support, reducing rear sag, and taking some stress of the rear suspension for a longer lifespan on the truck. The...
    view full answer...
  • Recommended Timbren Suspension Enhancement for a 2022 Ford F-350
    Yes, we do have a set of Timbrens for your 2022 Ford F-350. They are the Timbren Suspension Enhancement System item # TFR350SDJ. These springs have an 8,600 lbs capacity, are compatible with an in bed hitch, and work with both the 2WD and 4WD models. I really like the Timbrens because they do a great job of keeping your truck level when it has a load on it. Whether you're hauling something in the bed or when you're towing a trailer the Timbrens will keep your rear end from sagging. The...
    view full answer...
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  • Do Timbren Suspension Enhancement Fit 2022 Ford F-350
    They sure do! I have verified for you that the following Timbren system does fit your 2022 Ford F-350 Super Duty, both the long bed and short bed, and both 2WD and 4WD: - Timbren Suspension Enhancement System # TFR350SDJ The Timbren Suspension Enhancement # TFR350SDJ are a really nice choice for your F-350 because because they will help improve your truck's handling and performance when you are towing or have a heavy load in your truck bed. With that added weight at the rear of your truck,...
    view full answer...
  • Will Timbren Suspension Enchancement Work With My Already Installed Rear Sway Bar
    When it comes to installing your Timbren Suspension System # TFR350SDJ on your 2022 Ford F-350 Super Duty, per the manufacturer you can install them with your rear sway bar already being attached, and there will be no problem. I have attached a install video link below.
    view full answer...
  • Will the Timbrens for a 2021 Ford F-350 Work With a 10K Trailer
    The weight capacity of the Timbren Suspension Enhancement System like part # TFR350SDJ for a 2021 Ford F-350 only applies to payload which consists of both tongue and pin weight. In others words, the capacity of the springs only needs to exceed the current payload of the vehicle which is any cargo you have in the truck bed and the tongue/pin weight of the trailer. It does not need to be rated for the entire gross weight of the trailer. These springs are an excellent maintenance option for...
    view full answer...
  • Is Timbren Fit the Same Between 2017 and 2021 Ford F-350
    The Timbren fits for a 2017 and 2021 Ford F-350 are the same with the part # TFR350SDJ. So what you have now would fit without needing a spacer.
    view full answer...

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Info for this part was:

Employee Leah B
Edited by:
Leah B
Employee Mike L
Expert Research:
Mike L
Employee Jameson C
Expert Research:
Jameson C
Employee Jacob T
Video Edited:
Jacob T
Employee Chris R
Video Edited:
Chris R
Employee Cole B
Installed by:
Cole B
Employee Mary K
Updated by:
Mary K
Employee Wilson B
Updated by:
Wilson B
Employee Carrie F
Updated by:
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Employee Bethann B
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Employee Jonathan Y
Video by:
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Employee Robert C
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