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Timbren Suspension Enhancement System - Severe Service - Rear Axle

Timbren Suspension Enhancement System - Severe Service - Rear Axle

Our Price: $398.07
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8,000-lb Capacity hollow rubber springs sit above the rear axle to help stabilize and level your vehicle. Provides a comfortable ride by absorbing road shock and improving stability. Ideal for trucks with slide-in campers or an in-bed salt spreader. Great Prices for the best vehicle suspension from Timbren. Timbren Suspension Enhancement System - Severe Service - Rear Axle part number TFRTT350F can be ordered online at or call 1-800-940-8924 for expert service.
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Timbren Vehicle Suspension

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

8,000-lb Capacity hollow rubber springs sit above the rear axle to help stabilize and level your vehicle. Provides a comfortable ride by absorbing road shock and improving stability. Ideal for trucks with slide-in campers or an in-bed salt spreader.


  • Improves suspension, handling, and safety
    • Ideal for trucks with slide-in campers or an in-bed salt spreader
  • 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
      • Increases stability - providing great performance while hauling heavy loads
      • Reduces vehicle sag
  • Works independently - side-to-side
    • Helps compensate for off-center loads
    • Reduces body roll when swerving and turning corners
  • Acts as shock absorbers, taking the brunt of bumps and rough roads
    • Extends the life of your vehicle's suspension


  • Includes 2 Aeon hollow rubber springs, vehicle-specific brackets and hardware for simple installation
    • Replaces axle bump stops on frame
    • No drilling required
  • Capacity: 8,000 lbs
    • Do not exceed the vehicle's weight-carrying capacity
  • Height of bracket sides: 3"
  • Spacer height: 1"
  • Spring length: 3-3/4"
  • Designed to work with a suspension system that is in good working order
  • Limited 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.

FRTT350F Timbren SES with Aeon Hollow Rubber Springs - Rear Axle - Severe Service

Item # TFRTT350F

Installation Details TFRTT350F Installation instructions

This Product Fits The Following Vehicles

Customer Satisfaction Score:

Customer Reviews

Timbren Suspension Enhancement System - Severe Service - Rear Axle - TFRTT350F

Average Customer Rating:  4.7 out of 5 stars   (5767 Customer Reviews)

8,000-lb Capacity hollow rubber springs sit above the rear axle to help stabilize and level your vehicle. Provides a comfortable ride by absorbing road shock and improving stability. Ideal for trucks with slide-in campers or an in-bed salt spreader.

2005 Ford F-350 Super Duty

Easy to install and great support from the manufacturer. These raised my rear by 2 inches, eliminated the sway at high speeds, and all but eliminated squeeky spring noise on my 2005 F-350 fully loaded with a truck camper.


The installation was not as easy as shown on the etrailer you tube vids.This was on a 2016 F 350.Do yourself a favor and just use a cutoff wheel or sawzall to remove the factory bump stops.After much cussing I finally got them installed and they do make a difference.

Volkswagen CC

A year ago, I added Timbrens to my '09 F350 to help carry a '09 Lance 915 camper. Since my truck is a CC LB diesel model, the truck payload and loaded weight of my camper are similar. I found the Timbrens a cost effective way to limit the suspension sag and improve truck/camper sway. When unloaded, I rarely notice the Timbrens as they are ~1.5" away from the spring pack stop and only engage on large bumps. I also like the maintenance free aspect of Timbrens. To further enhance the loaded ride, I am replacing the thin factory contact pads on my overload springs with larger ones. I found that adding the Timbrens limited suspension travel such that it prevented adequate overload spring engagement with the factory pads. The replacement overload pads from Torklift and Supersprings are 3" (too much IMO as they contact the overload spring nearly all the time making for a rough ride). I am cutting down a set of Superstops to ~1.5 - 2" for the right amount of overload spring contact and Timbren engagement but still maintaining unloaded ride quality.


Easy enough to take on and off. I put them on when hauling my 5th wheel and take them off when we aren't traveling. Great product!

2005 Ford F-350 Super Duty

Have not installed the bump stop system yet but came home to a large post office crate on the porch and in it was the Timbren box all broken in pieces. Luckily all the parts were there especially the the bolt and washers bag!


They were so easy to assemble and install on my 2015 Ford F350 SD I was able to do it in my driveway in about 45 minutes.

Ford F-350 Super Duty

I have a f350 super duty and pull a 44' 5th wheel rv, the weight in the bed runs around 2tons. The way the weight is carried now with timbrens is awesome,the bed drops about one inch. I have 1" between the timbren supports and the frame. Would have a bit smoother ride when not pulling if there was another 1". No complaints though about that.


The system made the empty ride way too rough. I only left it on the truck for 2 weeks and then took it off however after being installed it was not returnable.
I ended up going with Roadmaster active suspension and I'm very happy with that choice.

2016 Ford F-350 Super Duty

I cannot review this product yet because I have not installed it. The package arrived missing one of the main necessary parts, so now I am waiting for etrailer to ship a replacement. I need this installed ASAP, so I can complete a job. It was a disappointment and inconvenience when things did not arrive as planned. Also, etrailer keeps referencing my orders to Courtney, which is not my name, or whose name was used in the order.

Etrailer Expert

Katrina B.


We hate to see items missing, when it comes to the products that we sell. I have sent this information over to our customer service team for them to contact you.


They worked great until one of the rubber coils fell off. The housing remained but the rubber coil fell off!!! Not worth the price. I would never buy this again.

2015 Ford F-250 Super Duty

The TIMBREN rear suspension parts that I installed on my 2015 F-250 Super Duty fit and function like they said and are nice because they stay on the vehicle for ever and there is no maintenance. If you are carrying a lightweight Slide-In Camper or one that is well within your vehicle's GVW,PAYLOAD AND RAWR, this product will more than be adequate.

Nissan Leaf

I've ordered from etrailer previously, and this is my third set of Timbrens, as I was very pleased with the performance of the previous sets, and the fact that they don't engage until the truck is loaded, and don't require any adjustment or have any moving parts. The installation is easy on a new truck, as everything is clean and the bump stump fasteners that need to be removed aren't corroded. I upgraded to the heavier set of Timbren's this time, and needed to jack the truck in order to fit the spring and spacer between the Timbren mount (on the frame rail) and the axle stop. If I had elected to omit the spacer, I would've been able to install the spring w/o the spacer. However, I wanted to reduce sag when trailering, and am willing to sacrifice some ride comfort. The Timbrens are engaged now w/o a load in the truck (only an auxiliary fuel tank), and the rear of the truck now sits 3/4" higher than on the OEM spring pack (incl. factory overload leaf springs). I have not had a chance to run loaded and unloaded, but am hopeful that the unloaded/no trailer ride will not be too harsh.


The Timbrens are great, I do have to say they ride rough if you put the spacer in with them, but if you take out that rear spacer and run the bushing and the metal, it rides just as how it rode from factory. I pulled a loaded up trailer and the truck doesnt squat at all. If you tow a big trailer on the regular like myself (landscaping industry) these are a must. Even ordered them for my other work trucks too.


Helps with limiting rear suspension saging when towing 5th wheel RV.

2009 Ford F-350 Super Duty

Cannot give a review at this time. When I received it, the first thing I noticed was the box was beat up pretty bad and was wrapped with a lot of tape. When I opened the box, there was only 1 bracket and no bolts or instructions. I contacted etrailer and they are sending me the rest of my parts. I hope they arrive quickly. etrailer should have inspected the box when they saw how beat up it was

2013 Ford F-350 Super Duty

Very easy install, reduced the trucks squat. The ride loaded is better, empty ride is slightly more bouncy. But im almost always loaded up with a truck camper

2015 Ford F-350 Super Duty

Arrived on time. Installation went well. Pleased with how well the Timbrens leveled my camper. Still very good ride when camper not on my 2015 Ford F350 Super Duty dually. Very satisfied with this product.


I've had theses installed for about a year and are great. No ride difference when not towing a 33 foot trailer. With the trailer it only dropped about 2 inches with no ride difference when towing. Easy to install. I reconend this.


Mounted on 2010 F-250 4 x 4 truck. As soon as you open the box, you realize that this is a heavy duty bracket and bump stop replacement. Much better quality than OEM. I did not use the spacers because I wanted a normal ride until there was a load was on the truck.


Easy to install and have performed nice ly


Nothing to leak or tear up

2009 Ford F-250 and F-350 Super Duty

Great product easy to put on. We haven't towed our camper yet so I can't really say how it well it works.



Still working great.

2016 Dodge Ram Pickup

It arrived in 3 days and only took one hour to install. This is my second set. Put the first set on a 2009 Dodge Ram 1500 & this set went on a 2016 Ford F-250 Super Duty Diesel....very satisfied,


Products arrived as scheduled, installed very easily. Works better than anticipated



I have sold that truck and bought a new one. One of the first things that I did was install a set on the rear. It now 45ft fithwheel trailer. One of the best towing or hauling upgrades available

2014 Ford F-350 Super Duty

Fast shipping and always great service. There install videos they do are always helpful. Highly recommend purchasing products from them!

Show More Reviews

See what our Experts say about this Timbren Vehicle Suspension

  • Which Timbren Springs Are Recommended for a 2008 Ford F-250 with In-Bed Camper
    For your 2008 Ford F-250, I recommend using the Timbren Rear Suspension Enhancement System part # TFRTT350F as this kit has a 8,000 lb weight capacity and is specifically designed for trucks with an in-bed camper. These springs will provide the most amount of support for your situation. In addition to added support, the springs will also work to reduce body roll and increase stability. I have attached a review video of the above system for you as well.
    view full answer...
  • Which Timbren Helper Spring Set Should I Get For My 2012 Ford F-350 4X4
    I recommend # TFRTT350F for your 2012 Ford F-350 4X4. It has an 8,000 pound weight capacity, which will support the load you have and help with the stability of the ride.
    view full answer...
  • Recommended Timbren Rear Suspension Enhancement System for a 2015 Ford F-250 with In-Bed Camper
    For your 2015 Ford F-250 Super Duty Diesel with in-bed camper, I recommend the heavy-duty Timbren Rear Suspension Enhancement System part # TFRTT350F. This system was designed by Timbren specifically for vehicle's with an in-bed camper. This system will most importantly reduce sag but will also work to prevent body roll and increase stability while turning. They are very easy to install and do not require any maintenance which is what makes them so popular. I have attached a review video...
    view full answer...
  • Timbren Rear Suspension Enhancement System Spring Fell Off 2008 Ford F-250
    This is extremely rare and I can only imagine this happening if the springs were incorrectly installed, or were in the wrong location, under an extremely heavy load, or possibly having the wrong system installed. Per the instructions, there should only be a gap between 1/2 to 1-1/2 inches when the vehicle is empty. That gap is eliminated when the vehicle has a load added. The Timbren system is designed to work with a suspension system that is in good working order.
    view full answer...
  • Solution for Reducing Harshness In Ride Quality of Timbren Kit TFTTT350F
    Remove the spacer between the jounce spring and the mounting bracket. That will give you more clearance so that the suspension can move a few inches before activating the Timbren.
    view full answer...
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  • How to Use Timbren Rear Suspension Kit # TFRTT350F in 2006 Ford F-250 with 2-Inch Suspension Lift
    Timbren offers 1-inch spacers # A25723-90AH00 that can be used when their rear axle suspension kits are to be installed in a lifted truck. You'll need 2 spacers per side in your application and to locally source 2-inch longer bolts. Please refer to the linked video that shows a suspension kit being installed in a lifted truck.
    view full answer...
  • Which Timbren Kit HD or Lighter Duty for 2016 Ford F-350 That Hauls Campers Frequently
    The difference in harshness between the Timbren kits part # TFR350SDF and # TFRTT350F would be very noticeable. Especially when unloaded. Your truck is already going to have a rough ride as that is the nature of 1 ton trucks but the 12k Timbren kit will make for a very harsh ride when unloaded. I really wouldn't recommend that unless the truck is going to be loaded to near it's max capacity most of the time it will be on the road. For what you are looking to do I would go with the lower...
    view full answer...
  • Best Timbren Suspension System For 2008 Ford F-350 For 5th Wheel & Truck Bed Camper
    That's a good question, and between the two systems, the best one for your 2008 Ford F-350 for support while you are towing your 5th wheel as well as when you using a truck camper is the 8,600 lb option: - Timbren Rear Suspension Enhancement System # TFR350SDF The 8,6000 lb capacity of the # TFR350SDF is more than enough for both the pin weight of your 5th wheel as well as your truck camper. More than that though, the reason they are the best is because they are double-convoluted, while...
    view full answer...
  • Recommended Suspension Enhancement for 2014 Ford F-350 Super Duty Hauling 16 ft Trailer
    There is a suspension enhancement solution that will work for your 2014 Ford F-350 but the Timbren # TFRTT350F is designed for use with service vehicles such as tow trucks and would not be the best option for you. Instead I highly recommend the Timbren Rear Suspension Enhancement System # TFR350SDF which have an 8,600 lb capacity and will give your truck the support it needs when hauling your water tank and pressure washer skid. This system will not require any drilling and works by becoming...
    view full answer...
  • Recommended Timbren Suspension For a 2012 Ford F-350 Converted Into Feed Truck
    Since you will be using the Timbrens on a 2012 Ford F-350 feed truck which will spend most of its time loaded you will want to use the Rear # TFRTT350F springs with the Front # TFF350SDC springs you found. The rear kit is their severe service kit which is designed to provide more stability on trucks which constantly carry very heavy loads. Do understand while this will greatly increase ride stability when loaded it will diminish ride quality when unloaded due to the stiffness of the springs.
    view full answer...
  • Differences Between Timbren Helper Springs TFR350SDF and TFRTT350F for a 2016 Ford F-350
    Timbren helper springs # TFR350SDF and # TFRTT350F both fit the 2016 Ford F-350. Kit # TFRTT350F is rated for 8,000 pounds but was designed for sever service vehicles such as tow trucks. Kit # TFR350SDF is rated higher at 8,600 pounds and fits regular consumer pickup models. The kits use different rubber springs and different upper brackets as well. I have linked the instructions for both for you to compare.
    view full answer...
  • Suspension Enhancement for a 2002 Ford F-350 4x4 with a 6 Inch Lift
    You could install the Timbren springs # TFRTT350F on a truck with a lift but they will not be effective because of the extra 6 inches of space. What I recommend are some SuperSprings, # SSA16, which fit around the leaf spring stack so the lift should not be a factor. I have included a link to the installation instructions for you.
    view full answer...
  • Will Air Bags Work On a 2013 Ford F-350 with Flat Bed
    I do have an option for you but for a constant load like the service body/flat bed has, we recommend the Timbren Rear Suspension Enhancement System part # TFRTT350F which is designed for this exact purpose. It's not adjustable like air bags but the adjustability really doesn't matter for constant loads and these are maintenance free so you don't ever have to worry about them. They will not only support the weight of the bed but also additional gear and trailers.
    view full answer...
  • Correct Timbrens for a 2001 Ford F-350 Cab and Chassis
    There are two Timbren Rear Suspension Enhancement Systems for a 2001 Ford F-350, part # TFR350SDF for standard models or part # TFRTT350F for service models. If you have a cab and chassis I recommend the latter as they will be better suited for this application.
    view full answer...
  • Which Weight Rating Timbren Rear Suspension Enhancement Should I use on my 2009 Ford F-250
    It depends on the loads you are putting in your 2009 Ford F-250. The Timbren Suspension Enhancement Systems for F-250 rear axle have the following capacities: 6,000 pounds for part # TFR250SDF and 12,000 pounds for part # TFRTT350F. If the total weight of what is in the bed of the truck and the tongue weight of any trailer used is less than 6,000 pounds, use part # TFR250SDF. If the combined weight of what is in the bed an any trailer tongue weight is more than 6,000 pounds, use part #...
    view full answer...
  • Recommended Timbren Suspension Enhancement System For 2016 Ford F-250
    The Timbren Rear Suspension Enhancement System I recommend is part # TFR250SDG, and is a confirmed fit for your 2016 F-250. This will help with the handling of the vehicle when under a heavy load such as when you are towing your fifth wheel. This system has an 8,600-lb capacity and They replace the bump stops and do not affect the empty ride of your truck. The Timbrens will not increase the load-carrying capacity of your truck. These are designed to work with a suspension system that is...
    view full answer...
  • Will Timbren Springs Fit On 2013 Ford F-250 Without The Raised Bump Stop Above The Axle Tube?
    Yes, you can still install the Timbren Springs # TFRTT350F on your 2013 Ford F-250 without the raised stop like you have seen in the images you found. I have included an image below which shows their other Kit # TFR250SDG for your F-250 on a truck without this device so the bump stop will be contacting the axle. Timbren recommends having 1" of clearance between their spring and your axle when unloaded. This will help to prevent the unloaded ride from being severely harsh. You may or may...
    view full answer...
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  • Which Timbren Springs Should I Use For A 2016 Ford F-250 Super Cab With 8,000 lb Jayco 5th Wheel
    For your 2016 Ford F-250 Super Duty, the Timbren Rear Suspension Enhancement System that is the best fit for your application is the # TFR250SDG. It has a 8,600 lb capacity that will suit your needs well. The Timbren springs compress as needed for support, and the heavier weight capacity the stiffer the spring. With these style of springs you don't want to over-do the capacity because it will give you a more rigid ride for your truck. When they aren't engaged with a loaded weight, you...
    view full answer...
  • Recommended Suspension Enhancement for 2013 Ford F250 with Service Body
    We have a Timbren Aeon Spring system that is specifically designed for service-body truck and has the high capacity necessary for such a vehicle, part # TFRTT350F. The springs will add extra support to your rear suspension, and will become progressively stiffer as more weight is added. A weight distribution system would work best for combating the squat you experience when towing, but the Timbren system will help somewhat. Since you tow infrequently and for short distances, you can probably...
    view full answer...
  • Selection of Timbren Rear Axle Suspension Kit for 2006 Ford F250 Crew Cab Short Bed 4WD
    The Timbren Rear Suspension Enhancement System # TFRTT350F is intended primarily for heavy-duty service vehicles but would work fine for your application. Both this kit and the lower-rated # TFR250SDF are confirmed fits for your 2006 Ford F-250 Crew Cab Short Bed 4WD. For your reference I have linked the instructions for both kits along with a video on the TFR250SDF. Please note that all suspension kits, including these Timbrens, are designed for use with vehicles whose suspension systems...
    view full answer...
  • Timbren Suspension Enhancement Recommendation for 2016 Ford F-250 Towing Fifth Wheel
    I would recommend the Timbren part # TFR250SDG which has the 8,600 lb capacity over the part # TFRTT350F as this kit is designed for severe duty vehicles like tow trucks. The ride quality would be rather harsh. I attached an install video for the # TFR250SDG for you to check out as well. This kit will provide you the support you need without being overly harsh.
    view full answer...
  • Timbren Suspension Enhancement Recommendation for a 2012 Ford F-250 Super Duty
    We carry the two different Timbren kits for your 2012 Ford F-250 Super Duty the part # TFR250SDG which is the lighter duty kit and the part # TFRTT350F which is the heavier duty kit. The lighter duty kit will provide 8,600 lbs of support and the heavier duty kit will provide 12,000 lbs of support. If you plan on maxing out your vehicle suspension then I would go with the heavier duty kit. If you aren't planning on using every last bit of the capacity then the lighter duty one will work...
    view full answer...
  • Timbren Suspension Enhancement Recommendation for a 2015 Ford F-250 Towing Fifth Wheel
    Timbrens would be a great option for you. These will provide you with suspension support when you need it and won't affect ride quality when you aren't towing. The kit you will want is the part # TFR250SDG which is the lighter duty of the two sets available for your truck. The higher rated part # TFRTT350F has a much stiffer rubber spring as it is designed for severe service vehicles only. I attached an install video for you to check out as well.
    view full answer...
  • Recommendation for Timbren Springs for 2011 Ford F250 Super Duty Towing a Pop-Up Camper
    If it were my truck, I would go with the # TFR250SDG. Timbren probably recommended the # TFRTT350F to just be extra cautious about the weight of the camper. The # TFR250SDG system will have no problem carrying the stated camper load weight rating. I've attached a video of it being installed on your vehicle for your convenience.
    view full answer...

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Info for this part was:

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