Get the best of both worlds with this authentic RAS® Heavy Duty RoadActive Suspension kit -- the only solution that strengthens leaf springs by up to 50% while providing a more smooth, controlled ride at all times.
Unlike other suspension upgrades that need constant adjustments & maintenance or negatively impact unloaded ride, RAS® greatly reduces squat, excessive bounce and body roll-- without hassle or sacrificing comfort .
This 3-in-1 system offers the benefits of a helper spring, sway bar, and traction bar at the fraction of the cost of other upgrades. With a quick 1-hour installation and zero maintenance, it's the simplest most effective way to reduce squat and improve your truck's towing/hauling performance.
FAQs (squat reduction, ride quality, how it works)
How does RAS® work?
RAS uses a variable-rate tension coil spring that attaches directly to your rear leaf springs. It works like a muscle, progressively engaging as load or force is applied. This keeps the leaf springs in an upright bowed position to prevent sag, improve stability, and enhance bounce isolation.
How much does RAS reduce squat?
Most applications see a 2–3" reduction in rear squat. The exact amount will depend on multiple factors such as vehicle size, load size, load placement, leaf spring condition, and the tension setting of the RAS.
Will RAS affect unloaded ride?
Expect same-as or better-than-stock unloaded ride with less bounce and more control.
Can I install it myself?
Yes—in as little as 45 minutes with jack stands and hand tools. No drilling, no airlines.
Why not airbags or helper springs?
Airbags add complexity and maintenance. Other helper springs fix sag only, can negatively impact ride quality, and don’t deliver the same combination of benefits. RAS is 3-in-1: controls squat, reduces sway, and improves traction.
🚚 1–2 Day In-Network Ground Shipping FREE
Transit estimates shown. Actual delivery times may vary.
*If your truck does have a factory top overload, it must be removed in order to install RAS and will provide slightly better than factory suspension strength.
RoadActive Suspension provides a 30 day money back guarantee, from date of purchase. However should the kit be returned, it must be re packed in the original packaging with all components included. On orders with free shipping (where shipping was paid for by RoadActive Suspension), refunds will reflect the invoiced amount, minus that shipping cost billed to us by our shipping provider. In addition, the customer will be responsible for the return freight charges.
It works with your suspension — not against it.
Each kit is tailored to your specific vehicle
RoadActive Suspension is uniquely assembled for your model and typically ships within 1-2 business days! RoadActive Suspension is the only suspension upgrade on the market that adds strength to your rear suspension, provides same as or better than stock unloaded ride quality and doesn’t require readjustments or maintenance.
Each RAS kit comes fully assembled out of the box and ready for installation. Follow your application guide that is in the box and you will be ready to test your RoadActive Suspension after an installation as simple as 45 minutes! If you are not satisfied with your RoadActive suspension we offer a money back guarantee.
Reduce Rear Squat & Bounce
Improve Stability
Improve Roadhandling & Stability
Make RVing Safer
Reduce Axle Wrap
No Readjustments or Maintenance
We already know what you're going to ask.
No, installing RoadActive Suspension (or any other rear suspension helper) does not automatically void the factory warranty. The Magnuson Moss Act states that it is illegal for a vehicle manufactuer or dealership to void a warranty just because a part has been installed. The manufacturer or dealership may only void the warranty if they are able to prove the aftermarket part caused or contributed damage to the vehicle. Even then, warranty to the impacted component(s) is the only portion of the warranty that may be voided. In this case, all other parts of the vehicle remain under warranty.
RAS uses a variable-rate tension coil spring that attaches directly to your rear leaf springs. It works like a muscle, progressively engaging as load or force is applied. This keeps the leaf springs in an upright bowed position to prevent sag, improve stability, and enhance bounce isolation.
Most applications see a 2–3" reduction in rear squat. The exact amount will depend on multiple factors such as vehicle size, load size, load placement, leaf spring condition, and the tension setting of the RAS.
Expect same-as or better-than-stock unloaded ride with less bounce and more control.
Yes — in as little as 45–60 minutes with jack stands and hand tools. No drilling, no air lines, no maintenance.
Airbags add complexity, cost, and ongoing maintenance. Other helper springs only address sag and can compromise ride comfort.RAS is 3-in-1:it controls squat, reduces sway, and improves traction — all with zero maintenance.
Customer Reviews
Overall rating: 4.7 / 5 from 186 reviews.
Best upgrade for our 2016 F250, we are a roofing company, We tow thousands of pounds of roofing material weekly. Our driving experience now feels comfortable and safe. Squatting and sway it's now a thing of the past...
Owen Romero
OD ROOFING
My company has a collective 43 trailers in total, ranging is size and weight, the smallest being only 950lbs, the largest being a 43foot tandem axle gooseneck weighing roughly 7000lbs dry. The most used is my 16foot, 4000lbs equipment trailer. I haul everything from equipment, to cars. Not only to I tow alot, the bed of the truck is loaded down with a toolbox that has chains/binders, fluids, tools, etc, shovels, cooler, and a removable 55 gallon fuel cell. Along with the work trailers, i have a smaller, yet surprisingly heavy travel trailer (8000lbs). When I built the truck I wanted to still keep functionality for towing, but with the lift, came softer suspension, and the truck started to sag. I heard about the RAS system, and tried it out, and the results are amazing. It eliminated body roll, smoothed out the trucks overall ride, both loaded and unloaded, and greatly improved the amount of squat with trailers. The system isn't airbags, so don't purchase thinking its going to do what airbags do, its not designed to level out the load, but rather to help reduce squat and improve overall ride quality, for a fraction of the price, and very easy install, that requires zero maintenance, and that's exactly what it does. I've put the system thru its paces, and I have been very impressed. Hell, I just bought 6 more for my company vehicles. Along with an amazing product, the customer service is just as awesome, Nolan had been great to deal with. if you're on the fence about purchasing, just do it, its worth every penny.
Absolutely the best. Will never go back to air bags. When not loaded don’t even notice unless I get hard on the throttle and then I noticed no wheel hop, just hook up and go.
For towing really stabilized the ride. Less bouncy and more solid. Even the wife commented how much better the ride was.
I use my 2020 Ford F250 Super Duty to pull a skid steer trailer and a travel trailer, both with 1800# of tongue weight. This weight, plus some cargo in the truck bed caused significant rear suspension sag. The RAS HD kit solved the problem. No more rear sag or headlights shining up into the sky.
After pulling tractor before RAS and now squat is gone. Researched air and springs and completely glad I chose RAS. Install was easy. I would put this on any other truck hauling equipment. Thanks for great product
I have a 2022 F250 king ranch diesel. I was a bit skeptical but really want to get rid of that cement freeway bounce. Although it’s still a truck, but this kit is amazing. It almost rides like a Cadillac Escalade now. Towed my 24 foot trailer with a classic car inside and I almost forgot it was behind me. A truly satisfied customer.
2011 F250 with 6.7 Powerstroke. Truck wobbled on large loads before RAS. Put on the HD kit reducing squat/sag by 2” and then pulled 11,000lbs over a 26-hour drive. It was a drastic, positive change and I felt much more control over my load on rural areas and mountains where highways have dips and curves.
Installed on 2024 F250 4x4. It did raise the back end up about 1- 1/4" with white disc setting. Took about 45 minutes to install, adjust and test. Latched onto my Jayco Eagle 30CRT and both sit perfectly level. Drives better while towing. Going across road to bridge transitions much smoother. I absolutely didn't make a mistake with this purchase.
Pulling a 41 foot fifth wheel and the RAS has improved an already capable vehicle. By far the easiest suspension upgrade I’ve ever installed and it out performs anything I’ve experienced. The best part is unloaded characteristics and handling are not negatively impacted like air bags and springs swaps. The hitch weight squat is improved and the rough road porpoising is virtually eliminated. I’m so impressed with the quality, and ride improvement. Honestly I don’t know why the manufacturers of tow capable trucks don’t incorporate this technology in their vehicles. If you’re towing a light trailer you will see some improvement and if you’re towing anything over 10,000 pounds you should have this system. Sway, squat and porpoising are the challenges of towing heavy and large trailers. Especially if your load weighs change regularly. I wanted to get some
miles on the truck before reviewing and the more I drive the happier I am with the RAS.
Got my kit for the notoriously poor-riding 24’ Super Duty F250 FX4.
Zack wasn’t the main issue as much as it was just daily driving when there wasn’t a load. The additional springs up top and load stoppers they put in place on the stock suspension makes it ride like a 1 ton truck. It’s the worst.
I was utterly shocked by how big a difference in pain and it only took an hour to put it on all set and done. Wasn’t expecting even close to this kind of improvement $500 products..
Couldn’t be more pleased!!
Not only a quality product but the customer service, for even stupid questions, was totally amazing. Had the product in my hands 3 days after ordering. Thank you for all you do! I’ll load pictures later!
I installed RAS 3611-SLHD kit on my 2026 F250 Lariat and I am very pleased with the results. It was easy to install and fit perfectly. The hitch on the back of my truck is now 1.5" higher than before, with no load. Now, when hooked to my 28 ft camper there is 1.25" less squat at the hitch, and the front truck raises only 1/2 inch. The truck rides smoother loaded & unloaded, and with less sway. The only complaint is the long socket head bolts used to attach the RAS under the leaf springs. This bolt takes a large hex socket, which I did not have, and I don't think most backyard mechanics do either. I would suggest the manufacturer replace this with a standard bolt so that common wrenches can be used.
So I decided to go ahead and Install the RAS-HD kit on our 2016 F250 to better stabilize and reduce squat.On my second time pulling since the install we had the chance to experience some crosswinds while towing our 37ft fifth wheel and all I can say is what a difference these springs have made in the overall ride quality. The truck is noticeably more stable all together and holds its own a lot better than prior to installing these. The install was absolutely one of the easiest upgrades I have ever done to the truck and we have had bags before and just got tired of all the leaks and constant adjusting so this go round I wanted a set it and forget it system and man I am impressed.
Helped a ton to smooth out the bumpy ride when I'm all loaded up and to cut down on the squat a little bit. Going to be ordering another kit for my other truck. 2016 F250 with the 2011-2016 F250 HD Kit
2024 Ford Superduty
Order S-22973
Part: 3611-SLHD
We recommended this kit for a new truck buyer that buys their fleet from us. The truck would squat with a payload. I had to remove the roadactive and install airbag suspension for the customer that we normally do for their trucks. I also had to absorb the difference in labor expense and refund the customer for the parts price difference to make it right.
My F250 Superduty XLT powerstroke turbo diesel had no problem pulling my 40' 5th wheel RV, but it squat more than I care to see....
I purchased the road active suspension and I was greatly pleased with it.
Easy to install and made a visible difference in the ride hight and the handling on rough roads.
Two thumbs up 👍 👍
2010 ford f-250 w/45’7” toy hauler fully loaded for boondocking water, fuel, 4seater side be side handled great and lessened the sag by 2” great product for the money. 4 hour install because of taking off the upper overload spring. Worked great and as advertised. Quality built and made in the USA
Kit is very detailed and easy to install shipping was fast if I didn't have to remove the upper leaf springs I could have had it install in less than a hour my truck drive and handle so much better I like it thanks RAS
Installed the RAS HD kit on my 2022 FordF250, did not cause a hard-harsh ride empty. Actually enhanced the stock ride. While towing my 2025 travel trailer with 850# tongue weight and 8,600 # there is no sag and helped with sway. I had airbags that drove me crazy with constant adjustment towing and empty. I can now enjoy towing and empty travel without worry! Great kit , easy to install!
2019 F250. Truck has a leveling kit in front with 35/12.50/20. RAS returned positive rake and helped reduce squat with load. The ride is much better now with RAS. Smoother on bumpy roads and less body roll around curves.
I have a 2021 F250 with an 8’ utility bed on it which is heavy and causing the truck to sag and with the enclosed trailer connected it was even worse, truck handled very poorly, after installing the Roadactive suspension, the truck only went down 2” with the trailer on and it handles like a dream, very happy with the results and well worth the money.
Thanks
The stock suspension sucks on a 2023 ford F250. Putting this kit on changed the way it pulls. I no longer have that squat with my light trailer and handles my gooseneck way better. 10/10.
I have a 2017 F250 Crew cab. Presented as having a trailering package. But we have always had 4 - 6 inches of rear droop when we hooked up our goose neck horse trailer. I got the F250 Heavy weight option and installed them at the max spacing. Awesome results. The ride felt immediately stiffer and less bounce on our bridge extension road, 24 miles. Hooking it up to our horse trailer, we had at max 2 inches of droop when then hooked up. Awesome results, as predicted.
I opted to try this system with my sagging 2008 Ford F250 Hardly Davidson Crew Cab and it got me an inch + increase and less sag and bouncing and also rides just a hair better unloaded.
I have a 2002 Ford F250 2wd that have also “converted” to a dually (can’t afford one so might as well make due with what ya got) and I was looking for something that would help take some wait but I did not want bags and having to deal with that bank drainer system so I found this system one day and decided why not. Install was simple for an older truck. Instructions a little vague on one thing that I had to reach out to RAS for but they were able to respond quickly and answer my question. Loaded it handles perfectly like it’s designed to do and it definitely will take the weight. Unloaded it helps make my truck ride a little smoother. I’ll have to play with the adjustment a little more i would prefer to be a little stiffer but overall I like it and recommend this system over the expensive alternative.
2023 F250. The install was as easy as it looked (hardest part was remounting the tires). Love the ride quality unloaded and when loaded I now sit level. Feels Great.
My 2005 F-350 came with a front leveling kit installed on it. As a result, it didn't take much weight to get the back end squatting a little. It also felt a bit unstable in high-speed curves between the added height and the lack of a rear sway bar. RAS sounded like a great option to improve the performance of my truck's suspension, and after installing it it has been as advertised. I started with setting the RAS on the 2mm spacer, and was surprised to see it raise the rear of my truck roughly 2". Driving it I felt a noticeable increase in the firmness of the rear end, but without harshness. Cornering stability was dramatically improved. I hooked a trailer with 900lb tongue weight and the truck still sat slightly higher in the rear than at the front. I decided I wanted to try dialing back the RAS slightly, but didn't want to go all the way down to the 1mm spacer. I found a washer that was 1.5mm, set the RAS to that, and now the truck feels very nicely dialed in. The empty ride is nice and still has greatly improved cornering stability. The unloaded height is about 1.5" higher than without RAS. With my travel trailer, the truck and trailer both sit nice and level, and there is a noticeable reduction in porpoising while towing. Overall, I am very satisfied with my RAS kit.
Select your vehicle details to see only matching kits.
Shipping
Fast & Free Shipping
Is Faster Than Ever
With our expanded RAS® warehouse network, most orders reach you in 1–2 business days. Transit times depend on inventory levels and carrier performance.
UPS Ground transit estimates from our network (AK/HI and outlying areas may vary).
How It Works
Orders placed by 3 PM local time for popular part numbers can ship the same or next business day from the nearest in-network location. Delivery estimates are based on UPS Ground service.
Eligible States
Our multi-warehouse setup enables 1–2 day transit to ~98% of the continental U.S.. Alaska, Hawaii, Montana, North Dakota, South Dakota, and some remote regions typically see 3–5 business days.
Eligible Part Numbers
Currently eligible for in-network 1–2 day transit:
3611-YHD
3611-HD
4611-HD
5611-TZHD
4611-TDHD
3611-BHD
36113-THD
3611-SLHD
4614-SAT
4614-SAT
4611
4617-T
3611-Y
Note: Availability varies by SKU and location. Most orders ship same/next business day, but lead times and carrier estimates are not guaranteed.
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RoadActive Suspension, Inc. provides the original retail consumer our Warranty that each new RoadActive Suspension, Inc. product shall be free from defects of material and workmanship, as set forth in this limited Warranty.
Length of Coverage
Except as provided below, RoadActive Suspension, Inc. offers the following duration:
1. RoadActive Suspension, Inc. kits and their components are warrantied in the United States and Canada against defects in workmanship and materials for five (5) years following installation on the vehicle for which the kit is purchased.
2. The Warranty is terminated immediately when you transfer ownership of the vehicle to a second party, or it is used for a purpose not intended, regardless of your consent and/or if the product is installed on a second vehicle, regardless of when the second installation takes place. Because of these provisions, the Warranty is not transferable.
Authorized Sellers Only
Warranty coverage applies only to products purchased directly from RoadActive Suspension, Inc. or from an authorized RAS dealer or retailer. Purchases made from unauthorized resellers or third-party sellers (including online marketplaces) may not qualify for warranty coverage.
Obligations
RoadActive Suspension, Inc. shall be limited to replacing or repairing, free of charge, any part or parts that reasonably appear to us upon inspection to have been defective in material and/or workmanship. You will be responsible for the cost of transportation charges and any charges in connection with reinstallation of the defective parts.
Exclusions and Limitations
The limited Warranty does not cover and RoadActive Suspension, Inc. will not be held responsible for any costs or injury you sustain by reason of the following:
1. Parts and labor necessary for removal, reinstallation, vehicle modification, or any vehicle repair, service, or replacement, and repair of defective parts other than RoadActive Suspension, Inc. defective parts, regardless of cause.
2. Any repair or replacement made necessary by any accident, breakdown, or failure of bolts, nuts, washers, or any other parts used to install the products, whether or not by RoadActive Suspension, Inc.
3. Unreasonable use, failure to install or maintain the product properly, modification of the product, or failure attributed to a defect in the vehicle, towing, fire, theft, environmental condition, or negligence, accidental or intentional damage or destruction.
4. Incidental or consequential damages, including but not limited to compensation for loss of use of the product or vehicle, inconvenience, lost profit, or any other direct or indirect loss.
Individual Components Policy
For liability and safety reasons, RoadActive Suspension, Inc. does not sell or distribute individual components of any RAS kit separately. Each RoadActive Suspension kit is designed, tested, and warrantied as a complete system. Replacing or modifying any component independently—including threaded rods, brackets, or hardware—may affect system integrity and void all warranty coverage. Replacement components are only available through approved warranty claims or complete kit purchases.
Non-Warranty Replacement Policy
In cases where damage occurs due to installation error, misuse, or other non-warranty causes, replacement components are available only through the purchase of a new complete RoadActive Suspension kit. Individual components are not sold separately for safety and compliance reasons.
Warranty Void Conditions
This warranty will be considered void if any part of the RoadActive Suspension kit is altered, modified, or installed incorrectly, or if the product is used in any way that differs from its intended purpose. Warranty coverage also becomes void if non-RAS components are substituted or used in conjunction with the system in a way that may affect performance or safety.
Third-Party Modifications
RoadActive Suspension, Inc. is not responsible for any issues or failures that result from the use of aftermarket components, vehicle modifications, or non-standard installations. The RAS system is designed to function only with stock vehicle configurations unless otherwise specified in writing by RoadActive Suspension, Inc.
Inspection Recommendation
As the installation and removal are not covered by this Warranty, we recommend that you inspect the installation of the RoadActive Suspension, Inc. kit to ensure that the product was installed safely and presents, beyond any reasonable doubt, no danger to any other part(s) of the vehicle such as brake lines, gas tank and lines, sewer lines, electrical wiring, or the chassis.
How to Obtain Service
To obtain warranty replacement parts or repair, RoadActive Suspension, Inc. must first be contacted by letter or telephone, providing your name, make, model, and year of vehicle, and evidence of date of installation. Written or verbal approval will be given to you by an authorized RoadActive Suspension, Inc. employee, and you must then return the part to be replaced or repaired—at our option—freight paid, to our warehouse. The replacement part will be shipped within fifteen (15) days following our receipt of the original part.
Be sure to obtain our approval before returning products to our warehouse. They will not be accepted until approval is obtained.
Disclaimer
The above Warranty is the only warranty extended to you by RoadActive Suspension, Inc.
ALL OTHER OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE HEREBY EXCLUDED.
Governing Law
This Limited Warranty shall be governed by and construed in accordance with the laws of the State of North Carolina, without regard to its conflict of law principles. Any disputes arising from this Warranty shall be brought exclusively in the state or federal courts located in Mecklenburg County, North Carolina.
