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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. Tried and true since 1998.
Watch Installation VideoFAQs (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.
*Does not fit 2022-2024 models with single leaf spring
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: 4.8 / 5 from 584 reviews.
2024 GMC Sierra 1500 4x4 SLT. I purchased the HD suspension for my truck because I have different trailers with multiple amounts of weights. I am exceptionally impressed with the ride on our maiden voyage to pick up our newest trailer which will haul our motorcycles for trips all over. So far we have pulled 2 different trailers and the suspension performed flawlessly. Thank you for a great product.
A piece of cake to install just need metric wrenches and socket along with Allen key. As they say about 45 minutes to set up . I set mine first to 20% setting to drive around with small loads like stone and soil . So far great going to move my camper out from storage as soon as weather breaks and see what drop is on pickup. It was almost 3” at first . It is great that I can still adjust up to 40% if I choose. I own a 2021 GMC evaluation 1500 pickup and this will make a great addition to equipment I already have on it. These RAS helpers are so much better then my past truck with air shocks. Thanks Shawn for being so versed in your product you where a great help in my decision .
2018 GMC sierra crew cab 5’9” bed! What an improvement over the air bags! My ride empty improved by a mile! Towing is another story! This has got to be the best after market suspension part I’ve ever used! We just took a long trip with at least 1000 lbs of gear in the bed and towed our 21’ bass boat! No sway no pogo sticking it’s like a different truck! Thank you for developing an amazing product! Every truck I own from this day forward will have the RAS system on it!
I put $3000.00 worth of air bags on my other truck and let me tell you after installing the RAS system on this truck what a waste of money the air bags are. This HD RAS system on my 2021 Chevy High Country 1500 Duramax stills gives me an amazing ride loaded or unloaded. I installed the HD system in about 45 mins. I set it up for the max load capacity this did lift the back of my truck about 1 inch. It still has an amazing ride and no body roll when driving. With a 9000lb bumper pull trailer it sits at stock height and rides extremely well. I have also noticed an increase in fuel mileage I believe this is because the front of the truck is not so high when pulling now. This RAS system is the best money i have spent on the truck. The installation is extremely simple! If you can change a tire you can install this system. I also want to say their customer support and tech support is absolutely fantastic. If you are on the fence about trying this product JUST DO IT!
2021 Chevy 1500 RST 3.0L diesel. Easy install,
about a 1/2 hour per side. Raised the back of the truck by about 3/4" on lower setting. Truck handles very nice and a much more stable feel. Had Sumo springs prior to the RAS. They were very harsh when you hit a bump unloaded and offered nothing as far as overall vehicle stability. RAS is super smooth.
I have a 2020 Chevrolet Silverado. I put my RAS on my truck today. Hooked up my RV and headed 2 hrs to the camp ground. I was so amazed with the handling of my truck. Very smooth ride. Very little bounce. I should have bought RAS before.
Great customer service and fast delivery. Easy installation, and works flawlessly. Was debating between airbags and this and chose RAS! Highly recommend it!!!
Installed the 4611-HD RAS kit on my '19 Chevy Silverado in less than an hour, and that includes taking the tires off and on. I'm so stoked with the results! Towing my camper was almost scary before install, now it's 100 times better. Virtually no sway. Very little bounce. Pulls far smoother than before. The truck gained 2" at the hitch without a trailer hooked. Coupled with my weight distribution hitch, my truck and camper ride completely level. I wish I could give more stars, I've been telling everyone that'll listen about this kit!
I was skeptical that these would do much. I was blown away that it didn’t change my ride with empty weight. Definitely less squat from the load of my travel trailer. Trailer seems to tow a lot better.
16 GMC Sierra 1500.
Install was SUPER easy!
Installed on 2017 gmc 1500 and it made an immediate impact. Load feels much more stable and truck is not squatting nearly as much.
Comfort of a 1500 with handling like a 2500.
One of the best investments you can make for your truck. Eliminates squat 100% without a harsh ride and easy to switch from truck to truck. Will not have a 1/2 ton truck without this suspension system.
I received the items very quickly as promised. The packaging was done very well and everything arrived in perfect shape. The install was incredibly easy. One bolt installation and turn one nut to adjust.
I bought the RAS to replace the SUMO springs on my 2020 Silverado 1500. I feel like the RAS works with the suspension of the truck to make it work better, stronger and still allow movement. The SUMO felt like the truck became a teeter totter over the back axle when attached to my travel trailer.
I have always added rear sway bars to my pick up trucks for handling purposes. These work just as good if not better plus all the other options that they give you along with just wanting a sway bar type handling. They are similar to traction bars I’ve had on a drag truck for actual rap, and the truck is simply so much more comfortable to drive going over any type of bumps or anything. I am absolutely thrilled with this product, and I even haven’t had the chance to tell anything with it. And I expect nothing less than being as thrilled with that, as I am with everything else. If you are just looking for a better handling, they are worth every penny. As I can only imagine how much better it makes towing with this design. It is also great as I have not lifted the truck yet, but there is no way that it will interfere with a lift kit this way, as opposed to installing a sway bar. It is absolutely the newest way to go as far as strengthening and stiffening up the rear of your truck. They are worth every dollar for an addition to your truck.
My husband and I bought a 32' Forest River Cherokee Greywolf travel trailer. I wasn't sure, at first, if my Chevy 1500 truck could handle a trailer that big. After reading many, many reviews and talking with several "knowledgeable" people we decided to go ahead and get the trailer. Worst case scenario, I get a bigger truck 😁. From the RV dealership to the storage lot about 25 miles away the truck pulled the empty trailer with no problem. After loading the trailer with all our gear we took it out camping (glamping) for 3 days and only about 15 miles from the storage place. The truck still pulled the trailer with no problem BUT the trailer bounced alot over bumps and bridges and made me very uncomfortable driving it. Someone at the campsite recommended RAS so I started checking it out and lots of reading and You Tube videos later I ordered my RAS kit. My husband and I installed it in about an hour (we are both 70 years old) and took the trailer on a 4 day trip about 40 miles away. I AM BLOWN AWAY!!! The bounce (porpoising) is hardly there anymore and the ride was very comfortable. We used the black spacer (50%) when installing the RAS. Even without towing the trailer I noticed a difference driving the truck, almost like it hugs the road better. I couldn't be happier with my RAS and highly recommend it!
Just got a new tow vehicle 2026 Silverado 1500 RST Z71. Picked up the RAS 5611-TZHD to help with the rear squat while towing. Just got home from a 500 mile trip towing my camper and it handled like a dream. I love worry free towing! The install was super easy and videos from others were excellent. I installed the pair in about 45 minutes. I highly recommend it to anyone on the fence.
The truck I installed these on, is an 06 GMC Sierra 1500. The truck only has 100k on it for mileage and is in very nice shape, however it's a 20 year old truck, and the leafs were getting kind of weak. I added the RAS to help with that, as well as to help when pulling my trailer with tractor. As you can see in the pictures, the ride height is very noticable between the two pictures with the trailer hooked up. The height did increase by about 1.5 inches unloaded. But the ride is most definitely worth it. Night and day difference when pulling, almost eliminated the common "porpoising" with pulling a bumper pull trailer. And much to my surprise, the unloaded ride is amazing, you almost don't even notice most bumps when the rear of the truck passes over them!!! This is set on the 20% setting.
2018 GMC Sierra 1500
I tow a 20 foot boat. Any divot or bump in the road causes the truck to bounce dramatically and would bottom out on the bumpers. Before RAS I installed Bilstien 5100 rear shocks which helped with the rebound, it still bounce dramatically but was a smoother ride. With the RAS 4611-HD it has improved the bounce where it’s even a lot more comfortable, the truck doesn’t bottom out on the bumpers, the truck doesn’t squat nearly what it did, and it feels a lot more planted to the ground. The RAS system did raise the rear end up 1.5inches which I’m am not mad about at all. I’m so glad I went with the 4611-HD vs the standard strength.
2025 chevy 1500 ZR2 3.0. Installation is pretty straight forward. It adds an inch or 2 in height when unloaded to the back end but with my 7200 pound trailer on it sits perfectly level. Really doesn't affect ride when unloaded, if anything feels more planted. It did exactly what I wanted for an amazingly fair price. I really couldn't be happier!
Just got back from a 250 mile trip and they made it so much more comfortable!! May need to make some minor adjustments, but I am very pleased with the results.
What a wonderful piece of engineering. After upgrading front and rear suspension, I still felt that the rear end of my 2008 Sierra was still too soft for the tandem axle trailer I tow frequently. I also lost the rake I had with stock suspension. This RAS kit was the right way to go, I gained 1.25" of rear lift and the ride is exponentially better than before. Now the truck doesn't squat with the trailer and I have the rake I was looking for, without changing any of the rear suspension components. 10/10, extremely satisfied
Installed on my 23 Silverado 1500 ZR2, and so for it is doing everything it claims. Easy installation, eliminated the sag from the rooftop tent on the truck and seems to have helped the sway. Have not put many miles on the truck yet and no off roading, so still a little early for review but all good so far
Put on my 2015 silverado 1500 with rocky ridge addition. HD kit, big improvement in over all handling with or without trailer. Did not effect ride when unloaded, too my surprise. Even made it better. Pull 16 enclosed trailer daily. Even out the small squat that I had. Highly recommend
I recently installed the RAS system on my 2024 Silverado 1500 LTZ with max-tow. Installation was fairly easy. The truck now sits 3/4” higher in the rear and it didn’t degrade unloaded ride quality. I recently towed a large flatbed, squat was minimal and it handled the load well. I originally considered adding air bags but the RAS system is so easy. You set it once and leave it.
I wish I had known about these when I bought my truck six years ago. The are ALOT Better than those flat small leaf spring helpers, and are by far easier to adjust. (look really good on the flat spring)
Had to add a 2” lift to front. Made 1/2” lower on front than back. Should be pretty close to level when pulling my trailer. Very happy with the purchase.
Drive a 17 chevy 1500 with a commercial cap and ladder rack. Did up graded shocks and bump stops but this was only thing to help handling and minimize pogoing on the highway
I have a 2016 GMC SLT 4x4 with a 2.5" front spacer lift and RAS in back. I tow a steel frame enclosed 24' car hauler and with 4 guys and a race car, the tounge stays level and the ride is safer and smoother with RAS installed. A jack, two heavy duty jack stands, and its a 45 min job. The first side is learning, the other side goes on quickly. Tightening them is simple using the shims. Watch a few installation videos prior. Also helps overall with porpoising, or bouncing, seems to dampen that out better too.
Installed the HD kit on my 2023 GMC Sierra AT4 overland build. I recently got a new camper topper and with all my gear I had just a little bit of sag going on. I wanted to get that little bit of rake back. With the HD kit turned on the lowest setting (using white spacer disk), I have gained back my 3/4-1” back in rake as the camper sits on the truck. Now with all my overlanding gear I will sit perfectly level. Just getting the sag out was my only goal of buying this set…… however…..the first 4 miles of driving down the road I felt an immediate and dramatic change in how my truck now handles. It is so much more planted in the rear. What amazed me was going over bridge divets where normally the axle would hop around,. That is completely gone!!!! The only way I can explain it is that it feels like the chassis is now all independent suspension. I’m just completely shocked in how it rides now. Also this truck is not a pavement princess and it sees trails and off-roading every time it goes out. So I will be putting this kit to the test as the miles roll on. I’m still left in shock being that something so simple in design shows me such a dramatic change in in comfort and ride. Wish I would have found this product sooner. Glad I didn’t go with an add a leaf beating my head off the ceiling on washboard forest roads 🤘
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.
Ready to Upgrade Your Truck?
Get RoadActive Suspension delivered fast — straight to your door.
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.
