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  1. Vehicle Suspension
  2. RAS
  3. Leaf Springs and Helper Springs
  4. Towing/Load Leveling
  5. Rear Axle Suspension Enhancement
  6. Standard Duty
THIS ITEM IS NOT A FIT FOR
2016 Mazda 6
etrailer Installation
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RAS

RoadActive Suspension Custom Leaf Spring Enhancement Kit

Part Number: RAS3620
In Stock
$539.00
Vehicle Suspension
Not Confirmed to Fit

2016 Mazda 6

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etrailer Installation
We'll connect you with nearby partnered installers who know this exact setup.
2,000-lb Capacity. Convert your vehicle's leaf springs into a mechanically active suspension system. RAS adjusts to your load to level your ride. The system also increases stability, handling, and control by improving traction and reducing sway. Great Prices for the best vehicle suspension from RAS. RoadActive Suspension Custom Leaf Spring Enhancement Kit part number RAS3620 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (542)
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RAS Vehicle Suspension - RAS3620

Highlights

  • Custom Fit for Your Vehicle: Mounts to existing attachment points
  • 2,000-lb Load Support: Levels your ride when towing or hauling so steering and braking stay steady.
  • Instant Stability Under Load: Coiled springs engage right away to cut sway, squat, and bounce.
  • Smoother Daily Driving: Springs disengage when unloaded so ride comfort stays the same.
  • No Ongoing Maintenance: Once bolted on, there’s no air pressure to check or adjustments to make.
  • Protects Suspension Life: Reduces axle wrap and wheel hop to ease wear on springs, shocks, and tires.
Made in USA

Features to know about

Stay Level and Confident Under Load: 2,000-lb Rear Suspension Support

Heavy trailers, campers, or bed loads can cause the rear of your vehicle to sag and the front to lift, throwing off handling and traction. The RoadActive Suspension Custom Leaf Spring Enhancement Kit adds up to 2,000 lbs of support by converting your factory leaf springs into a mechanically active suspension system. The variable-rated coil tension springs automatically adjust to your load, keeping your ride level and maintaining steady traction while braking and accelerating.

Vehicle comparison showing RoadActive Suspension kit keeping the truck level under load to improve stability and traction.

Stop Sway, Bounce, and Body Roll Before They Start

When you hit curves, crosswinds, or winding roads with a heavy load, sway and body roll can make driving stressful. This system strengthens your rear leaf springs to stabilize your load and reduce sway before it even begins. The active design improves stability and handling whether you’re towing a trailer or running empty, which helps your vehicle feel more planted on corners and through highway gusts.

Put an End to Axle Wrap and Wheel Hop

Under load, leaf springs can twist enough to cause axle wrap and wheel hop that jolt the rear tires off the road. Each RAS unit uses its coil tension spring to absorb those forces before they twist the spring pack. That means smoother takeoffs, better grip under acceleration, and less strain on your leaf springs, shocks, shackles, and tires over time.

Diagram showing how RoadActive Suspension prevents axle wrap and wheel hop by stabilizing leaf springs under heavy load.

Install It Once and Forget It: Fully Assembled, Maintenance-Free Design

You don’t need extra air lines or compressors to make this system work. The kit comes fully assembled with all hardware included for an easy bolt-on install—no drilling, welding, or cutting required. Once set up, it needs no adjustments or monitoring. The epoxy e-coated steel construction and corrosion-resistant brackets have a salt spray rating of more than 800 hours for lasting durability in tough weather and road conditions.

Close-up of corrosion-resistant steel construction on RoadActive Suspension kit showing e-coated springs and heavy-duty brackets.

Specs

Weight and Capacity

  • Weight capacity: 2,000 lbs
  • RoadActive Suspension will not increase your vehicle's weight-carrying capacity

Warranty

  • 5-Year warranty
  • 30-Day money-back guarantee

3620 RAS Custom Active Suspension System for OEM Leaf Springs - Rear Axle

Installation Details RAS3620 Installation instructions

This Product Fits The Following Vehicles




Customer Satisfaction Score:

Ratings & Reviews

4.7

542 reviews
Review sort icon
2,000-lb Capacity. Convert your vehicle's leaf springs into a mechanically active suspension system. RAS adjusts to your load to level your ride. The system also increases stability, handling, and control by improving traction and reducing sway.

by:

I installed the Road Active suspension standard duty kit on my 2017 Tundra. I was hoping for a smoother ride with and without a load and I was not disappointed. I don’t do heavy hauling, just a center console boat that weighs about 3000 pounds with trailer. My truck definitely has a smoother ride. It is especially noticeable on rough spots like bridge crossings, etc. I set the springs somewhere in between the light and heavy settings. I used a quarter as a spacer. It raised the rear of my truck one inch. I definitely recommend the Road Active suspension and etrailer is the best place to buy it.



by:

Overall, very happy with the product. GMC didn't have any way to improve the truck from squatting when I hooked up my trailer. This kit didn't stop the squatting but significantly reduced the bounce on bad dips in roads, bridge/road transitions and bad railroad crossings.



by:

Hands down the engineering behind the product was well executed and would recommend it to anyone who's travels involve pulling any type of trailer. You will feel a much smoother ride even when not pulling a trailer at all.



by:

I received this kit in a very timely manner always do from etrailer have some issues with the instructions that come from roadmaster not a trailer the bump stop spacer didn’t say that you need to use the original bolt from the bump stop so it slowed me down greatly on the install however I took it out on a quick run without a load I do feel that this has made the unloaded ride smoother tomorrow I’ll be taking the trailer out for a bit and we’ll see how it works there and I’ll update this rating.



by:

Made all the difference in the world! Also, easy to install. Yes, the ride is stiffer, but when I'm dragging the 10K of weight in the trailer, it's worth it.



by:

I found this items cheaper on another site but etrailer match and then beat the price.
Item installed super easy, more work jacking up the truck and taking the tires off. Can be installed with out removing tires just make it easier to get it in. The item did lift the back of my truck 1 inch. See Pics.



by:

I Have had this suspension on multiple trucks and i love it . It takes the sway out of the truck when entering a exit ramp and taking sharp turns with a trailer or without, also reduces wheel hop and increases payload in the bed of the truck.I would recommend for all trucks pulling trailers.



by:

Easy install 2011 Tacoma crewcab long bed. Helped with sag when towing microlite travel trailer. Keeps the rear end raised in the rear a little when unloaded, but I like that look. Only complaint and its nothing big when truck is unhooked and empty when i get out I can hear alittle noise from RAS. Sort of like a bedspring coil. Night pic is with RAS installed daylight pic is with out installed



by:

I love the product since i have a 2021 toyota tacoma crew cab long bed with a campertop a robber mat and a jack thats around 450 pounds that a have at all times my truck was sittind low a lilbit plus it was swagging on the road i have summo spring to help my suspention but it was not enoght so i did my research but this was my better option i just installed it yerterday july-8-2021 and went for a ride where i ussually drive everyday and WOW now my truck rides very smood plus it lift my tryck 1 inch on the back now my tryck seats level it took me about 2 hrs but i did right i just follow the intructions and done i love the product the only thing that im concern is that the left side underneat the springleaft there is a breik line that is too close to the roadmaster suspention i hope that with the time dont hit that line because if it does thats the line for the breiks and i will be in trouble replacing it other wise evreything works great i recomend it 100% thanks guys i will buy it again?????best $500 that i spend on my truck



by:

I have a 2020 Silverado 1500 6 cyl Duramax with the Diesel Off Road package (3.73 diff). Travel trailer loaded is probably about 6,000 lb. I took several measurements during and after the spring kit installation. All measurements increased about an inch including the stock suspension with trailer and equalizer bars and with the spring kit installed at 1 mm spacing. A one inch improvement overall. I took the truck on a short drive and didn't notice any difference in ride (wasn't stiffer) which is what I wanted. Good to know that I can adjust the springs to the 2 mm spacing if I want to increase the suspension assist. Going camping next week and looking forward to see how it improves handling and porpoising.



by:

The bed of the truck measured 37.5" with a tool box weighing 200 lbs. The truck felt weighed down with passengers weighing 600lbs. Total weight 800lbs with a tank full of gas. After the install the truck rides smoother and certainly " like new". The stopping distance and acceleration distance have shortened drastically. I'm planning on loading up the bed and the Roadmaster Active Suspension RAS4611. My wife even drive it and she could feel the difference. "It drives like a muscle car." Buy it. Install time at a reputable mechanic shop was a 30 min. Install. I received them today at 1 pm and got it installed at 3:00 pm and finished the install at 3:30pm. It's an investment worth the price over traditional air bag system. Mechanic installed this on 2011 Nissan Titan SV.



by:

Balances ability to tow my 1800 squaredrop Hiker camper with 350 tongue weight as well as roof top tent on Leer 180 camper topper. Better handles load and side to side tipping on '21 Ranger. Keeps sage to a minimum.



by:

I have put these on every pickup that I have owned and not only does it assist with heavy loads, my tires have gone past 80,000 miles before needing replacement. All Chevy Duramax 2500's and 3500's!!



by:

Did not fit my 1995 F-150. ETrailer was very helpful in an effort to make any adjustments needed. We all decided that they were a "no go" for installation. Return was made easy. I have bought several other pieces of gear since. Thank Etrailer.



by:

i installed these on my 2001 ford f-250 4x4 and this is a huge upgrade whether your towing or empty.truck rides and handles better than it ever has. easy straight forward installation. you will need a t-55 for the front bolt and a 12mm ratchet wrench for the adjustable bolt that tightens the spring and a couple of 22mm and a 19mm wrench or crescent wrenches for the jam nuts. i took the weight off of the leaf springs for easy adjustment of the coil spring and used the thinner of the two disc that came with the kit and it raised the rear of the truck up exactly 1 inch empty without a trailer connected. if you use the thicker disc it will raise it more.



by:

I haven't hooked up my camper yet but set the springs up with the white wafer and it raised my truck 1 1/2 inches which is the amount it dropped after I put on a fiberglass topper. The ride is just a bit stiffer but a lot less body roll I noticed. Not impressed with the 25 Silverado suspension compared to my previous 2017 truck. If the squat is still there after I hook up the camper, there is plenty of adjustment left.



by:

Great product, helps with sway and when the truck has additional weight it progressively compensates. I would add this to any vehicle with leaf springs.



by:

Helps immensely, 12x6 inclosed trailer from NY to Florida and back up to NJ no problems



by:

Easy install when I rotated tires. Forgot to measure height difference, but it did raise a bit. I like the adjustability and not having to remove springs and shackles to add a leaf. Will be towing the camper with improved support.



by:

I don’t think they are really made for the old PU. 1997 k1500 8 ft bed with a 750 lbs camper tong weight I think I had to put to much pressure on the Kurt stabilizer chains to get level. It looked like the newer truck reviews on YouTube were great thanks Dingler.



by:

2023 F150. Install was fairly easy. Set at 25%. Ride unloaded a bit stiffer, but handling much better. Lifted rear of truck about an inch. Towing 7500 lb camper down NYS thruway which is crowded with much unforgiving bumps and pot holes the ride was more manageable. The 25+ mph cross winds did make for quite a bit of sway still, not as bad as before adding the RAS. Still felt passing trucks trying to suck me in, not as bad as before.
I plan on cranking the RAS to 40% on next camping trip and hopefully give the RAS 5 stars.



by:

I’ve bought a lot of products from etrailer and as always everyone I dealt with is professional and knowledgeable of the numerous products they sale. I used every resource they offer to help me decide what type of suspension upgrade I was going to use to improve the haul and tow ability of my 2017 diesel chevy Colorado 4x4 crew cab short bed. I chose the RAS system from Roadmaster. I also called them and ask some very detailed questions about using my OEM shackle instead of replacing with the plates in the kit and was told that was fine and that others had also. I got professional and knowledgeable info that helped make my decision. The product is exactly as promoted and every review out there on the internet about how good or unchanged the unloaded ride is after installing are true. My truck rides better now and it was already quieter and almost as smooth as my wife’s Cadillac. If your looking to improve the drive, tow and haul ability of your leaf spring vehicle, and I say vehicle instead of truck because I don’t know if they have them for other leaf spring vehicles, you are not going to find a better easier to install product that does that for your loaded or unloaded vehicle, IMHO. I will update in a year after next spring mulch haul. I don’t expect zero squat but hope to reduce and improve loaded steering performance. Took longer to jack up truck and remove tires than install kit.



by:

I purchased the RAS system 6 months ago to help with rear end sag & control while towing our 22 ft 4200lb camping trailer. It improved sag & helped handling even when not towing! I don't get the bounce when driving on bumpy uneven roads the wheels stay planted on the road. I recently purchased a 8000lb camping trailer & my 24 1500 Silverado handles it very well, I will adjust the RAS to the next step up for the extra weight when time permits.
The install took just over an hour with help from a friend & a car lift which is good since I'm 70 years old.
Great product!



by:

Just perfect to level the rear of my GMC 1500 Denali with the 29' Airstream (900 lb tongue wt). Preload is set at 1mm. I tried 2mm and it was overkill for this application. I was pleased with how easy the install was. I had to use a two jack hack to get the rear tires off since my 19" lift floor jack didn't quite have enough reach. You lower the differential after the tires are off so the rear axle is hanging free for the install. See photos



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See what our Experts say about this RAS Vehicle Suspension

  • Best Suspension Enhancement Recommendation for 2017 Sprinter RV
    Hey Dewey, the best suspension enhancement we have for the rear of your 2017 Mercedes Benz Sprinter 2500 would be the Roadactive Suspension Kit part # RAS3620. Of all of the kits we offer this is the one we get the best feedback on in terms of ride quality and improved handling. Unlike other options this also has the ability to adjust the amount of support you have too so you can really tailor it to your tastes. I can definitely relate to the "rolling earthquake" as I have a Chevy Tahoe...
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  • Improving Handling and Parked Stabilization of 2017 Winnebago View 24J
    The best solution for ride quality and stability for your 2017 Winnebago View 24J will be with a SumoSpring # SSA11MTKT installed. This gives better suspension support that translates the best into improved handing, comfort, and support. Scissor jacks like the part # TJSCHD-24 will do a great job supporting the RV when parked too. For a sewer hose storage container that will work with the above hose, I recommend the Valterra RV Sewer Hose Carrier part # A04-3460BK which has an inner...
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  • SuperSprings Rear Helper Springs on 2016 Mercedes Sprinter 2500 are Not Engaging
    Having that slight gap between the new SuperSprings # SSR-329-47 and the platform they make contact with is common not just with this brand but with others as well. It allows your suspension to compress some so as not to have too much of an effect on the unloaded ride quality. Since the springs are not engaging at the rear of your 2016 Mercedes Sprinter 2500 that means that the factory suspension is not compressed enough. And that means that the amount of weight you have in the van is...
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  • Rear Suspension Enhancement For a 2019 Mercedes-Benz Sprinter 2500 To Reduce Sway and Sag
    I have a couple options for you that are application specific for your 2019 Mercedes-Benz Sprinter 2500. These are the systems for the different types of drive and suspension types I recommend using. First the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS3620 fits 2wd vans that have a single blade rear leaf spring. Finally the SumoSprings Rebel Custom Helper Springs # SSR-327-40-2 fits 4wd vans.
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  • Best Rear Suspension Enhancement For 2016 Chevrolet Silverado 1500 W/ Truck Bed Camper and Trailer
    For your 2016 Chevrolet Silverado 1500 Z71 with a truck bed camper and towing a trailer I recommend going with the RoadActive Suspension Leaf Spring Enhancement Kit # RAS54FR. This kit will give you the best enhancement to your suspension as it not only gives you a 3000lb load leveling capacity, but also reduces sway and eliminates axle wrap give you a better loaded and unloaded ride. In comparison the Air Lift LoadLifter 5000 kit you currently have only helps with load leveling, but...
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  • Do Wheels of 2019 Mercedes Benz Sprinter Get Removed to Install RoadActive Suspension Kit
    When installing the RoadActive Suspension system kit part # RAS3620 on your 2019 Mercedes Sprinter 2500 you would need to remove the rear wheels after jacking the vehicle up off of the ground. You can have the heavier stuff installed as long as your jack is capable of lifting that additional weight when you go to install this.
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  • Will The RAS Kit Fit A 2023 Chevy 1500 Trail Boss With A 2" Factory Lift?
    The RAS kit will work on most lifted trucks, but it will completely depend on how exactly your 2024 Chevy 1500 Trail Boss was lifted. As long as the factory leaf spring has remained unchanged the RoadActive Suspension Custom Leaf Spring Enhancement Kit will still fit. The HD RAS kit for your truck is part # RAS54FR. Keep in mind that this kit will only fit trucks with steel leaf springs. It will not fit truck with the composite mono leaf springs.
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  • Best Suspension Enhancement for 2019 Mercedes Benz Sprinter 2500
    For what you are wanting from the ride of your 2019 Mercedes Sprinter 2500 the absolute best option for suspension enhancement is the RoadActive Suspension Kit part # RAS3620. This gives you additional support, less sway and body roll, and noticeably improved ride quality and handling whereas other options will make for a rougher ride quality. There's also no issues reported with chassis cracking with these kits. The support of this is also adjustable unlike the SumoSprings kit you mentioned. There...
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  • Suspension Enhancement that Fits 2011 Mercedes Benz Sprinter 2500
    We have suspension enhancement that fits your 2011 Mercedes Sprinter 2500 and will work great like with the RAS kit part # RAS3620 but there aren't any air bag kits that fit. I really like the RAS kits because they require zero maintenance, install easy, provide great support, and unlike other options improve ride quality and stability.
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  • Best Suspension Enhancement for 2018 Mercedes-Benz Sprinter 3500
    The best way to improve the suspension on your 2018 Mercedes-Benz Sprinter 3500 is with the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS3620 because it is an active system which works to continually reinforce your original leaf spring suspension. The force normally put on your van's current leaf springs, either when carrying cargo or when making a tight turn, gets transferred to the RAS Enhancement Kit, allowing your leaf springs to work normally. The RAS Enhancement...
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  • Does RoadActive Suspension Kit RAS3620 Fit 2017 Sprinter 2500
    Yes the RoadActive Suspension kit part # RAS3620 is a confirmed fit for your 2017 Mercedes Benz Sprinter 2500.
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Info for this part was:

Employee Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Mary K
Written by:
Mary K
Employee Wilson B
Updated by:
Wilson B
Employee Noah M
Updated by:
Noah M
Employee Carrie F
Updated by:
Carrie F

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