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  1. Vehicle Suspension
  2. RAS
  3. Towing/Load Leveling
  4. Leaf Springs and Helper Springs
  5. Helper Springs
  6. Rear Axle Suspension Enhancement
THIS ITEM IS NOT A FIT FOR
1997 Spartan EXP
etrailer Installation
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RAS

RoadActive Suspension Custom Leaf Spring Enhancement Kit

Part Number: RAS3614-T
In Stock
$539.00
Vehicle Suspension
Not Confirmed to Fit

1997 Spartan EXP

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etrailer Installation
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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 RAS3614-T can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (544)
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RAS Vehicle Suspension - RAS3614-T

Highlights

  • Custom Fit for Your Vehicle: Mounts to existing attachment points
  • 2,000-lb Load Support: Keeps your ride level when towing or hauling for better control and comfort.
  • Stronger, Safer Handling: Cuts sway, body roll, and wheel hop so steering feels steady and predictable.
  • Instant Load Response: Coil tension springs adjust as weight changes to stop sag before it starts.
  • Zero Maintenance Needed: Bolt-on kit works automatically—no air lines, drilling, or adjustments required.
  • Protects Suspension Life: Reduces strain on leaf springs, shocks, and tires for longer-lasting components.
Made in USA

Features to know about

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

Towing a trailer or hauling a heavy load can make the rear end sag and throw off your steering feel. This RoadActive Suspension Custom Leaf Spring Enhancement Kit adds up to 2,000 lbs of support to your rear suspension, converting factory leaf springs into a mechanically active system that keeps your ride level front to back. It strengthens your existing springs so they don’t flatten under weight, helping maintain traction, braking control, and proper headlight aim on the road.

Before-and-after comparison of a vehicle showing level ride height achieved with RoadActive Suspension installed under heavy load.

Cut Out Sway and Body Roll: Active Coil Tension Springs

When the back end starts to shift through curves or crosswinds, stability is everything. The variable-rated coil tension springs in this kit automatically adjust to your load, tightening up when weight increases and easing off when you’re empty. That active response reduces sway and body roll before they start, keeping your vehicle steady through corners and when a semi passes by on the highway.

Close-up of RoadActive Suspension tension spring showing variable-rated coil that supports leaf springs under load.

Eliminate Axle Wrap and Wheel Hop: Mechanically Active Design

Heavy loads can twist factory leaf springs enough to cause axle wrap or wheel hop that shakes the whole truck. This kit’s mechanically active design stops those problems at the source by absorbing load forces before they can build up. With the springs stabilized, you get smoother acceleration, surer braking traction, and fewer jolts when pulling out or climbing grades.

Illustration showing RoadActive Suspension preventing axle wrap and wheel hop by stabilizing vehicle leaf springs under heavy load.

Install Once, Drive Without Worry: Bolt-On, Maintenance-Free Setup

This custom kit comes fully assembled and bolts directly onto your existing leaf springs—no drilling, cutting, or welding required. Once installed, it’s completely maintenance-free and doesn’t need adjustments or air pressure checks. The epoxy e-coated alloy steel components and corrosion-resistant brackets (salt spray rated over 800 hours) hold up in all conditions, giving you lasting support without extra upkeep.

Installed view of RoadActive Suspension kit bolted onto vehicle rear leaf spring assembly showing proper hardware placement.

Close-up of RoadActive Suspension steel construction featuring epoxy e-coated finish and corrosion-resistant brackets.

Specs

Weight and Capacity

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

Warranty

  • Warranty: 5-Year warranty
  • Money-back guarantee: 30-Day money-back guarantee

Diagram showing RoadActive Suspension leaf spring enhancement kit installed on a rear axle, highlighting how the helper springs attach to factory leaf springs.

Close-up view of adjusting RoadActive Suspension coil tension spring using spacer gauge to set proper preload during installation.

3614-T RAS Custom Active Suspension System for OEM Leaf Springs - Rear Axle

Installation Details RAS3614-T Installation instructions

This Product Fits The Following Vehicles




Customer Satisfaction Score:

Ratings & Reviews

4.7

544 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 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:

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:

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:

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:

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:

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’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 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:

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:

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:

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:

Fantastic! Completely changed the way the truck tows. Kinda rides rougher unloaded, but not too bad.



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:

These made such a difference in the ride of my pick up while pulling my enclosed trailer. Let’s squat more stability.



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:

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:

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:

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



by:

I have Nissan 2500 van that I have converted for traveling. Its gross weight is 9000 lbs, and with all that is in it everyday it weighs around 7000 lbs. It has enough weight it sags. I occasionally pull a trailer, which makes the sag even worse.
I install the RAS, and it added about 1 1/2 inches to the truck height. I haven't pulled with it yet, but around town it rides great. Maybe, a very slight stiffening of the suspension, but nothing like what Timbren does to a truck.

These things were terrible to install. The instructions said there wasn't much clearance on this vehicle, so take apart the unit and put the spring hooks on before lifting the vehicle. I thought I was going to have to unbolt the springs. Using a jack in the right place allowed me to finally getting them into place. It did require much frustration, and some choice language before I finally got them installed.

I'm still looking forward to towing with them to see if the sag problem is fixed. I do recommend these. Again on a Nissan van they are a b*tch to install.



by:

Product quality, very well made

However,
installation not nearly as easy as listed on etrailer.com - they show a video of instal and steps that are really simple. However, when i got the kit and directions for my Nissan NV van, now it required dropping the leaf springs and installing while the vehicle was completely suspended. This is not that easy on a 3500 because those are some heavy strong springs. Plus it showed needing to adjust the springs with the suspension unloaded which is much harder to do yourself than if the vehicle weight was on the axle on a set of stands.



by:

2019 Nissan NV 2500 Cargo van owners please read!
Etrailer sent the wrong parts the first time, but they took care of it right away. Their customer service is great and this review should not reflect upon them.

The RAS seemed like a good solution to level the vehicle and reduce body roll, so I ordered them and installed. With the RAS at 40% and recalibrated at 40% after a test drive, it seems to do nothing. It does help if the van is totally empty, but who drives around an empty cargo van? I was at about 1/2 of the max payload and it still sagged in the back. I can’t speak for other applications, but this is not a good fit for Nissan NV. You have to remove a leaf spring bolt on this application while installing so it will hook between the spring and shackles.
I wound up taking the van to a reputable spring shop and had the leafs built up. It only cost me $100 more than the RAS, and now it drives like it should.

Mike L. profile picture
Etrailer Expert

Mike L.

7/25/2019

I spoke with my Roadmaster representative, and he explained that with this product, it is important to remember that it is designed to strengthen the existing leaf springs not resist and keep the vehicle perfectly level at all times. Anybody installing the kit should expect a little bit of give in rear leaf springs initially, then engage even more proportionate to and to counteract shifts in weight and uneven road surfaces, otherwise you’d expect a harsh ride to due lack of flexion in the leaf springs. Generally, if the vehicle is squatting up to 3-4 inches at the wheel well before installing the Roadmaster you should expect our kit to stay near level with somewhere between ¼’’ – 1’’ of give after installation. Beyond that, our kit will still help but from a load leveling standpoint it simply won’t be as noticeably effective. The vast majority of customers in the market for some sort of suspension enhancement product like this fall into this category. For the extremely heavy haulers & towers on the higher end of the spectrum that don’t want to purchase a bigger truck, they will usually tell them to go with an air bag set up.


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See what our Experts say about this RAS Vehicle Suspension

  • Recommended Suspension Enhancement For 2020 Nissan NV 2500
    I have another suspension enhancement option for you, but at this time there is not a Firestore or Air Lift Air Helper Spring Kit that is confirmed to fit your 2020 Nissan NV 2500. While you are correct that the 5.6l V8 engine is the same engine used in the Nissan Titan, the suspension is different between the two. For your NV 2500 I recommend the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS3614-T as it offers 2000lbs of support for your suspension, but also due to it...
    view full answer...
  • Suspension Enhancement Options For 2020 Nissan NV 2500
    Seems like you're needing some suspension enhancement! I recommend using the RoadActive kit # RAS3614-T. This will help your suspension from 0 to 100% travel. It's also adjustable to get the right amount of support. If that's not enough, get some helper springs # SSR-210-47 in the rear, these will only engage when your vehicle sags enough to hit the bump stops. If you're only looking to help the last half of your suspension travel and not hinder your smooth ride when you're not hauling,...
    view full answer...
  • Is There An Air Bag And Compressor Available For A 2017 Nissan NV 2500
    Though I may have another option, I checked with Firestone and Air Lift and, unfortunately, neither currently make a kit that will fit a 2017 Nissan NV 2500. With that being said, the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS3614-T is a highly recommended product. These do a very good job of helping with squat issues as well body roll and sway. The install is pretty quick and easy, and as long as you can jack your vehicle up by the frame, it is also pretty easy to...
    view full answer...
  • Best Suspension Enhancement System for a 2012 Nissan NV 2500
    The best rear end suspension enhancement system we offer for a 2012 Nissan NV 2500 is the RoadActive Suspension Custom Leaf Spring Enhancement Kit part # RAS3614-T. This is a pre-load system so it starts working right away and it can be adjusted so you can always get the best mix between support and comfort for your exact load. It's also very easy to install and requires no modifications. It's made here in the USA as well. The other options available for this vehicle are rubber jounce spring...
    view full answer...
  • Suspension Enhancement Recommendation for 2012 Nissan NV 3500
    The best suspension enhancement kit for your 2012 Nissan NV 3500 is going to be the RoadActive Suspension kit part # RAS3614-T once you get your suspension replaced. This will give you the best support, stability, and unlike other enhancement options it improves your ride quality.
    view full answer...


Info for this part was:

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 Manda E
Updated by:
Manda E

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