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  1. Vehicle Suspension
  2. RAS
  3. Leaf Springs
  4. Rear Axle Suspension Enhancement
  5. Standard Duty
Roadmaster Active Suspension Custom Leaf Spring Enhancement Kit

Roadmaster Active Suspension Custom Leaf Spring Enhancement Kit

Item # RAS4514-SAT
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Our Price: $499.00
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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. Lowest Prices for the best vehicle suspension from RAS. Roadmaster Active Suspension Custom Leaf Spring Enhancement Kit part number RAS4514-SAT can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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RAS Vehicle Suspension - RAS4514-SAT

  • Leaf Springs
  • Rear Axle Suspension Enhancement
  • RAS
  • Standard Duty

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.


Features:

  • Custom kit converts your vehicle's factory leaf springs into a mechanically active suspension system
    • Actively strengthens leaf springs for improved ride quality with or without a load
  • All-in-one suspension system improves stability, handling, and control
    • Eliminates axle wrap, wheel hop, and bottoming out
    • Reduces dangerous sway and body roll while cornering
    • Keeps your ride level when towing or hauling a heavy load
    • Improves traction while breaking and accelerating
  • Variable-rated coil tension springs automatically adjust to your vehicle's load
    • Activate immediately to support the extra weight
    • Disengage when unloaded, allowing your leaf springs to perform as intended
  • Customizable coil springs can be adjusted during installation to accommodate your towing or hauling needs
    • Independently adjustable for side-to-side leveling of off-center loads
  • Helps extend the life of leaf springs, shock absorbers, shackles, and even tires
  • Durable, epoxy e-coated steel construction
    • Corrosion-resistant brackets on the ends of each unit have a salt spray rating of more than 800 hours
  • Easy, bolt-on installation - no drilling, cutting, or welding required
    • Unit secures under the leaf spring and around the factory U-bolts
    • Fully assembled kit and hardware are included
  • Maintenance-free - adjustments and monitoring aren't needed once installed
  • Made in the USA


Specs:

  • Weight capacity: 2,000 lbs
    • Roadmaster Active Suspension will not increase your vehicle's weight-carrying capacity
  • 5-Year warranty
  • 30-Day money-back guarantee


All-In-One Suspension System

When towing or hauling a heavy load, you may encounter a number of problems that can make your driving experience difficult or dangerous, such as sway, body roll, or bottoming out. When your vehicle is weighted down, your factory leaf springs can't counteract these problems to the extent that they are supposed to. The weight will overpower the leaf springs and cause them to twist or flatten out. When that happens, they cannot support, level, or stabilize your vehicle effectively. Additionally, because your factory leaf springs are passive, they won't begin to tackle problems such as sway until those problems have already started.


Diagram of RAS Installed

Roadmaster Active Suspension (RAS) kits enhance those passive leaf springs by converting them into a mechanically active, all-in-one suspension system. RAS kits have variable-rated coil tension springs that automatically adjust to your heavy load. Other suspension systems only solve a few problems and usually at the expense of other improvements your factory leaf springs may need. RAS, on the other hand, is a unique kit that provides everything you want in a suspension system without any trade-offs. It eliminates bottoming out like air springs, reduces sway and body roll like sway bars, keeps your ride level like helper springs, and improves traction and braking control like traction bars. This improves your vehicle's stability, handling, and control while you are towing or hauling, as well as when your vehicle is unloaded. RAS also makes your overall driving and towing experience safer and more comfortable, which greatly lessens driver fatigue.


How RAS Works

Close-Up of RAS Tension Spring

Each RAS unit has a powerful variable-rated coil tension spring that converts your passive leaf spring into a mechanically-active system. Once your vehicle is loaded, the tension springs immediately activate to absorb and support the weight. This allows your leaf springs to maintain their bowed position and keeps them from flattening out or flipping over, which greatly hinders their ability to bear a heavy load. The tension springs are variable-rated, which means that the heavier your load is, the more assistance they provide to your leaf springs. Because of this design, RAS reacts instantaneously, whereas hydraulics, air springs, and other suspension systems take time to react. And unlike your factory leaf springs, RAS stops sway and sag before they even start to happen. Additionally, when your vehicle is unloaded, the tension springs disengage, allowing your leaf springs to perform as intended without hardening your ride. RAS won't hinder your leaf springs' movement, nor will it cause any friction between any of the brackets.


Eliminates Axle Wrap and Wheel Hop

RAS Eliminates Axle Wrap

When under a heavy load, leaf springs are especially susceptible to axle wrap, which can cause wheel hop. Wheel hop is when the tires lose their grip on the road, causing a jarring, up-and-down movement. Axle wrap occurs when the circular motion of the tires cause the leaf springs to twist or rotate. If the leaf springs twist far enough, wheel hop can occur. RAS stabilizes your leaf springs by absorbing the force of the load they're trying to support. This eliminates axle wrap and wheel hop, as well as prevents your vehicle from bottoming out. Because of this, less strain is put on your vehicle. And by reducing some of this wear and tear, RAS helps extend the life of your leaf springs, shock absorbers, shackles, and even tires.


Reduces Sway and Body Roll

RAS eliminates sway and body roll

When driving along a curve while towing or hauling a heavy load, the back end of your vehicle or trailer can start to shift with that weight. If your factory leaf springs have flattened or twisted under this load, they won't be able to prevent it from shifting. Because of this, your trailer will sway away from your vehicle. This makes driving challenging and dangerous, as it increases the risk of body roll, which is when your vehicle drastically leans to one side. This can often cause you to completely lose control of your vehicle. Body roll is especially prevalent with multi-passenger vans and vehicles towing long campers, trailers, or boats. RAS provides a much safer ride by reinforcing your factory leaf springs and stabilizing your load. This helps prevent sway from occurring and reduces the chance of body roll while cornering, turning, and swerving. RAS also lessens the rocking motion that happens during windy conditions or when a semi passes by on the road.


Levels Your Ride and Improves Traction

RAS Levels Your Ride

When your vehicle is overloaded, the bulk of the weight transfers to the rear axle. Your factory leaf springs then become overwhelmed by this weight, as they are not strong enough to support it. This causes the back end of your vehicle to sag and the front end to rise, which means that the front tires have lost some of the grip they need with the road. In addition to loss of traction, it can also cause poor headlight aim, unintentional swerving, and an extremely bumpy and uncomfortable ride. RAS bolsters your factory leaf springs and enables them to provide support for your load without compromising ride quality or comfort. This keeps your ride level from front to back whether you are hauling a load in the bed or towing a boat, trailer, or camper. RAS also ensures that your tires have the traction they require while braking and accelerating, which improves the overall driving experience.


Customizable Coil Tension Springs

Adjusting Spring With Spacer

RAS is also customizable. During installation, the coil tension springs can be adjusted to 2 different tension settings or anywhere in between for improved road handling and support. To do this, rotate the springs while keeping the threaded rod still. As you turn the spring, use one of the 2 included spacers as a gauge to measure the widening gaps between the coils. In order for the RAS units to work as intended, you must tension the coils to a minimum of 25 percent with the 1mm white spacer and no more than 40 percent with the 2mm spacer. The springs can also be independently adjusted to compensate for off-center loads such as a handicap lift.


Easy, Bolt-On Installation

RAS Once Installed

This custom-fit kit comes fully assembled and is easy to install. Each RAS unit simply bolts onto your factory leaf spring with the included hardware, and drilling, welding, and cutting aren't required. First, position the eye hook bracket so that it wraps around the top of the factory leaf spring eye. Then the axle bracket secures under the leaf spring and around the factory U-bolts on the other side of the leaf spring pack. Once the maintenance-free RAS units are fully installed, you won't need to monitor them as you would with air springs.


Corrosion-Resistant Steel Construction

RAS Construction Close-Up

RAS is extremely durable and corrosion-resistant. The units are constructed of high-grade alloy steel, and they have an epoxy e-coat on the coil springs to provide extreme corrosion resistance. The brackets on the ends of each unit resist the effects of water and other elements, and they have a salt spray rating of more than 800 hours.



4614-SAT RAS Custom Active Suspension System for OEM Leaf Springs - Rear Axle

Replaces RAS 4514-SAT

Installation Details RAS4514-SAT Installation instructions

This Product Fits The Following Vehicles





Customer Reviews

Roadmaster Active Suspension Custom Leaf Spring Enhancement Kit - RAS4514-SAT

Average Customer Rating:  4.7 out of 5 stars   (425 Customer Reviews)

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 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:
2011 Toyota Tacoma

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


Comments
Still working great. Towed a Flaggstaff microlite 23LB Travel trailer prob between 5 and 5500 LB’s to Niagra Falls with no problems, truck sat level with trailer and 2 adults,2kids. Getting ready to make a 2,000 mile round trip to disney in florida in a few weeks.
Rich - 03/10/2021

by:
2019 Toyota Tacoma

Had the kit installed today at the local Toyota dealer on a 2019 Tacoma. The truck had a greatly improved ride and seemed to have a more steady rear end feel. I plan on towing an RV in a few weeks and to the mountains in July, and have a greater confidence in performance. It did raise the back a good 2", it doesn't look bad, as I had expected. I firmly believe that this was the right choice, I can't wait to put it to use!



by:

easy install does the job optional adjustment disc was missing but i have installed before and knew what i wanted



by:
2021 Toyota Tacoma

Seems to work as advertised. I installed it on my 2021 Toyota Tacoma. The installation was simple and quick. It took me longer to get the truck jacked up and the tires removed than it did to install the product. My truck has a little less squat with a load and I don’t notice any stiffer ride when empty. I would definitely recommend.



by:

Works great, although I think it should be a little bit better as far as stiffness with a load on.



by:

Great product. It took me longer to round up my tools than it did to install. The video by etrailer was a great help. As always, great service from etrailer and their staff. They really do care about their customers. Have ordered my Blue Ox Sway Pro, hitch ball and tekonsha brake controller from them. You can't go wrong with etrailer.



by:
2014 Toyota Tacoma

Prompt shipping, good price, happy. The Roadmaster was easy to install and works as advertised. Truck used to squat under weight. Now even with the riding mower in the back, I cant even tell its there. No squat and good handling. Unloaded there is no effect on ride. Cranked to max, raised the rear about an inch. Like them.



by:
2013 Toyota Tacoma

Very easy install and so far happy with what I'm seeing it do for my Tacoma. Etrailer did a great job of letting me know when it shipped and would arrive. Great service as always.



by:

Easy to install. The ride is great. I did use the third hole to open up more clearance with the brake line. That worked well.



by:
2013 Toyota Tacoma

Very happy with the Roadmaster active suspension kit. I had it on other trucks before this one, and was always pleased with how it worked, So never thought twice about using it on next truck. Performs well and does everything it is supposed to do. Much better than cheaper items, it will last and be on truck as long as truck last.



by:
Toyota Tacoma

My Tacoma came with tow package but manufacturer doesn’t have an electric brake controller. I didn’t like the look of the after market ones until I checked etrailer. They carry The Redarc that tucks the controller under the dash with a nice looking, back lit , dial that fits in the dash with a factory finished look. Install was plug and play. Adding Roadmaster Helper springs really help to stabilize the Tacoma when towing my camp trailer, or when carrying loads in the bed of the truck.
Thanks etrailer.



by:

Shipment was delayed by manufacturer but you guys kept me updated on status



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2017 Toyota Tacoma



by:

Review from a similar RAS in Vehicle Suspension


Total transformation! I never knew how bad my ride was until I installed these RoadMaster 3611-HD active suspension. It took longer to safely jack my truck up and remove tires than it was to install them! Absolutely a game changer. I carry about 1000 lbs of tools and supplies daily and like riding a Rollercoaster when hitting bumps. Now, i hit bumps on purpose just to feel these RoadMasters work their magic! Love them!


Comments
After a year of use , these RoadMaster 3611-HD active suspensions are still the best addition to my trucks performance. The streets of Houston are brutal and these active suspension breeze through them. I have 354000 on this truck and if I ever get another, this Active Suspension will be the first addition. Hands down!
Tracey T - 04/29/2022

by:

Review from a similar RAS in Vehicle Suspension


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.


Comments
After a year I am still pleased with this product. I had been adjusting the spring tension higher when towing and then back down after a trailering trip, but now just leave it adjusted to the trailer towing tension as the unloaded ride doesnt seem to suffer when the springs are tighter.
Rick M - 03/27/2022

by:

Review from a similar RAS in Vehicle Suspension


Roadmaster active suspension seems to be built very well. I look forward to towing my travel trailer very soon to see if it improves the towing experience.


Comments
It has been a year now since I installed the Roadmaster Active Suspension system on my 2018 F150. We pull a 30 ft travel trailer from Wisconsin to Alabama.Last year the roads became very slippery when we encountered a rain snow mix. The truck and trailer tracked perfectly. I just hooked up the rig yesterday to take the same trip, leaving tomorrow. The truck definitely handles better with the RAS. Im glad I installed it and am sure it will last for years.
Dave H - 01/30/2022

by:

Review from a similar RAS in Vehicle Suspension


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.


Comments
What can I say. After a year of constantly driving through Texas roads and highways. I have moved twice and loaded the bed of my truck plus U-Haul 6x12 trailer and thy truck has not felt the load of it. The Active Road Suspension Leaf Spring is constantly sort of speak sensing if theres load so it can actively push it upwards. I have even driven up to the crazy roads of Pennsylvania and my pick drives smoother than when I got it from the dealer. Im telling you these things work. As any cautious driver upkeeping his own vehicle, I have periodically checked the bolts and location of the resistance in between the spring and it has not deflected or moved from its original installation. I believe every pick up must have these. It beats constantly putting air on the air bags especially in inclement weather like up here in Pennsylvania with the snow. I couldnt be more satisfied with this purchase. Thank you etrailer for offering this superb product.
Sergio R - 08/13/2021
Comments
Just like when I bought it.
Sergio R - 08/16/2021

by:

Review from a similar RAS in Vehicle Suspension


This is my 2nd set of RAS! Just purchased for towing in my D-Max 2500HD. 1st set we’re on a Chevy 1500. I tow a 7000lb 259FKDS Freedom Express bumper pull and having the RAS-HD’s installed is night and day difference in towing. I have them set at 40% because of my cargo in the truck bed and tongue weight. I’m set up right now as I type on a 100 mile camping trip to set the springs and readjust if needed! So I say….”if you need support with towing, give RAS3611-HD a try…you won’t be disappointed with the results”



by:

Review from a similar RAS in Vehicle Suspension


Just had the roadmaster suspension assist installed today. The ride feels a bit smoother and truck back end feels tighter. Have not had a chance to hook up our 28 foot RV but I will be sure to revisit after. So far I feel good about this purchase


Comments
Still working great after 1 year! Sure love how it handles our 28 foot RV. More stable, less swaying and bounce
Forrest F - 04/11/2022

by:

Review from a similar RAS in Vehicle Suspension


Easy to instal on a 2014 F-150 4x4.Used the bump stop spacer even though installation was for 2015-present f-150 4x4. Many thanks to Corin for her help in getting the order sent in a timely manner. The only thing I forgot to do was measure the wheel well height before instal. I used the thicker black disk as I had concerns with tongue weight on the new trailer that I will pickup on Wednesday. Thanks again for the good service.


Comments
Great product. The truck is level when the trailer is hooked up and the stability is very good when getting passed by big rigs.
LRS - 06/23/2022
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425
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