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  1. Vehicle Suspension
  2. RAS
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  4. Towing/Load Leveling
  5. Rear Axle Suspension Enhancement
  6. Heavy Duty
RoadActive Suspension Custom Leaf Spring Enhancement Kit - Heavy Duty
RAS

RoadActive Suspension Custom Leaf Spring Enhancement Kit - Heavy Duty

Part Number: RAS34FR
In Stock
$589.00
Vehicle Suspension

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3,000-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 - Heavy Duty part number RAS34FR can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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RAS Vehicle Suspension - RAS34FR

  • Leaf Springs and Helper Springs
  • Towing/Load Leveling
  • RAS
  • Rear Axle Suspension Enhancement
  • Heavy Duty
  • Suspension Only
  • Helper Springs

3,000-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:

  • Heavy-duty 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: 3,000 lbs
    • RoadActive 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

RoadActive 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.



4611-TDHD RAS Custom HD Active Suspension System for OEM Leaf Springs - Rear Axle

Installation Details RAS34FR Installation instructions

This Product Fits The Following Vehicles




Customer Satisfaction Score:

Ratings & Reviews

4.7

591 reviews
3,000-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.

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Show More Reviews

See what our Experts say about this RAS Vehicle Suspension

  • Recommendation to Stop Bounce When Towing Trailer With 2019 Toyota Tundra
    Hey Steve, with this problem we have seen people have great luck fixing it by installing a Roadactive suspension kit like the part # RAS34FR that is a confirmed fit for your 2019 Toyota Tundra. The additional suspension support provided to the truck does a great job making that stop as well as has the side benefit of improving unloaded ride quality and handling as well. Did it seem any worse or better than your Expedition?
    view full answer...
  • Is SumoSprings or RoadActive Suspension Better For 2008 Toyota Tundra
    For your 2008 Toyota Tundra, between the SumoSprings Solo Custom Helper Springs # SSR-610-54 and the RoadActive Suspension (RAS) Custom Leaf Spring Enhancement Kit # RAS4611TD, the better overall system is the RAS # RAS4611TD. The reason for that is the RAS is an active system which continually reinforces your Tundra's original leaf spring suspension. The force normally put on its leaf springs, either when carrying cargo or towing a trailer like you are, gets transferred to the RAS Enhancement...
    view full answer...
  • Will RoadActive Suspension Work On 2007 Toyota Tundra With Icon Leaf Springs?
    Hello Karim, thanks for reaching out. Yes the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS34FR will still work with your Icon aftermarket leaf springs. We have confirmed this with many of our own customers who have successfully used RAS with Icon leaf springs. This system simply clamps to the leaf spring stack at the center and the opposite side eyelet to act as an extra leaf spring on the stack and provide more support for heavy loads. It will definitely help with stability...
    view full answer...
  • Best Rear Suspension Enhancement Recommendation for 2010 Toyota Tundra Double Cab with Camper
    Hey Joe, the best suspension enhancement kit we offer for your 2010 Toyota Tundra is the Roadactive kit part # RAS34FR. This is easy to install, maintenance free, and improves ride quality and handlining loaded and unloaded which is basically unheard of. The best bang for your buck is the Hellwig EZ-990 # HE86VR which has by far the best price. It basically adds a leaf to your rear suspension for more support. If you are wanting something that costs less and will do an excellent job but...
    view full answer...
  • Recommended Alternative to Air Bags on 2017 Toyota Tundra
    You can't beat air bags when it comes to support and adjustability but that does mean you can't just install them and forget it. The RAS # RAS34FR is a good alternative option that won't require maintenance. These will add extra support and reduce sway and body roll without hurting your ride quality. It does have multiple settings so technically you can adjust them if need be based on what you're doing. In most cases you will set them up the first time and that will be the end of it.
    view full answer...
  • Will RAS Kit Help With Sagging On 2016 Toyota Tundra While Towing 5th Wheel
    Hello Donald, thanks for reaching out. The RAS kit for the 2016 Toyota Tundra part # RAS34FR will help with overall stability and will help reduce sagging. It may not take care of 100% of the sagging, but will definitely make a notifiable difference when towing your 5th wheel. If you want something that is a straight forward one-and-done install, the RAS is a great option. If you want something to eliminate 100% of the sagging, an air bag kit like the # F2445 is what I would recommend....
    view full answer...
  • Roadactive Suspension Kit for 2017 Toyota Tundra Towing Trailer with V-Nose
    Hey Trae, so weight distribution can be used on trailers that have v-noses like what yours has but you have to use bolt on chain hangers that will sit under the v-nose. Now with that said for the weight of your trailer I would actually just go with a Roadactive suspension kit part # RAS34FR. This gives you the support you are wanting to reduce the sag and is a lot less of a headache than dealing with WD on a v-nose trailer and the harshness of a Timbren. Unlike other options the RAS kits...
    view full answer...
  • Timbren Suspension Enhancement that Fits 2013 Toyota Tundra
    For your 2013 Toyota Tundra that is towing a 6,500 lb travel trailer I'd go with the Timbren kit part # TABSOSR to help support the rear of it and reduce sag as this will give you up to an additional 3,600 lbs of support if needed. Other kits provide even more support but they would provide a harsher ride quality. With that said, I think your best option would be the RoadActive Suspension kit part # RAS34FR which provides adjustable support, is easy to install, and also provides the best...
    view full answer...
  • Recommended RAS Suspension Enhancement For 2010 Toyota Tundra 5.7L 2WD Towing 8000lb Travel Trailer
    For your 2010 Toyota Tundra 2WD with a Snug Top Camper Shel towing a 34' Travel Trailer with 800lbs tongue weight and 8000lb trailer weight using a weight distribution hitch I recommend the RoadActive Suspension Heavy Duty # RAS34FR with a 3000lb load capacity. This kit can be adjusted in two ways depending on the exact stiffness and load support you want, but in your case I would go ahead and use the lower setting which is the thinner spacer. The reason I recommend going with the Heavy...
    view full answer...
  • Comparing RAS Leaf Spring Enhancement Kits RAS34FR and RAS4611TD For 2017 Toyota Tundra
    You are correct that there are two RoadActive Suspension Leaf Spring Enhancement Kits for your 2017 Toyota Tundra, the # RAS34FR which has a 3000lb capacity and the # RAS4611TD with a 2000lb capacity. Between these two kits I recommend going with the # RAS34FR as it will give the most support to your suspension. These kits will not negatively affect your unloaded ride so there is not a down side in going with the heavier duty system. With the # RAS34FR you will not only get less squatting,...
    view full answer...
  • Will Firestone Air Springs Fit A 2020 Toyota Tundra With A B&W Turnoverball Gooseneck Hitch
    Hey Kevin, The Firestone Ride-Rite Air Helper Springs # F2445 are unfortunately not compatible with your B&W Turnoverball Underbed Gooseneck Trailer Hitch # BWGNRK1257 because it has a mounting bolt right where the spring would need to sit. In order to help support your suspension while towing you'll need to go with an upgrade that doesn't contact this bolt so I recommend the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS34FR. This system clamps onto the leaf springs to...
    view full answer...
  • Best Suspension Enhancement System for a 2021 Toyota Tundra For a Self-Install
    I have a great suspension enhancement system that you can install on your 2021 Toyota Tundra. The RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS34FR is going to be a great option to improve your vehicle's stability, handling, and control while you are towing or hauling, as well as when your vehicle is unloaded. 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,...
    view full answer...
  • Can RAS34FR RoadActive Suspension System Be Used Along With Weight Distribution
    The US- made # RAS34FR RoadActive Suspension kit is a fit for your 2006 Toyota Tundra and would be an excellent addition to augment your rear suspension and to improve your ride quality whether the truck is loaded or unloaded, towing or not. The system will work along with your Equal-i-zer weight distribution system to level out your ride height between the front and rear axles and will also help prevent axle wrap and wheel hop. You'll want to be sure to repeat the set-up procedure for...
    view full answer...
  • Do I Have To Remove The Leaf Spring Eye Bolt To Install?
    That's a good question. I have seen videos of this product installed and many times the (part C) eye bracket hook just lays onto the leaf spring eye. However, since 2008 the Tundra's have required one side of the eye hook to be removed. I have attached the install procedure PDF file. Step 6 reads, "Remove one side and place it on top of the rear leaf spring eye bracket hook." They certainly could have provided a picture illustrating this and a better explanation. So yes, you do have...
    view full answer...
  • Will the RoadActive Suspension for a 2017 Toyota Tundra Affect Payload
    The RoadActive Suspension Custom Leaf Spring Enhancement Kit part # RAS34FR for a 2017 Toyota Tundra has a pre-load after installation so it would be considered sprung mass. It essentially becomes part of the leaf spring. They however will not increase payload. In regards to braking, the affects would be marginal but the pre-load will place more weight towards the front axle where the majority of the braking force will be.
    view full answer...
  • How is the RAS System Different From Add-A-Leaf System for 2001 Toyota Tundra
    An Add-A-Leaf kit differs from the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS34FR for your 2001 Toyota Tundra in that the Add-A-Leaf is literally just adding another leaf spring to your spring stack to help make it a little more robust where the RAS system is a little more "smart". It has a spring that helps to provide constant tension and you can adjust it some for more of a relaxed or stiffer ride quality. So instead of just making your leaf spring stack thicker...
    view full answer...
  • Can You Install Both SuperSprings and SumoSprings on a 2016 Toyota Tundra
    I do have an option for but SumoSprings Solo Custom Helper Springs like part # SSR-610-54 and SuperSprings Custom Suspension Stabilizer and Sway Control Kit part # SSA4 won't work together on a 2016 Toyota Tundra since they both mount in the same location. If you need more support, I recommend removing the SuperSprings Custom Suspension Stabilizer and installing the RoadActive Suspension Custom Leaf Spring Enhancement Kit part # RAS34FR which is very similar but provides almost three times...
    view full answer...
  • Will The RoadActive Suspension Work With 2" Lift Block On a 2018 Toyota Tundra?
    Since the RoadActive Suspension Custom Leaf Spring Enhancement Kit # RAS34FR only connects to the rear leaf spring on your 2018 Toyota Tundra it will still work with the 2" block you have between the leaf spring and the axle.
    view full answer...
  • Best Suspension Enhancement for 2021 Tundra SR5 4x4 Towing Trailer
    The best suspension enhancement for your 2021 Toyota Tundra is by far the RoadActive Suspension kit part # RAS34FR as it gives you the support you are wanting to prevent sag, doesn't hurt loaded or unloaded ride quality, and also improves handling and side to side stability.
    view full answer...
  • Helper Spring Recommendation For Rear End Sag While Towing With 2021 Toyota Tundra TRD PRO
    If the vehicle still squats even when using weight distribution, my first suspicion would be that the weight distribution system hasn't been set up correctly or the system being used is under-rated for the travel trailer's tongue weight + the weight of anything that's carried in the truck bed behind the rear axle. I'd suggest revisiting the initial setup to ensure things have been set up correctly. I'd also recommend confirming the the travel trailers fully loaded and ready to tow tongue...
    view full answer...
  • Can I use a RoadActive Suspension Kit and a Timbren System on a 2021 Tundra
    I recommend using just the RoadActive Suspension Custom Leaf Spring Enhancement Kit - Heavy Duty item # RAS34FR and making sure it is adjusted properly. Yes, those 2 systems can both be installed on your 2021 Toyota Tundra. However, both of them combined would be a stiff uncomfortable ride.
    view full answer...
  • Will the RoadActive Suspension System Lift the Bed of an Already Lifted Truck
    The RoadActive Suspension system # RAS34FR effects the suspension, so it will work with any body lift that you may have in place. The RAS system will lift the rear of the vehicle approximately 1" to 1-3/4" depending on the truck, so the bed is also going to raise up in the process that same amount- so it's going to be in addition to whatever body lift has already been added.
    view full answer...
  • Suspension Enhancement Recommendation for 2008 Toyota Tundra with Gooseneck Hitch
    For your 2008 Toyota Tundra the suspension enhancement I would recommend the highest is the RoadActive Suspension kit part # RAS34FR as it gives you adjustable support like you are wanting but it also gives you a better ride quality and handling unlike the other options so it's the best overall solution.
    view full answer...
  • Suspension Enhancement Recommendation for 2016 Toyota Tundra 4WD Towing Trailer
    I have a really great solution to give you additional suspension support and will also improve the ride quality and handling the RAS systems like the part # RAS34FR that fits your 2016 Toyota Tundra. I wouldn't recommend front suspension enhancement for your setup. That would most likely actually make the ride quality harsher. Any of the other rear suspension enhancement options would also make the ride quality a bit rougher as well so that's why I would not recommend them for you.
    view full answer...


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Info for this part was:

Employee Mike L
Expert Research:
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Employee Jeff D
Installed by:
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