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  1. Anti-Sway Bars
  2. Roadmaster
  3. Anti-Sway Bar
  4. Rear
  5. 1-1/2 Inch Diameter
  6. Steel w Polyurethane Bushing
Roadmaster Rear Anti-Sway Bar - 1-1/2" Diameter

Roadmaster Rear Anti-Sway Bar - 1-1/2" Diameter

Item # RM-1139-147
Our Price: $575.54
You Save: $327.51
Anti-Sway Bars

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Minimize sway and driver fatigue by improving the stability and driveability of your vehicle. The bar on this sturdy, effective anti-sway system mounts to the rear axle and to the frame to balance weight transfer and reduce body roll. 1-800-940-8924 to order Roadmaster anti-sway bars part number RM-1139-147 or order online at Free expert support on all Roadmaster products. Great prices and Fastest Shipping for Roadmaster Rear Anti-Sway Bar - 1-1/2" Diameter. Anti-Sway Bars reviews from real customers.
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Roadmaster Anti-Sway Bars - RM-1139-147

  • Anti-Sway Bar
  • Roadmaster
  • Rear
  • 1-1/2 Inch Diameter
  • Steel w Polyurethane Bushing

Minimize sway and driver fatigue by improving the stability and driveability of your vehicle. The bar on this sturdy, effective anti-sway system mounts to the rear axle and to the frame to balance weight transfer and reduce body roll.


  • Minimizes side-to-side movement to improve overall stability of your vehicle
    • Lets you execute turns and quick maneuvers with confidence
    • Allows for a level ride, even on irregular surfaces
    • Reduces driver fatigue - minimizes effort required to keep your vehicle in line
  • Diminishes effects of crosswinds, passing motorists and shifting cargo
  • Designed to fit your vehicle and work in conjunction with its suspension system
    • Attaches to rear axle and to chassis - uses weight of axle to brace frame as it shifts in turns
    • Engineered to avoid interference with most popular aftermarket add-ons and accessories
  • Made with polyurethane bushings instead of the standard rubber variety for a longer-lasting system
    • Polyurethane is durable and resistant to damage caused by oil, gasoline and ozone
    • Less wear means less give in the system and better support
  • Constructed of thick 4140 chromoly steel for superior strength
  • Includes heavy-gauge mounting hardware, easy-to-follow instructions and bushing lubricant
  • Works with front anti-sway bar (sold separately) for absolute stability - available on certain applications only
  • Made in the USA


  • Bar diameter: 1-1/2"
  • Limited Lifetime Warranty

Roadmaster Anti-Sway Bar Installed

Benefits of an Anti-Sway System

The Roadmaster anti-sway bar does for side-to-side movement what a good pair of shocks does for up-and-down motion. You will notice a marked improvement in your vehicle's stability as the bar works to balance weight transfer and reduce body roll. The anti-sway bar acts as a link between your vehicle's frame and its rear axle, using the axle as a brace to more effectively balance the shifting weight of your vehicle as you maneuver it. Lubricated bushings allow just enough pivot and rotation to compensate for the pressure placed on one side of your vehicle when it goes into sudden maneuvers, hits crosswinds or encounters shifting weights.

Roadmaster Anti-Sway Polyurethane Bushings

Superior Construction

The Roadmaster anti-sway bar is made of 4140 chromoly, a chromium and molybdenum steel alloy. This type of steel is considerably harder and stronger than the standard 1020 steel that is typically used in anti-sway applications. In addition, the larger diameter of the bar increases its torsional roll stiffness. The result is a bar that is not only stronger than the competition, but also nearly 30 percent better at resisting sway. The polyurethane bushings and grommets used at the attachment points are durable yet flexible, ensuring that the system is neither so rigid nor so malleable that it becomes ineffective.

1139-147 Road Master Anti-Sway Bar - Rear

Installation Details RM-1139-147 Installation instructions

This Product Fits The Following Vehicles

Customer Satisfaction Score:

Customer Reviews

Roadmaster Rear Anti-Sway Bar - 1-1/2" Diameter - RM-1139-147

Average Customer Rating:  4.8 out of 5 stars   (1768 Customer Reviews)

Minimize sway and driver fatigue by improving the stability and driveability of your vehicle. The bar on this sturdy, effective anti-sway system mounts to the rear axle and to the frame to balance weight transfer and reduce body roll.


What a phenomenal difference driving my motorhome after upgrading to the Roadmaster swaybars front and back. Install was straightforward and only took an hour or so per axel. Money well spent!

2017 Ford E-Series Cutaway

Fairly easy install. Drilling the hole in the frame was decent started with a 17/64 pilot hole then the 17/32 final hole. Take your time and let the drill do the work.
Do be aware of the hole placement on the drivers side as there are brake lines and wiring there.


This way bar is very thick extremely rigid. The small links that attach it to the frame brittle. They snap and break off right away. The linkages are defective, If you had a tow rope you would not use dental floss to attach it with. That seems to be the case here Made a great big thick sway bar and no way to attach it Correctly. Actually just look at the picture and see the thick sway bar and look at the link I just and you'll wonder how that will work, it won't

Etrailer Expert

Jenny N.


It is unusual that the end links would not hold up. I wanted to ask a few questions. Do you have a Thor Chateau 2019 -2022 E-350 Class C or a 2016-2022 E-450 Class C? Would you be able to send a picture of the end links on your motorhome?


Ordered front and back and steering stabilizer, the anti- sway bars were delivered and I had them installed, the steering stabilizer still has not arrived ordered in March.



Anti sway bars have been on over a year still believe was a great investment holds you steady. As for steering stabilizer that one was never shipped from roadmaster. Went with safe t plus and very happy with it.


Wow, what a difference the sway bars have made. No more fighting with the steering wheel in high winds. Heavy duty quality parts . Can’t wait to get the Exact Center steering stabilizer put on next.


I watched your video on the installation of the rear sway bar which I found to be helpful. I used an adjustable strap to level the sway bar before aligning and drilling for the links. Looking forward to a road test soon. Thank You


Factory installed sway bars were installed when we first purchased our 2018 Four Winds 32’ Class C. It didn’t take long before we noticed this thing was hard to control in strong winds and uneven road surfaces. My hands would get tired from gripping and fighting the steering wheel. I purchased the correct Roadmaster front and rear sway bars and noticed an immediate improvement to handling and and stability. A great relief for me, but also for my wife, who although sits in the passenger seat, critiqued me on the rough ride and my driving ability. Best investment I’ve made so far!


would have given 5 star rating... however had a little problem with the rods connecting to frame....for some reason my frame was different than the one showing how to install sway bar... Very happy with the end result....Class C motorhome handled very well in windy conditions.. Glad I bought the Roadmaster anit-sway bar!!!!


Helped with sway but not with wandering steering.


These sway bars along with the road master steering stabilizer made driving our class c a must add to any motor home. improved handling in wind and trucks passing

2012 Winnebago Aspect Motorhome

After being blown all over the highway on a windy day in my 2012 Winnebago Class-C, I decided to purchase Roadmaster Anti-Sway bars and steering stabilizer. The sway bars and stabilizer were a perfect fit for the 2011 Ford E-450 chassis. After having the parts installed, I immediately felt a remarkable difference in the way my 30' RV handled. I can now drive down the highway without a fear of being sucked into big rigs or being pushed into the next lane under windy conditions. Well worth the money!


This product has performed exceptionally. We experienced extreme winds without significant lane-changing effects on Wyoming highways and very little side to side drift when passed by large trucks. I installed the front sway bar without too much effort but the rear bar was a bit more difficult to install so I had a local Mechanic do the work. I’m very pleased with my purchase.


Product arrived quickly as usual with etrailer. The etrailer video was more handy than the accompanying instructions from Roadmaster. etrailer provided videos for both the early E450 and the later chassis installations. While essentially the same, there was a small difference of enlarging an existing hole on the early frame in my case a 2006 and having to measure to locate the hole on the later. It would be nice if Roadmaster included a parts diagram to help with assembly instead of small not clear pictures. I thought the parts package was short two half inch washers, I supplied them from my stock. The fittings on the Roadmaster bar are much heavier than the stock components. Installation is on a 2007 Coach House, motorhome. Took it for a test drive, big difference in handling.

2022 Ford E-Series Cutaway

ez to install definitely improved the ride going to install front sway bar and steering shock absorber


Upgrade almost complete on my E450 Quantum LF31. Not hard to install the items. Only have the rear sway bar next month and upgrade will be complete. I also have air bags on the back which helped with the weigh transfer on the unit.


Have used this product on a previously owned class C RV. It performed very well.
Side to side sway of the motor home was greatly minimized. Crosswinds and wind pressure from semi traffic had much less impact on the handling of the RV.

2022 Ford E-Series Cutaway

i bought the front and rear anti-sway bars from you, they look really tough om my class c motorhome. I all so bought your sumo springs. with all of this my ride should be great. I also bought a steering stabilizer but from someone else it is a safe-t-plus i can drive down the road no hands on wheel. thank you for all the videos on your wed site and you tube. they where fairly easy to install had to crawl around on the ground under motorhome like videos showed a bit tight some places. But well worth it, thank you


I recently purchased a 2011 Itasca Cambria 28 with only 10,500 miles. Our first trip made it clear that I needed to stiffen the chassis. Unfortunately Roadmaster Anti-sway bars are backordered, and though you should put those on first, I just installed the Steering Dampener. Easy installation though you need to be careful about seating the bushings. The videos are much better than the printed instructions. Already see a big difference in how much tighter the steering is. Can't wait for the bars to arrive. Disappointed to have to wait 4 weeks.



One year later, we have put over 22,000 miles on our rig, and added new tires. The ride is so amazingly better than without the steering stabilizer, and especially the anti sway bars. These additions are absolutely worth the time and money. I would strongly recommend them. You won’t regret it.


We feel sooo much safer.


We’ve had a few trips since we got the front and rear anti sway bars installed on our 32’ motorhome. My son in law does all the driving and he very strongly recommends these. He’s stated that they have made the driving less fatiguing.


Went together with no problems, definitely needed a extra person to install, they said a 17/32” drill was required but I found a 1/2” drill bit worked fine. I’ve already installed the front sway bar which made a big difference in handling so with the rear installed it is great.

2018 Land Rover Freelander

much better than stock sway bar easy install had to drill holes in frame no biggie except my drill bits not sharp have not road tested yet but can tell its going to be sweet to drive shipped super fast too got here two days earlier than expected super stoked great product install was on 2018 ford e 350 super duty coachmen freelander motorhome

2010 Ford F-350, 450, and 550 Cab and Chassis

This review is for the front anti-sway bar I received - the rear is on backorder. Easy to install. Can't believe how much of a difference having just the front anti-sway bar makes! I was a little skeptical of the claims. It is substantially larger than the OEM anti-sway bar. I like that Roadmaster includes the grease for the bushings and the red loctite.

Looking forward to installing the rear anti-sway bar once it arrives, plus the steering stabilizer.

Honda Odyssey

Very sturdy design. Easy to install. I installed this on my 2022 Entegra Odyssey. All of the holes were pre drilled. My unit came with a rear sway bar, but this one was way bigger and works better.


Bottom line - Yes its worth it.
on 2018 THOR/Axis 25.5

Night and Day driving.
Local shop in Maryland installed for me.
(I had already packed my tools/jacks for moving south).
Their mechanic was impressed with the size over the OEM.

On a related note, got the rear set up as well and running Sumo Springs.

Lowell J.


This should be an OEM item, not an add on. Now to upgrade the shocks.

Show More Reviews

See what our Experts say about this Roadmaster Anti-Sway Bars

  • Is There Drilling Required to Install Roadmaster Sway Bar on 2017 Ford E-450 Class A
    The Roadmaster Rear Sway Bar part # RM-1139-147 that fits your 2017 Ford E-450 Class A motorhome does require drilling to install. New holes must be drilled in the frame to mount the Roadmaster end links. If you check out the attached install instruction link you can see more info on this.
    view full answer...
  • How to Improve Control of a Forest River Forester 3011DS
    The most worthwhile upgrade for your Forest River Forester 3011DS on a 2018 Ford E-450 chassis is an upgraded rear sway bar like the Roadmaster Rear Anti-Sway Bar part # RM-1139-147. This is also typically the first thing you upgrade on a new motorhome. The reason for this is because when a large vehicle passes you or a gust of wind hits, the body will begin to rock side to side. This side to side motion causes counter steering which then makes you feel like you no longer have control...
    view full answer...
  • What Drilling is Required to Install the Roadmaster Sway Bar on a Ford E-450 Class C Motorhome
    The reason there is drilling required to install the Roadmaster Rear Anti-Sway Bar # RM-1139-147 on your 2004 Ford Super Duty Class C motorhome is because the end links mount in a different location on the Roadmaster unit than the OEM unit. Check out the installation instructions I attached to see this as well.
    view full answer...
  • Rear Sway Bar Upgrade Recommendation for 2007 Class C RV on Ford E-450 Chassis
    For your 2007 Class C RV built on a Ford E-450 chassis we only have a rear sway bar available part # RM-1139-147. The good news is the rear sway bar upgrade is the single biggest improvement you can make to an RV's ride quality. This will be a great option for you.
    view full answer...
  • Recommended Roadmaster Anti-Sway Bar For a 2010 Fleetwood Jamboree E450
    I contacted our representative at Roadmaster and he confirmed that the Roadmaster Anti-Sway Bar, part # RM-1139-147, is the correct rear anti-sway bar for your 2010 Fleetwood Jamboree Sport E450 31N. If you would like a front anti-sway bar, we also have the Roadmaster Front Anti-Sway Bar, part # RM-1139-176. I have linked instructions for the Roadmaster Anti-Sway Bar, part # RM-1139-147.
    view full answer...
  • Which Rear Sway Bar Will Fit on a 2019 Ford E350 Cutaway Chassis
    Yes. According to Roadmaster, the # RM-1139-147 can be used on the Ford E-350 Cutaway models, as well as the E-450. I've linked an installation video of this sway bar on a similar E-Series for you to have a look at and use as a reference if you're going to be installing it yourself.
    view full answer...
  • Correct Rear Anti-Sway Bar for a 2017 Thor Axis Motorhome with Ford E-450 Chassis
    Thanks for reaching out! The correct rear anti-sway bar for your 2017 Thor Axis on the Ford E-450 chassis is part # RM-1139-147. We've had the chance to install this on a 2017 Chassis so I've linked that and the installation instructions for you to check out.
    view full answer...
  • Why are RVs So Prone to Swaying and Why Don't Chassis Manufacturers have a Solution
    The issue with RV chassis's is that the manufacturers (like Ford) make them but they don't know where the weight of the RV is going to be and since every RV is made a little bit different it's hard for them to foresee exactly how every RV will react on the highway. Best option though is to go with a heavier duty rear sway bar. Which for that you'd want the Roadmaster kit part # RM-1139-147 which is a confirmed fit for your 2015 Jayco Redhawk on an E-450 chassis.
    view full answer...
  • Rear Sway Bar Recommendation for RV Built on 2015 Ford E-450 Cutaway
    For your 2015 RV built on a Ford E-450 cutaway chassis the best rear sway bar we offer is the part # RM-1139-147 which is a confirmed fit. The rear sway bars are the suspension modification that makes the best improvement in ride quality so I know this will work very well for you. To see the install process check out the install video I attached. A 17/32 inch size hole will need to be drilled. The torque specs are listed in the 7th step of the instructions that are attached in a link...
    view full answer...
  • Rear Sway Bar Recommendation for a 2007 Ford E-450 Fleetwood Jamboree 26J
    We have a solution that will help the ride quality of your 2007 Ford E-450 motorhome, but none of the track bars will work with the air suspension. Instead you would want a rear sway bar part # RM-1139-147. This mounts to the rear axle and to the frame to balance weight transfer and reduce body roll. I attached an install video for you to check out as well.
    view full answer...
  • Do I Have to Drill Holes in My 2018 Ford E-450 Frame to Install Roadmaster Rear Anti-Sway Bar
    Thanks for reaching back out and pointing out the video you found that in! I checked out the video you referenced about the Roadmaster Rear Anti-Sway Bar # RM-1139-147 install on a 2019 Ford E-Series Cutaway (see linked) and while Ryan did ultimately install the links back to where the factory ones were located, he only did so because he was unable to properly drill and install the links into the vertical position like the instructions called for. The sway bar will still work like this...
    view full answer...
  • How Can I Combat Against Crosswind And Sway On My 2020 Thor Axis 24.1?
    In order to combat against wind on your 2020 Thor Axis 24.1 for better steering and stabilization, you'll want to invest into a rear anti-sway bar. Take a look at the: - Roadmaster Rear Anti-Sway Bar # RM-1139-147, This anti-sway bar is actually confirmed to fit your motorhome, will do a great job of minimizing side-to-side movement to improve overall stability of your vehicle, and will diminish the effects of crosswinds, passing motorists, and shifting cargo. Included is a product...
    view full answer...
  • Front and Rear Sway Bar Recommendation for 2017 Ford E-450
    For a front sway bar for the 2017 Ford E-450 you'll want to use the Roadmaster # RM-1139-176. This part will replace the existing sway bar, but will reuse the factory hardware and end links. A rear sway bar is also available as part # RM-1139-147.
    view full answer...
  • Upgraded Anti-Sway Bars for a 2020 Entegra Class C Motorhome
    The most worthwhile upgrade you can make to a motorhome's suspension is an upgraded rear anti-sway bar, the Roadmaster Rear Anti-Sway Bar part # RM-1139-147. The rear anti-sway bar is going to do a great job of increasing stability like helping to keep the motorhome on the road when trucks pass by or when making turns. The front upgraded anti-sway bar, the Roadmaster Front Anti-Sway Bar part # RM-1139-176 is still a good option but not what I recommend to start.
    view full answer...
  • Recommended Front And Rear Anti-Sway Bars For A 2022 Minnie Winnie 26T Class C Motorhome
    You were right on with the part # RM-1139-176 for the front sway bar and part # RM-1139-147 for the rear sway bar on your 2022 Minnie Winnie 26T Class C Motorhome. These sway bar kits will come with everything you need to complete the installation, besides the tools of course.
    view full answer...
  • Recommended Anti-Sway Bars for a 2018 Coachmen 31 Class C w/E450 Chassis
    The sway issues you are experiencing have little to do with the tires because the sway you feel is movement of the frame. I recommend you use the Roadmaster Rear Anti-Sway # RM-1139-147 and the Front Anti-Sway # RM-1139-176. These bars will stabilize the side to side movement by balancing the weight transfer and reduce body roll. Many people choose to add all of these components and there is a remarkable difference to the driving experience when you do. If you can't add them all, I...
    view full answer...
  • Sway Bar For 2018 Thor Freedom Elite 29FE
    I did some checking and since your 2018 Thor Freedom Elite 29FE is built on a Ford E-450 chassis with a V10 engine the rear sway bar you'd want is the part # RM-1139-147 and then for the front you'd want # RM-1139-176. This will dramatically improve the ride and handling of your motorhome.
    view full answer...
  • Recommended Sway Bars for a 2018 Jayco Redhawk Class C on a Ford E-450 Chassis
    From my research your 2018 Jayco Redhawk 31XL is a Class C motorhome built on a Ford E-450 chassis with a V10 engine. To improve the steering on your Jayco you'll gain the most improvement from the rear Rear Anti-Sway Bar # RM-1139-147. That would be followed by the Front Anti-Sway # RM-1139-176.
    view full answer...
  • Recommended Anti-Sway Bars for 2021 Thor Axis 25.6 on Ford E-450 Chassis
    For your 2021 Thor Axis on Ford E450 Chassis, you will want the Roadmaster Rear Anti-Sway Bar # RM-1139-147 and the Roadmaster Front Anti-Sway Bar # RM-1139-176. The rear anti-sway bar is the biggest impact because the enhanced stability greatly impacts the body roll and the rear axle positioning requires more stabilizing overall. The front anti-sway is the next thing we recommend adding as it helps keep the front end more stable which helps with steering as well but this is the second...
    view full answer...
  • Front and Rear Sway Bar and Steering Stabilizer Recommendation for 2016 Class C Ford E-450 RV
    You'll want to use the Roadmaster # RM-1139-176. This part will replace the existing sway bar, but will reuse the factory hardware and end links. A rear sway bar is also available as part # RM-1139-147.
    view full answer...
  • Recommended Anti-Sway Bar for 2022 Ford E450 Series with V8 Engine
    For your Class C motorhome on a 2022 Ford E-450 chassis, I recommend the highly rated Roadmaster Rear Anti-Sway Bar, # RM-1139-147. This is a 1-1/2" diameter anti-sway bar made from 4140 chromoly steel that replaces the factory bar. The effectiveness of the Roadmaster anti-sway bars is in the diameter and quality of the steel they are constructed from. Roadmaster claims that for every 1/8" increase in diameter there is roughly a 30% increase in torsional resistance (body roll). Their...
    view full answer...
  • Front Sway Bar Recommendation for a 2011 Ford E450 Motorhome Chassis
    You said you have a 2011 E450 motorhome that is a Class B. That we are aware of there are only Class C and Class EV Type 3 E450 chassis's. Which either way you can upgrade just the front sway bar and it would help you with the sway from the wind a great deal. Either model of 2011 Ford E450 requires the Roadmaster Front Sway Bar part # RM-1139-176 that you referenced. If you decide you want to go with a rear bar as well in the future you would want part # RM-1139-147.
    view full answer...
  • Rear Sway Bar that Fits 2018 Thor Vegas 25.2
    I checked with Roadmaster and the correct rear sway bar for your 2018 Thor Vegas 25.2 is the part # RM-1139-147 since it was built on a Ford E-450 Class A chassis. The part number you mentioned does not fit.
    view full answer...
  • Sway Bar Fit and Recommendations for a 2016 Jayco RV on E-450 Chassis
    Yes, the sway bar fits from a 2015 RV built on an E-450 chassis are the same as for a 2016. The Roadmaster Front Anti-Sway Bar # RM-1139-176 that you referenced is a fit for your RV. For a rear anti-sway bar you can use # RM-1139-147 which will provide an upgraded bar and bushings to improve stability at the back of the RV.
    view full answer...

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