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  1. Anti-Sway Bars
  2. Roadmaster
  3. Anti-Sway Bar
  4. Rear
  5. 1-1/2 Inch Diameter
  6. Mounting Hardware Included
THIS ITEM IS NOT A FIT FOR
2018 Ram 3500
Roadmaster

Roadmaster Rear Anti-Sway Bar - 1-3/8" Diameter

Part Number: RM66GR
In Stock
$960.00
Retail:$1,065.47
You Save: $105.47
Anti-Sway Bars
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2018 Ram 3500

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Minimize sway and driver fatigue by improving the stability and driveability of your Ram 3500. 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 RM66GR or order online at etrailer.com. Free expert support on all Roadmaster products. Great prices and Fastest Shipping for Roadmaster Rear Anti-Sway Bar - 1-3/8" Diameter. Anti-Sway Bars reviews from real customers.
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Ram 3500 - Roadmaster Rear Anti-Sway Bar - 1-3/8" Diameter

Highlights

  • Custom Fit for Your Vehicle: Tuned to your suspension for better control and stability.
  • Reduces Sway: 1-3/8" 4140 chromoly steel bar minimizes side-to-side movement for steadier control.
  • Handles Crosswinds: Keeps your rig level through gusts, passing traffic, and shifting cargo loads.
  • Less Driver Fatigue: Cuts constant steering corrections so long trips feel smoother and easier.
  • Improves Cornering: Balances weight transfer to reduce body roll and sharpen handling on turns.
  • Uses Existing Mounts: Bolts to rear axle and frame with included hardware—no drilling required.
Made in USA

Features to know about

Flatter, More Controlled Cornering: 1-3/8" Rear Anti-Sway Bar

Big body roll makes every turn feel like a balancing act. The 1-3/8" diameter Roadmaster rear anti-sway bar ties the chassis and rear axle together to keep the vehicle level through corners. Made of thick 4140 chromoly steel, it resists twist far better than standard 1020 steel. The result is tighter, more predictable handling and a big cut in side-to-side sway when the road gets curvy.

Roadmaster rear anti-sway bar installed on a vehicle’s rear axle, showing how it attaches to the chassis and improves stability by reducing side-to-side sway.

Confidence in Crosswinds: Balanced Weight Transfer

Crosswinds and passing trucks won’t push you around anymore. This bar uses the weight of the rear axle to brace the frame as it shifts, countering the side forces that cause sway and steering corrections. It keeps the ride level even when the wind picks up or your load shifts, so the steering stays steady and you stay in control.

Less Fatigue Behind the Wheel: Stable, Predictable Handling

Constantly correcting the wheel wears you out fast. By reducing sway and body roll, this setup makes highway driving smoother and less stressful. It takes less effort to hold your line, even when you’re dealing with gusty conditions or rough pavement. That means you arrive more relaxed and ready for whatever’s next.

Built to Last: Polyurethane Bushings and Heavy-Gauge Hardware

Instead of soft rubber, this system uses polyurethane bushings that stand up to oil, gasoline, and ozone without breaking down. They flex just enough to keep motion smooth but don’t squish out or wear quickly. The heavy-gauge mounting hardware and included bushing lubricant make for a solid, long-term install that stays tight and quiet.

Close-up of Roadmaster anti-sway bar polyurethane bushings and grommets, displaying durable construction and material quality for long-lasting performance.

Straightforward Install: No Drilling Required

Nobody wants to drill into their frame to fix handling. This anti-sway bar bolts on using the included mounting hardware, no frame mods needed. The fit avoids interference with most aftermarket suspension add-ons, so you can pair it with other upgrades without hassle.

Specs

Dimensions

  • Bar diameter: 1-3/8"

Warranty

  • Limited Lifetime Warranty

1129-128 Road Master Anti-Sway Bar - Rear

Installation Details RM66GR Installation instructions

This Product Fits The Following Vehicles




Video of Roadmaster Rear Anti-Sway Bar - 1-3/8" Diameter
Video Thumbnail Video Player Dialog

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for What to Know About the Roadmaster Rear Anti-Sway Bar-RM66GR

Hi, everybody. Andy here with etrailer.com. Let's take a look at this Roadmaster rear anti-sway bar. Now, this anti-sway bar is designed to fit your 2003 to 2008 Dodge Ram 1500, and then your 2003 to 2013 Dodge Ram and Ram 2500, then your 2003 to 2014 Dodge Ram 3500, and then finally your 2010 to 2017 Ram 350 four-wheel drive. Now on custom fit parts such as this anti-sway bar, I do recommend taking advantage of our vehicle fit guide. Simply input the year, make, and model of your vehicle and our fit guide will confirm if this will work for you or if we have something comparable that will work for you.

Now, this bar is going to mount to the rear axle into the frame of your truck to help minimize that side-to-side movement, improving the overall stability of your truck. This system is going to let you execute turns and quick maneuvers with confidence, giving you a level ride even on irregular surfaces. And this is also going to help reduce driver fatigue by minimizing the effort required to keep your truck in line. This is also going to help diminish the effects of crosswinds, shifting cargo, and passing motorists. Now, this anti-sway bar does for side-to-side movement what a good pair of shocks does for up and down motion, giving you a marked improvement in the stability of your truck.

This anti-sway bar acts as a link between your truck's frame and its rear axle using the axle as a brace to more effectively balance the shifting weight of your truck as you maneuver it. It has been engineered to avoid interference with most popular aftermarket add-ons and accessories. And the diameter of this bar is 1-3/8 inches. This is made here in the USA of 4140 chromoly steel, giving you that superior strength. And 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. Now, this will work with a front anti-sway bar. Obviously that is sold separately from this and that's gonna give you absolute stability. And front anti-sway bars are available on certain applications only, so to see if a front anti-sway bar will work for you, again, take advantage of our vehicle fit guide. I do wanna point out that the bushings here are made of polyurethane instead of the standard rubber variety for a longer lasting system.

They're durable and resistant to damage caused by oil, gasoline, and ozone. So as you know, less wear means less give in the system and better overall support. Now, this is going to include everything that you see here on the table before me. You're gonna receive a set of instructions to guide you through the installation process. You're gonna get a tub of bushing lubricant and a vial of Loctite, and then the heavy gauge mounting hardware and end links. All of this is included with this kit. And this does have a limited lifetime warranty from Roadmaster. Well, that's gonna wrap up our look today. I do hope that it was helpful for you. Again, my name is Andy. Thank you for joining me.

Ratings & Reviews

4.8

2475 reviews
5 Stars
(2124)
4 Stars
(243)
3 Stars
(45)
2 Stars
(21)
1 Star
(42)
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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.

by:

I prefer to purchase direct from most manufacturers due to tech support and service. However I find myself purchasing from etrailer.com more and more due to the positive experience, expert tech chat advice, fast shipping and great prices to name just a few. It makes all the difference knowing that you are communicating with a real person and not AI. The Roadmaster 1 3/8” rear sway bar has been my most effective purchase for my truck to date. The SuperSprings SuperSway Stops are right up there in effectiveness as with the rear sway bar. The rear sway bar and SuperSprings SuperSway Stops were very easy to install and I feel like I am driving a different truck. In combination, the two purchases have made the truck and camper feel like one vehicle; no longer does it feel like a truck with something in the bed. VERY stable on turns, twists, hills and angles. I cannot recommend these products enough.



by:

Even though I am driving a 28ft class a rv, the sway bar make a 100% improvement in the handeling



by:

I had a helwig system factory installed on my class C when i bought it in 2020. It was ok as i did not know any better. After 6 years of traveling there was a lot of sway and sagging. So i upgraded to this heavy duty Roadmaster system. What a major difference. the RV rides much more steady and smoothly, and i like it. I think the hellwig that was factory installed was the cheapest system they could find, so they could put the name on. I like Roadmaster equipment much better. Working with Roadmaster and E-trailer makes purchasing, installation and tech support much easier.



by:

Excellent product, easy to install, definitely an upgrade from the oem. Removed the factory stabilizer and installed the roadmaster bar by myself in less than 2 hours. Installed on my 2023 Ram 2500HD.



by:

I bought a motorhome (2014) that only had 24k miles on it. Driving it home two hours was a nightmare and I quickly realized why it only had 24k miles on it! Had this upgraded antisway bar put on it as well as an upgraded front bar and it made a huge difference. It allowed me to make a 2500 mile trip to visit with a sick relative for 10 days!



by:

I submistted a review for both front and rear kits. Both etrailer and Roadmaster are great companies to purchase products. Roadmaster made custom parts and sent them within days.



by:

What an unbelievable difference on my Fleetwood Class A Motorhome. Paired it with a new Rear anti sway bar and 4 new Koni EVO shocks. The handleing and steering are much improved and no more tail wagging in heavy winds, much more enjoyable to drive and no driver fatigue after long driving days.



by:

Installation was 6/10 in difficulty only because of obstacles in the way of the top bolt on the passenger side end link. This was a step up to a 1 3/4" bar from the factory 1 1/2" bar. The end links were much beefier than the factory ones.
Initial test drive - I was impressed that the front roll on curvy roads was greatly decreased. This has been a significant improvement to driveability.



by:

What a difference with my 5th wheel pull. So much better than the tiny stock anti-sway bar. Along with airbags everything is perfact, level, and tows like a dream. This is fully maxing out my Ram 2500 Limited at 20k lbs.



by:

The product is great! All the other positive reviews of the product are accurate. However, the instructions were not for my vehicle and required a phone call for clarification. Waited about 10 mins on hold to talk to someone but this was on a Sunday so I was surprised that anyone answered. Good job on that. I purchased this item because the ad said no drilling. Step 3 in the instructions was to drill. I passed this on to the folks at etrailer and they agreed this was incorrect and offered a free return to correct the issue. As of 23 May 26 the ad has not been corrected so beware. I needed the item so it went from something I was going to install to something I needed to get installed. Finding an installer for an aftermarket part that requires drilling into your vehicle and wasn't sold by the installer was far more difficult than I thought it would be. Thankfully the guys at my local Air Force base auto hobby shop were up for the task and did a great job. Of course there is additional cost. 3 x $40 an hr for my time trying to install myself, reinstalling original gear, finding an installer and logistics of getting vehicle to and from shop. People dont generally value there time accurately. If you had to take time off work 1hr x $40 which I did should also be calculated. With the installer fees this amounted to an additional $380. That's additional cost to me because of a poorly advertised item. This is the part that bugs me about etrailer. They were very friendly on the phone and tried to be helpful with the instructions but other than returning the item, didn't offer a discount for the added frustration or even a coupon for a future purchase. This of course is not required of them but for a purchase as expensive as this you might think this would be a no brainer. I think they could do better.



by:

As others have said the sway bar is good but the directions could be improved. Removing the old down link on the drivers side is a bit of a challenge as you can't easily remove the old bracket until you remove the downlink. Unfortunately you can't get the bolt holding the link to the bracket without supporting the fuel tank and removing the rear strap so that you can push the tank over far enough to get the bolt out. Another issue was the old U brackets holding up the old sway bar were on 3" centers where the new bracket is on 2 3/4" centers. This looks like an insurmountable problem until you remove the star washers holding the old bolts where you can see there is a slot which allows you to use the bolts included. The old bolts were both attached to a plate which kept made the center distance between the bolts non adjustable so using the old bolts is not an option. On the passenger side the plate holding the 2 bolts was connected to the axle connection for the height sensing proportioning valve. I removed the 3 bolts holding it, took out the plate and cut off the front most bolt and reinstalled the plate. Fortunately that allowed me to use the old bolt in the plate and for the front most bolt I used one from the kit and achieved the 2 3/4" center spacing needed for the new bracket. All of this would be nice to know when you tackle this job. Fortunately I had all the tools needed to complete the job. I found it easy to install the new bar despite its weight by lifting up one end of the sway bar and loosely attaching it to the the down link. I then did the other side and once both ends were attached I put the center of the bar on my hydraulic jack and lifted it into place. This made it a fairly easy job to position and attach the U brackets to the axle despite the heavy weight of the bar. A video of this process on an older (1998 vintage) Dodge Ram 2500 would be a big help.



by:

We were told this sway bar might not work on our Dodge Ram3500 dually. Let me tell you this worked great. Our truck has a camper on top and we took this on a long trip and it worked great. What a difference it made. This trip had lots of very high winds. We could easily tell the difference from before the sway bar and after. Thanks



by:

1 of the best purchased I've made for my Fleetwood Discovery. All wandering is now gone. Took an afternoon to install (I'm a retired mechanic) and am very pleased with the outcome. I also purchased an Steering Stabilizer Shock a year before and I improved wandering maybe %25. Both purchases arrived (in Alaska) promptly and in good condition. I Will purchase from eTrailer.com again when needed.



by:

I love this sway bar, and love the service and overall experience with etrailer. My F350 came with factory sway bars front and rear, and I'd replaced the rear bar several years ago, and was impressed with the difference it made. So, more recently I ordered the front bar to replace the smaller factory unit, and it again made a wonderful change for the better. Our Bigfoot truck camper is tall and heavy, but our rig handles wonderfully and has essentially no sway or rock in traffic or on bumpy roads. I highly recommend this sway bar.



by:

After a year of usage, I couldn't be happier with the Roadmaster front and rear anti-sway bar kits. The rear kit for my W22 chassy, the mounting hardward would not fit properly. I call Roadmaster directly and they custom built the mounts, painted, and shipped within days.



by:

Grate stuff. Easy to bolt up and figure out. Drive quality improved dramatically and less sway with trailers.
Just in the kit with the grease and red lock tight the hardware washers were one size to large so I got the right ones and installed all is well.



by:

Easy installation ,done by myself laying on my back in the driveway only took about 1 1/2 hours to do. I have a lift but didn't use it and I think it was easier on the ground for just one person. Sway bar made a big difference in the drivability of my 2003 E350 pleasure way class B
I'll upgrade the front factory bar to the HD Roadmaster bar soon
If you have issues with the handling of your Ford pleasure way start with this sway bar



by:

This is a must have for your Motorhome. What a difference in the ride of the coach through the highway washes, the side winds and the side drift of the big rigs. This bar reduces the coach movement by as much as 80% I would say. The installation is easy for someone who is mechanically inclined and still doable for DYIer as long as you have the tools ( standard 1/2” drive tool set, low speed high torque drill for the holes in the frame and a 250 plus ftlbs torque wrench). I would highly recommend this Anti-Sway Bar.



by:

a quick fix it to install sway bars front and rear.
I did this and just came home from 2400 mile trip.
installed rear only before we left, then at our destination installed front.
the drive back it handles wayyy better and it sits level now.
""your results may very-use at your own risk. ""
from etrailer.com
rear = RoadMaster 1259-109.
front = RoadMaster RM-1259-105 with RM-590063-00 bracket kit.
i'm sure over time they will flex and stress and start to lien again.
But for now it looks much happier. ( and level )
and i'm very happier with performance and drivability
Seems the big bars help distribute the load to both sides,
you can drive it with one hand now.
and when a truck passes, it's very manageable.
( this could be part the tires on it )
these can be installed in about 6 hours pretty easy.
The hardest thing is drilling the 8 holes in frame. ( 4 front 4 rear. )
We had to shift 2 brake lines over via and small bracket and covers lines with old fuel like to act as wear buffer.



by:

Great instructions and nice, high quality fasteners.
Fitment was great and only minor adjustments to my Air lift air bags was needed.
I have a 2013 Ram 3500 Dually with:
-Torklift 30K hitch
-5” Exhaust
-Air lift 7500XL air bags.
The lower brackets for the air bags needed to be moved slightly and I had to cut the excess bolt off on the passenger side.



by:

Received the product in a timely manner. The shipping company used I’d give a no star rating. I received the anti-sway bar bare out of a box or wrapper with the installation part box and a cut out piece of cardboard with the shipping label on it taped to the bare bar with about five yards of packing tape. The bar was scuffed, scratched and chipped with the RoadMaster label destroyed. I realize it’s going to be installed under the front of my motorhome but as much as it costed I would like to be the one to scratch and scuff it. If I was a company installing this on a customers vehicle I’d return it. I do not believe it was shipped from etrailer in this condition.



by:

Great buying experience with ETrailer. Fast shipping and quality constructed part. Noticeable difference in controlling body sway. Very pleased with the bar and highly recommend Etrailer.



by:

I have carried a truck camper for 7 years with just Timbrin blocks also from Etrailer and finally made the move to Roadmaster anti sway bars front and rear. Planning a trip to the west coast from Georgia next year and wanted all the help I can get for stability on the mountain roads. Have yet to test but Im sure it will be a noticeable improvement. When my wife takes the wheel so I can have a break she would see-saw the steering wheel to balance the load and it drove me insane. Hoping for relief for both of us.



by:

RM-1109-121 Rear Sway bar for 85 Chevyvan G30 RV. Install was pretty straightforward. I would mount the brackets to the frame first and then the sway bar to the axle. It’s easier to drill the holes without the sway bar getting in the way.
Before I replaced the shocks and upgraded the from sway bar and added the rear sway bar my G30 Chevyvan Winnebago was a wallow wagon. It took 110% focus to drive. Now it drives like a regular vehicle. Smooth. No leaning over when cornering. It’s night and day.



by:

2 hr easy install myself. Need the front to go with it...


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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Wilson B
Updated by:
Wilson B
Employee Andy C
Installed by:
Andy C
Employee Sabrina W
Written by:
Sabrina W

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