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  1. Anti-Sway Bars
  2. Roadmaster
  3. Anti-Sway Bar
  4. Rear
  5. 1-3/4 Inch Diameter
  6. Mounting Hardware Included
THIS ITEM IS NOT A FIT FOR
1999 Lexus GS 400
Roadmaster

Roadmaster Rear Anti-Sway Bar - 1-3/4" Diameter

Part Number: RM23ZR
In Stock
$1,650.00
Retail:$1,835.24
You Save: $185.24
Anti-Sway Bars
Not Confirmed to Fit

1999 Lexus GS 400

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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 RM23ZR or order online at etrailer.com. Free expert support on all Roadmaster products. Great prices and Fastest Shipping for Roadmaster Rear Anti-Sway Bar - 1-3/4" Diameter. Anti-Sway Bars reviews from real customers.
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  • Reviews (2491)
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Roadmaster Anti-Sway Bars - RM23ZR

Highlights

  • Custom Fit for Your Vehicle: Tuned to your suspension for better control and stability.
  • Reduces Sway: 1-3/4" chromoly steel bar minimizes side-to-side movement for a steadier ride.
  • Handles Crosswinds: Keeps your rig level against gusts, passing traffic, and shifting cargo loads.
  • Less Driver Fatigue: Cuts constant steering corrections so long trips feel smoother and more comfortable.
  • Improves Cornering: Balances weight transfer in turns so handling feels stable and predictable.
  • Uses Existing Mounts: Bolts to rear axle and frame with included heavy-gauge hardware—no drilling needed.
Made in USA

Features to know about

More Control on the Road: 1-3/4" Rear Bar Reduces Body Roll

Nothing makes driving feel more stable than cutting out the side-to-side sway that knocks you around in turns or gusty wind. This 1-3/4" diameter Roadmaster rear anti-sway bar mounts to the rear axle and frame to balance weight transfer and reduce lean. Built from thick 4140 chromoly steel, it provides a stronger brace than standard 1020 steel, increasing roll stiffness and keeping your rig level through corners, lane changes, and uneven pavement.

Roadmaster rear anti-sway bar installed on vehicle rear axle showing connection to chassis and suspension.

Less Effort at the Wheel: Stable, Predictable Highway Handling

Crosswinds, passing traffic, and shifting loads can make long drives exhausting. By linking the chassis to the rear axle, this bar steadies the frame and minimizes the constant steering corrections that wear you out. The result is steadier tracking and a more relaxed drive, even on windy stretches or rough highways.

Durable Construction: 4140 Chromoly Steel with Polyurethane Bushings

Strength and longevity come from the details. The 4140 chromoly bar resists flex and twist far better than softer steels, keeping its shape and performance over time. Polyurethane bushings replace standard rubber, holding up against oil, gasoline, and ozone. They don’t squish out or deteriorate, so you get consistent support and a solid, responsive feel mile after mile.

Close-up of Roadmaster anti-sway bar polyurethane bushings and grommets showing durable construction and mounting hardware.

Straightforward Installation: Mounting Hardware and Lube Included

With no drilling required, this anti-sway bar bolts directly to existing points on the rear axle and frame. Heavy-gauge mounting hardware, detailed instructions, and bushing lubricant are included for an easy bolt-on install. Once in place, it works seamlessly with most suspension upgrades and aftermarket accessories for a balanced, confident ride.

Specs

Dimensions

  • Bar diameter: 1-3/4"

Warranty

  • Limited lifetime warranty

1139-211 Road Master Anti-Sway Bar - Rear

Installation Details RM23ZR Installation instructions

This Product Fits The Following Vehicles




Video of Roadmaster Rear Anti-Sway Bar - 1-3/4" 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 Manufacturer Breakdown - Roadmaster Anti- Sway Options

Hello neighbors, it's Brad here from Etrailer and today, I'm with Jeff from Roadmaster. And today, we're taking a look at what you can do to your coach to enhance the suspension. So a lot of coaches out there, real top heavy feeling and people think, "Well, it is what it is. It's a big bus, you know, how do I improve this" But that's not necessarily the case. Roadmaster has a few different options to help make a better ride, overall. Definitely, it definitely does.

So typically, we educate our customer to let 'em know that yes, you can improve your ride or you can get that GT version suspension with your motor home. And how we do is we basically have to find out what's the root of the problem, okay. So typically, when a customer comes up to us, the very first thing they say is, "Hey, I'm constantly doing this when I'm going down the road." That that just means so many different things. So we actually ask a few more questions. "Hey, do you tow a vehicle behind your motor home Does it get worse when you put that motor home behind, or that vehicle behind the motor home And when it does, is this getting worse as well" And when the answer is yes, yes and yes, then we kind of know that the issue is tail wag at that point.

And that's usually fixed by a product called a track bar. And what it does, it just locks the rear axle in place. So it's not moving side-to-side. It's only moving straight up and down like it should, okay Or the next thing that I typically ask my customers is, is "Whenever you go in and out of turns, does it feel like the coach wants to roll over to its side" Most of the time, the answer is yes. And typically, the reason why is because when that coach or when the chassis was manufactured, they really had no Earthly idea what the final output was gonna be, how tall it was, how much weight was gonna be on it.

So you actually took center of gravity from probably a foot and a half, to a foot off the ground and all of a sudden, you're six feet off the ground or eight feet off the ground. We're putting air conditioners, solar panels, satellite dishes, everything else on top of these things. And we just need to drastically improve that. So how we do that in this case, is we upgrade the sway bars. In some cases, we're doing a remove and replace.

In other cases, we're actually piggybacking, adding a second sway bar to the rear or to the front of the coach. So sway bars are something predominantly, you see on passenger vehicles. And when I started working here, putting a sway bar on an RV, I go, "Well, I mean it's the same concept, why not" But seeing the difference, I've done sway bars on my own personal vehicle and the first turn you take, you go, "Oh, that's a lot better." Definitely. It's no different on an RV, in fact, it might even be. Jeff Much more noticeable. Yeah, absolutely, 'cause. Or before driving, it does feel like it's gonna topple over and you don't necessarily get sports car handling, but it's more response on the steering, it's more direct and you just feel a little bit more planted, more, honestly, confidence when driving. Yeah, and a lot of our customers are reporting back up, you know, they're saying up to a 60% increase in how they feel that their coaches is handling. And that's what we really like to hear and that's where we're trying to aim for. We wanna give that customer their vacation the minute they start out of the driveway and not once they get to their destination. Yeah, and so as far as sway bars, there's rear sway bars as well as front sway bars, correct Correct. So why would someone choose one or the other or should they go with both Typically, we suggest both. In some cases, yes, you can start off with the rear, but like I said, again, we like to suggest both because we're actually tuning the bars for the weight of that vehicle that it's gonna carry. So to have an upgraded bar in the rear and not one on the front, kind of does it a little bit of injustice. That's fair. Now something else too, as a long drive that's gonna wear you out is, is fighting the steering wheel back and forth and you guys have a way to fix that, correct Absolutely, we sure do. So once we turn and look at all the issues that the customer has, we determine what the issues are, we start talking to the customer and we resolve 'em by doing track bars, sway bars, the last and final thing that we usually recommend is a steering control. So basically, what the steering control does and essentially, is put center force pressure on a tie rod. So that way we're trying to hold that vehicle in a straight line. So if the customer has road ruts, if they turn around and hit potholes in the road, high winds, it's an assistance for that customer to keep in a straight line on their coach. Yeah, and that's, again, one of the installs, many of the installs that I've done is the steering stabilizer. And again, that's one of those, "Does it really make that big of a difference" Well, just going through our parking lot and cutting it, you let go of the steering wheel and it kind of still just tracks that way, whereas the steering stabilizer, you can see the steering wheel go back to center and then, when you're just going down a straight line, it just feels like it's in a nice natural groove. Jeff Yeah, sure does. So it's definitely a lot more comfortable, especially, you know, putting a lot of hours on the road or doing any twisty-turvy, you know, curvy roads out there, it's just gonna help balance it and kind of counter steer a little bit for you, bringing it back to center. That way, you're not having to fight that wheel back and forth. Now with both of, you know, our front sway bar, rear sway bar as well as the steering stabilizer, that's gonna get you a really good ride. And I think overall, better drivability, these also still work in conjunction with other suspension enhancements that you can add on as well, so you can really deck out the suspension of your RV. And I think it's. You'll be a believer once you start doing these, you're just gonna enjoy driving it more, I believe. Exactly, it brings the vacation back and the fun back into RV-ing. Yep, absolutely. Well, this was a look at some of the Roadmaster suspension components to just get your coach going down the road a little bit safer and a little bit more comfortable. Thank you Jeff from Roadmaster, for taking the time to break that down for us. All right, thank you.

Customer Satisfaction Score:

Ratings & Reviews

4.8

2491 reviews
5 Stars
(2136)
4 Stars
(244)
3 Stars
(47)
2 Stars
(22)
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 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:

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:

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:

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:

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:

Easy to install by myself in the driveway. I replaced both the front and rear anti-sway bars and the improved handling characteristics were noticeable immediately. Fantastic product!



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:

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:

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:

After waiting 3 weeks the swaybar kit was drop-shipped from the factory. Received and discovered the bushing inserts were the wrong size (too small) for the bolts that were sent. Contacted Roadmaster support and provided them a photo and invoice as requested. The replacement inserts were approved and shipped out. I got metric bolts to go with the inserts I received. I will save the replacements for additional replacements.
The install was fairly straight forward.
Haven't had a chance to tow the 5th-wheel yet.



by:

The anti sway bar is a big improvement when the truck bed camper is on. The installation took a bit longer than expected because the frame brackets don’t fit around an aftermarket B&W gooseneck hitch. I had to fabricate new top brackets and drill out the bottom brackets to widen the bolt pattern. Keep this in mind if you have a gooseneck hitch.



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:

Excellent high quality product made a big difference in handling with heavy Artic Fox camper
Give poor rating regarding installation instructions



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:


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

  • Sway Bar Options To Reduce Sway And Body Roll On 2016 Thor FourWinds 35SK RV F550 Chassis
    Hey Scott, they are correct. Upgrading the front and rear sway bars will certainly help keep your Thor Four Winds Class C RV straight on the road while reducing sway. You will notice a lot less body roll on turns too! For the best of the best, I'd go with Roadmaster Rear Anti-Sway Bar - 1-3/4" Diameter # RM23ZR and Roadmaster Front Anti-Sway Bar - 1-3/4" Diameter # RM33BQ. While they are a little pricey, they are the beefiest and biggest options for your setup. For a second best setup...
    view full answer...
  • Sway Bars And Sumo Springs For 2024 Omni Class C Motorhome On Ford F550 Diesel Chassis
    Hello Bill, thanks for reaching out. Adding front and rear sway bars to your 2024 Omni Class C Motorhome will help a lot with stability, sway and overall ride quality. Sadly, Roadmaster does not offer a steering stabilizer for your vehicle, but we do have sway bars and sumo springs. Here is what I recommend for the Ford F550 Diesel chassis: - Roadmaster Front Anti-Sway Bar - 1-3/4" Diameter # RM35VR - Roadmaster Rear Anti-Sway Bar - 1-3/4" Diameter # RM23ZR - SumoSprings Solo Custom...
    view full answer...
  • Recommended Sway Bars and Steering Stabilizer for a 2022 Thor Magnitude XG32 Motorhome on a F550
    I've got you covered Ruth! There are quite a few options out there. I checked with Roadmaster and to add sway bars front and rear and a steering stabilizer to your 2022 Thor Magnitude XG32 Motorhome you will need the following parts: Front Sway-Bar - Roadmaster Front Anti-Sway Bar - 1-3/4" Diameter item # RM35VR Rear Sway-Bar - Roadmaster Rear Anti-Sway Bar - 1-3/4" Diameter item # RM23ZR Steering Stabilizer - Roadmaster Reflex Steering Stabilizer with Mounting Brackets for Class C Motor...
    view full answer...
  • Recommended Rear Sway Bar for a 2024 Ford F-550 Cab and Chassis
    Hey Simon. The Roadmaster Rear Anti-Sway Bar item # RM-1139-190 and item # RM22FR are both currently in stock(02-25-2026). They fit a 2024 Ford F-550 cab and chassis with an emergency vehicle body. So unless you're driving an ambulance you'll most likely need the Roadmaster item # RM23ZR, which is also in stock. The Roadmaster item # RM23ZR is a 1-3/4" sway bar that is designed to fit a class C motorhome built on a 2024 Ford F-550 cab and chassis. This setup comes with all mounting hardware...
    view full answer...

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Info for this part was:

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

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