To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.
Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.
Error submitting comment. Please try again momentarily.
Big vehicles tend to sway when winds hit or when you change lanes fast. The 1-1/2" diameter Roadmaster rear anti-sway bar links the rear axle to the frame so the weight stays balanced through turns and lane changes. The result is a steady, level ride that tracks straight even when wind or passing traffic tries to push you around.
When you turn sharply or hit uneven pavement, the bar uses the rear axle as a brace to counter the body’s tendency to roll. That keeps the vehicle flatter and more predictable so you can maneuver smoothly without fighting side-to-side motion. You’ll feel the difference in every turn—less lean, quicker response, and a calmer ride.
This isn’t mild steel. The 4140 chromoly alloy is much stronger than the standard 1020 steel used in most bars. That extra strength makes it nearly 30% better at resisting sway. Polyurethane bushings replace the typical rubber versions, standing up to oil, gasoline, and ozone without breaking down. Less flex means more consistent support and a solid feel that holds up for years.
The kit includes all the heavy-duty hardware, clear instructions, and bushing lubricant you need. It bolts to the axle and frame without drilling into the frame, and it’s designed to work around most popular aftermarket setups like airbag systems. Once installed, it works on its own or together with a front bar for an even more planted ride.
Constant corrections on the wheel can wear you out fast. By cutting out the side-to-side sway, this bar helps the vehicle track straight and respond predictably. Long highway runs feel calmer, steering feels steadier, and you arrive without the usual tension from fighting the road.
Customer Satisfaction Score:
92% were satisfied with this product
8% of customers were not satisfied
Ratings & Reviews
Only thing that kept the product from 5 stars is that it was missing the 2- 2” x 5/8” grade 8 bolts.
Easy step by step instructions.
There were nuts and bolts missing and the instruction are hard tho understand.
I have always loved etrailer but this last order was not up to their standards. Directions were not the best for my 2021 GMC 2500HD and wrong parts. The 6 bolts for mounting the main brackets were 3.5" and 4.5" is what is needed and no nuts for them. The directions left out that you had to drop the gas tank to attach the drivers side bracket also and link arm bolts are not the same size. It has cost me $xx in nuts & Bolts so far.
Sierra K.
9/15/2021
I am sorry that you are having such trouble with this product. It sounds like something is not correct in the order. Customer Service will be reaching out to you.
Durability
Was easy to install and worjz awsome made a big difference in the truck should make a big difference with towing 5 th wheel. But will have wait until spring for that
Easy to install and really noticed a difference with truck camper on
Fairly Easy to Install, Improved the handling especially when towing my 5th wheel camper
Very good results, helps a lot with side to side sway. Instructions said to remove shocks to install but I was able to work around that. Front supports seem to be a bit lower than I expected but so far no consequences.
I put this unit on a 2020 GMC Denali. It fit perfect. Only took an hour to install. I carry a 12 foot overhead Lance camper and this bar took almost all of the top sway out when coming out of a parking lot or when big rigs pass.
We purchased a sway bar from etrailer.com. We installed it and are happy with the results. It made a difference in the way our truck rides.
This made a huge difference in towing my truck camper. It was easy to install even though I had to install and remove and reinstall it. I did not drop the tank instead fished the hardware through a hole on the outside of the frame. the only thing I do not like is how low this hangs. any ground clearance is lost. noticeable on fire roads or logging roads.
Very happy with how the truck handles both loaded and unloaded around corners and in windy conditions. I had to be a little creative not to move the fuel tank in order to install the driver side, but install is straightforward. I should’ve got a second pair of hands to help me though.
I just installed it yesterday. I lost the nut welded to the piece of wire in the frame on the right side and spen the next 45 minutes trying to retrieve it or get it flipped over the right way. On the left side I tied a long leader on the end just in case. Of course that part was fine. But I supported the gas tank under the strap and had to move to get the strap back in place. After drilling out the bolt holes in the shock mounts I had to figure out of the bolts went from the bottom like the diagram or from the top like the picture. I haven't driven yet but im sure it will be great.
Have a 5th wheel trailer and bought a slide in pickup camper. When I was looking for the camper,alot of sights recommended installing a rear sway bar. So I did. When I picked up the camper had a 360 degree on ramp that I knew would be the test,at 30 mph truck did not lean at all. Very impressed! Good product. Noticed less lean with 5th wheel when backing on an angle.
Super rugged bar, relatively simple installation, but the instructions could stand to be a little better. A few more pictures would go a long way towards making it easier to understand.
Ajr
11/20/2022
Great! Hualing a truck camper around for the last 8 months or so and the sway bar makes that a much nicer operation.
Decent product, fast shipping if the product is in stock but very poor execution.
If you buy this you'll need to plan on a couple trips to the hardware store. As several other reviews from the past couple years state, there are no grade 8 5/8" 2" bolts included in the kit. I thought that since the issue had been called out in other reviews, the problem would have been fixed by now which made me even more frustrated when I received the incomplete kit. I've got a 2022 GMC Sierra 2500 and I had to drill out the shock mounts, this made the 7/16" bolts too short so add those to your list if you have a similar truck.
Additionally the directions appear to be good at first glance but have some big gaps when you're actually trying to do the install. This is the only kit I've gotten from etrailer I've had issues with missing parts and poor directions.
Etrailer's picture of the product is incorrect as the frame mounts actually included with this kit are much less substantial than shown. It is only the u shaped piece with one bolt through them keeping the front end of the sway bar up. Furthermore that bolt is attached to a nut that is welded in a plate (welding a nut reduces its strength) so the whole front end is attached to two compromised nuts. I would not have purchased the kit if I had known that to start with, I thought I was getting what was in the picture for this product.
Lastly if you also have the superspring suspension kit it makes it very hard to get the shock mounts bolted to the frame bracket. I ended up having to remove that and reinstall it after the sway bar was in place.
I reached out to customer support before writing this review and the issue was not solved.
David A.
12/28/2024
The sway bar has held up ok. After a year of heavy use I have had to disassemble it 1 time to tighten the a 2 bolt that came loose from the frame. I noticed it from a loud clunking noise.
Very excited and happy to have purchased this sway bar for my 2021 GMC Sierra 3500HD. The quality is superb with it's thick heavy bars. Came with everything needed to install this behemoth!
There was one hiccup while installing, at no fault to etrailer. The holes to fit the screws into my truck next to my shock absorbers had nuts welded on the top of the holes?! The screws were to big to fit through because of these nuts. Only way to get around it was using a reamer bit to make the hole even all the way through. From there it was easy. The instructions even indicated that there could be some manufacturing alterations from the original specs that may effect install. Highly recommend!!
Installation was pretty easy. Would be nice if the plate with the nut you have to fish down the frame was just a flat plate with a threaded hole - hard to get it down there with the nut on top. If the holes on the shock mount have a welded nut, you have to drill it out, which was easy but then the bolts are 1/4" short to get all they way into the nylock nut so I had to go buy 4 more 7/16 grade 8 bolts that were 1/2" longer. Initial test ride unloaded and not much noticed in ride quality. Actually seems smoother. I bought this for when I load 3000+ lb truck camper to help with side/side sway. Will update this when I test it.
Installed on 2023 GMC Sierra 3500HD. Almost 1/2 price of Hellwig and 1/4" bigger diameter and it is also chromoly. Maybe a little harder to install because of the plate you have to fish down the frame (especially the drivers side because the rear tank strap has to be unbolted and tank supported with a jack stand then jacked back up to be re-bolted - add an hour for install) and only one hole instead of 3 on the end so no adjustment. Not sure if that adjustment makes much difference.
Made a great improvement hauling my travel trailer, even on windy days
Info for this part was:
At etrailer we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time.
Brooke M.
7/21/2025
Gosh, I am so sorry to hear that! Let me look into this and make sure you get the missing pieces!