What Does a Motorhome Rear Trac Bar Do?
What Does a Motorhome Rear Trac Bar Do?
If driving your motorhome feels like a constant battle with the steering wheel, you’re probably wondering what’s actually causing it.
One motorhome owner described the experience as feeling like being on a seesaw while sitting in the back of the coach. Another compared driving their motorhome to being on a water bed: no matter how fast or slow they were going, they felt all over the road. There can be different things contributing to a motorhome that wanders or feels unstable. But one possible source of the problem is unwanted side-to-side movement at the rear axle.
That’s where a rear trac bar comes in.
Below, we’re answering some common questions about rear trac bars, what they control, how they work, and how they differ from an RV sway bar.
What is a rear trac bar?
An RV rear trac bar is an aftermarket upgrade designed to control unwanted side-to-side movement between the rear axle and the frame of a motorhome. You may have heard this type of movement described as “tail wagging the dog.” On certain motorhome chassis equipped with a rear leaf spring suspension, the rear axle can have some side-to-side movement in relation to the frame. That movement underneath the coach can turn into something you actually feel behind the wheel. The rear of the coach moves, you correct at the steering wheel, and then you’re correcting again.
Why am I constantly correcting the steering in my motorhome?
Unwanted rear axle movement could be part of the problem. When the rear axle moves side to side relative to the frame, that movement can be felt while driving. The rear of the motorhome moves, the driver makes a steering correction, and the process can repeat. Add wind or passing trucks, and you may find yourself making even more steering corrections.
How does a rear trac bar work on a motorhome?
A rear trac bar connects the rear axle to the frame and helps keep the axle centered underneath the coach. The suspension can still move up and down normally, but the trac bar helps prevent unwanted lateral—or side-to-side—movement. Reducing that movement at the rear axle can also reduce the amount of correcting you have to do at the steering wheel. The goal is a motorhome that tracks straighter and feels more stable and predictable going down the road.
What is “tail wagging the dog”?
“Tail wagging the dog” or "tail wag" is a term used to describe the side-to-side movement between the rear axle and the frame. That movement underneath the motorhome can translate into movement the driver feels behind the wheel. This is also where it can get confusing because RV owners may simply describe what they’re experiencing as “sway.” But not every type of movement is the same, and different parts are designed to control different types of movement.
Is an RV trac bar the same as a sway bar?
No. A trac bar and a sway bar are not the same thing. A sway bar primarily helps control body roll, or the leaning and rocking of the coach. A trac bar controls side-to-side movement between the axle and the frame.
That distinction is important.
Even though you might use the word “sway” to describe what your motorhome is doing, figuring out what is actually moving can help determine what type of upgrade the coach needs.
Can a rear trac bar improve motorhome handling?
If unwanted rear axle movement is contributing to the handling problem, reducing that movement can reduce the amount of steering correction required from the driver.
One customer who had a rear trac bar installed described the difference after the work was completed:
“On this last test drive, after all the work was done, it was like night and day.”
They said they could still feel a bump in the road, but the coach would immediately right itself rather than continuing with the back-and-forth motion they had experienced before. Another customer described their experience after having a rear trac bar installed by saying the coach was going “nice and straight” and “just floating.”
What makes SuperSteer rear trac bars different?
At Henderson’s Line-Up, we were seeing a need for better aftermarket solutions to the motorhome handling problems coming through our shop. That’s why we have our SuperSteer division: to develop and offer solutions for those problems when the right option isn’t already available. Rear trac bars are one of those solutions. There aren’t a lot of companies offering rear trac bars specifically for motorhome applications. SuperSteer rear trac bars are designed for specific motorhome applications to control unwanted lateral rear axle movement and give motorhome owners another option for addressing this type of handling problem.
Does every motorhome need a rear trac bar?
No.
A motorhome that wanders or feels unstable can have different things contributing to the problem. A rear trac bar isn’t automatically the answer for every coach or every RV handling complaint. But if unwanted rear axle movement is part of the problem, a rear trac bar might be the solution. That’s also why identifying the movement you’re actually experiencing matters. Is the coach leaning and rocking? Is there unwanted movement between the axle and frame? Are you constantly making steering corrections?
Understanding the problem comes before choosing the upgrade.
Some motorhomes, such as those with rear air suspension, already have a rear trac bar from the factory. In this case adding another one is not necessary, but if you are experiencing the issues talked about above you may want to inspect the factory rear trac bar and make sure it is functioning correctly.
Need Help With Your Motorhome?
If you’re interested in SuperSteer Trac Bars or want to learn more about the products we offer, visit supersteerparts.com or give us a call at (888)898-3281. If you’re dealing with a steering, suspension, or handling problem and aren’t sure where to start, our team at Henderson’s Line-Up is here to help. Visit hendersonslineup.com or call us at (541)479-2882 to learn more.
Thank you for reading this blog and until next time we wish you safer and happier driving.
Published: September 2026
About the Author:
Tommy Henderson is the third-generation CEO of Henderson’s Line-Up and holds a degree in engineering. Growing up in the family business, Tommy has spent his career around RV steering, suspension, alignment, and handling. Today, he continues Henderson’s Line-Up’s hands-on approach to solving RV handling problems while helping develop solutions through SuperSteer, the parts and product division of Henderson’s Line-Up.