Why is my car swaying on the highway?

Why Does My RV Sway So Much on the Interstate?

There’s nothing better than looking in your mirror and seeing the beauty of the landscapes behind you. On the other hand, looking in those same mirrors and seeing your RV swaying back and forth can be a nightmare for you and those driving behind you on the interstate.

Today we want to take a closer look at what might cause your RV to sway so much on the interstate and how you can help minimize it.

Let’s get started!

What Is RV Sway?

RV sway is exactly what its name implies. It’s when your RV sways back and forth on its own as you’re traveling down the highway – like a dog wagging its tail. It can cause some serious issues for you and other drivers while you’re traveling.

Ideally, you’ll be familiar with the idea of trailer sway, so you know how to respond when you experience it. Overreacting when you experience side-to-side motion can escalate the situation quickly.

What Causes RV Sway?

Trailer sway is often the result of improperly loading your RV. Putting too much weight in the rear increases the chances that you experience trailer sway. However, even a properly loaded trailer can still experience swaying.

Driving at excessive speeds or crosswinds can also cause a swaying motion. It’s a good idea to keep an eye on the weather and your speed when towing.

Why Driving on the Interstate Increases RV Sway

RV sway often occurs the faster you’re driving. Interstates typically have some of the highest speed limits across the country. This is why you’re more likely to experience RV sway while on an interstate than on any other road. Combine the high rate of speed with the open road, and it’s the perfect storm to experience sway with your RV.

Just because the speed limit is over 70 mph doesn’t mean that you should be driving that fast. Most RVers will typically keep their maximum speed somewhere between 55 to 65 mph.

This helps reduce the chances of swaying and provides optimal fuel consumption.

How to Keep Your RV From Swaying

If you want to avoid experiencing RV sway while towing, there are some things you can do. Let’s take a look!

Distribute Weight Correctly

One of the best things to avoid sway in your RV is by distributing the weight correctly. You typically want to keep 60% of the weight in your RV in front of the front axles. This helps avoid the rear of the RV being too heavy, which often causes sway.

If you’re often experiencing swaying in your RV, you might look at what the distribution of weight is like in your RV.

If you are towing a toy hauler or using a bumper-mounted cargo rack, you might have too much weight behind the axles of your RV. Try moving some of the heavy objects into the rear of your tow vehicle in front of the axles. Doing so can greatly improve your towing experience and eliminate the sway.

Correcting Your RV Sway on the Interstate

You can do some things to correct your RV sway while on the interstate. First of all, keep an eye on the weather. This helps you avoid putting you and your RV on an interstate on a windy day.

Depending on your rig, you may start to feel the wind pushing you around and cause the RV to sway once it hits 12 mph to 15 mph. Most RVers will find a place to park anytime the winds are over 25 mph. The sway becomes too much to battle, and correcting the sway becomes very difficult.

If you experience RV sway when it’s not windy, pull over and make sure you’re loading your RV correctly. You don’t want to have too much weight on the rear of your RV.

If you are loading it correctly, you might need to check the alignment of your axles. Slowing down and using sway bars are great ways to correct RV sway while on the interstate.

Take Care of RV Sway

RV sway can be very serious and could cause you to overreact and cause an accident. You must be in control of your RV at all times. If you are having regular issues with RV sway, you need to figure out why as soon as possible.

Whether you need to redistribute the weight in your trailer or add a weight-distribution hitch to your setup, fixing RV sway isn’t always that difficult. You may need to make some adjustments to your setup, but it’s typically pretty straightforward.

Have you ever experienced RV sway while towing?

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Trailer Towing Tips: How to Prevent Trailer Sway

There are few things more frightening while towing your recreational vehicle than trailer sway. A sudden gust, a passing semi-truck or a quick steering correction can start your trailer swaying or fishtailing. The loss of control can mean tipping your valuable recreational vehicle or causing a serious accident.

Even the most experienced drivers have lost control of their towed trailers with disastrous results. A brief encounter with sway on the highway can quickly put a damper on your vacation and make you think about putting the camper back in the garage or up for sale. These tips can help you understand what causes trailer sway, as well as help keep your RV upright.

What causes trailer sway?

Below are common causes of trailer sway when towing a trailer.

Hitch adjustments

Any trailer towed with a hitch set behind the rear axle of the tow vehicle can sway or fishtail while driving. The hitch acts as a pivot point in-between the centers of gravity of the two vehicles. Any trailer sway or side-to-side force will turn the vehicle and create an unexpected steering force.

If that sideways force is strong enough it can be more powerful than the road-tire friction for the drive wheels on the vehicle. This can cause the tipping over or separation of the trailer and maybe even the truck or car too.

Wind and drafts

Trailer sway can be a result of crosswinds, drafts from passing semi-trucks or descending hills using incorrect braking technique, according to Mark Polk in his RV Tech Tips series on RVTravel.com.

The front of trailers are aerodynamic to improve towing gas mileage, but the sides aren’t. A 35-mph crosswind could put as much as 3,440 pounds of force pushing on the side of a large trailer, according to a study on commercial vehicle towing accidents by Knott Laboratory in 2009.

Weight distribution and balance

Loading too much gear on one side of your camper can also cause an unbalance, making them swing more dramatically once a sway starts, like a pendulum around its center of gravity. This can also make your RV more likely to suffer a blowout, or additional braking and steering problems.

Balancing weight to the forward and rear is also vital for controlled driving. Between 12-15% of the trailer’s weight should be resting on the tow vehicle’s hitch, according to Bill Estes, writing in Trailer Life Magazine. Any less weight forward may pull up on the tow vehicle’s rear wheels just when you need more traction and control. However, drivers have to be careful not to exceed the tow rating of the hitch or vehicle itself.

How to prevent trailer sway

The best way to correct trailer sway is to avoid it in the first place. Follow these general tips when towing from the National Highway Traffic Safety Administration (NHTSA)[1]:

Use the manufacturer recommended gear when towing.
Slow down. Moderate driving speeds produce less strain on your vehicle and trailer reducing the chance for trailer sway.
Don’t make any sudden steering maneuvers.
Check the tire pressure. Under-inflated tires reduce the load-carrying capacity of your vehicle or trailer which can cause sway.

Several hitch designs claim to reduce sway through friction control or weight distribution. Friction based hitches create a rigid connection, limiting sway but still allowing the trailer to turn. Weight distribution hitches use special parts to distribute the tongue weight of the trailer among all of the axles, both tow vehicle and trailer[2].

How to control trailer sway

If your trailer starts to sway on the road, the NHTSA recommends activating the manual brake control override by hand. Applying the tow vehicle brakes will generally make the sway worse.

Lift your foot from the accelerator but don’t step on the brake pedal unless you’re in danger of hitting something.
Keep a firm grip on the steering wheel to control sway caused by large passing vehicles.
Find a safe place to park and check for proper weight balance and hitch adjustment.

Hooking up and towing a trailer or camper might not seem difficult, but the hitching process can be tough. Learn how to tow a trailer or a camper.

Find out how to prevent trailer sway and how to control it.

Use manufacturer recommended gear Use the manufacturer recommended gear when towing.
Slow down Moderate driving speeds produce less strain on your vehicle and trailer reducing the chance for trailer sway.
Avoid sudden turns Don’t make any sudden steering maneuvers.
Check tire pressure Under-inflated tires reduce the load-carrying capacity of your vehicle or trailer which can cause sway.
Control trailer sway To control trailer sway, lift your foot from the accelerator but don’t step on the brake pedal unless you’re in danger of hitting something. Keep a firm grip on the steering wheel, and find a safe place to park and check for proper weight balance and hitch adjustment.

An Insight Into Car Swaying Side To Side [Updated]

The diagnosis of a car swaying side to side relates to the malfunction of a certain suspension component.

You will quickly recognize the vehicle’s instability and uneven tread wear once your car feels like its swaying. More particularly, you can hear some weird noises.

This informative post explains what happens inside the suspension system and the root causes of the above signs. Let’s get started.

Why Is My Car Swaying Side To Side?

Major causes of cars swaying side to side are broken sway bars, worn springs and shocks, worn silent blocks or bushings, faulty steering rod end and ball sockets, and wheel alignment.

By clarifying the functionality of the components mentioned above, this post provides you with the foundational knowledge to understand the root causes deeply.

1. Broken Sway Bars

The sway bar is a stabilizer sway bar, anti-sway, or anti-roll bar. This U-shaped bar is connected to the ends of an axle. Its duty is to maintain the vehicle’s stiffness.

To understand why broken sway bars stay on the top list of car swaying side to side at high speeds, let’s go along with us to understand its purpose and method of operation.

Once the vehicle steers to corners aggressively on twisty roads, the anti-sway applies a force to the opposite side of the vehicle to create centrifugal force, which prevents the car from rolling.

This centrifugal force is applied to each wheel’s suspension to minimize body rolls.

Also, the anti-roll bar forces all sides of the vehicle to the same height once the vehicle goes around sharp turns, bumps, or curves.

In a fast turn, the vehicle’s force tends to go to the outside wheels and compresses the suspension on the outside wheels. The other two wheels inside the turn will rise, or the suspension will extend.

Once the vehicle steers around corners, the stabilizer sway bar also pushes down the tires inside the turn and distributes the vehicle’s weight over four tires.

The working principle of the sway bars pinpoints their duty in controlling the vehicle’s stability.

Therefore once noticing that the car sways side to side when driving, you should prioritize diagnosing the sway bars.

2. Worn Springs And Shocks

Worn springs and shocks are among the major causes of swaying. These parts enhance the vehicle’s stability and control the driver’s brake, turn, accelerate, or run on rough roads.

The springs support the vehicle’s weight by loads carried. If you notice that the car feels like it’s swaying left and right, this may be from worn springs and shocks.

A mechanical visual inspection is vital to determine if springs or shocks are the right culprits. Otherwise, it is easy to confuse with sway bars.

3. Worn Silent Blocks Or Bushings

Being mounted on suspension joints and car steering, bushings are referred to as anti-vibration mountings.

Car control arm bushings, wishbone bushings, A-arm bushings, and sway bar bushings are the most common. These cushions absorb noise and vibration and reduce friction between metal parts of the vehicle.

Over time, bushings get worn out due to cracks from friction, heat, exposure to road dust, excessive loads, or the stress of frequent movements.

Once your car experiences worn bushings, you will quickly recognize road noise and excessive vibration inside the passenger cabin.

In case of worn control-arm bushings, the vehicle’s front end slips out of the subframe position. As a result, it makes you feel that the car sways side to side.

4. Faulty Steering Rod End And Ball Sockets

Steering rod end and ball sockets are related to the vehicle’s motion and stability.

While the tire rod ends transmit force from the steering rack to the wheels and supports steering to maintain its geometry, ball sockets act as pivot points connecting the car wheels to the suspension system.

Ball sockets enhance the smooth and solid movement in the suspension.

According to their functionality, faulty steering rod end and ball sockets are also among the most common culprits that car sways side to side.

5. Wheel Alignment

From the above analysis for “why does my car sway back and forth”, we realize that the car swaying side to side highly relates to the wheel.

Therefore, the faulty wheel alignment could be a potential culprit leading to the wheel swaying from side to side. You can try to redo the wheel settings to see if you can control the car better or not.

What Are The Symptoms Of A Bad Sway Bar?

The most noticeable phenomenon of the malfunctioning sway bar is the rattling noise once you try to go over the bump.

The situation gets worse once that sound still appears on a flat road. You still experience that car sways side to side on the highway.

You also feel the hardness of the tires’ grip on the road, which we can blame for the worn-out sway bar links or the torn bushings.

More importantly, the car feels like it’s swaying left and right due to the failing sway bar. It begins to lose its controlling traction and stability.

FAQs

What Is It Called When The Rear Of a Car Sways Side To Side?

The rear of the car sways side to side, known as fishtailing. The rear wheels lose traction on road surfaces such as icy, flood, and snowy roads.

This phenomenon occurs when you drive too fast or suddenly brake. The vehicle’s rear skidding on the road becomes a scary experience for drivers as their vehicles get shaky and wobbly.

Sometimes, cars turn around or experience tap slapping.

How Do I Know If My Car Needs An Alignment?

The most noticeable symptoms of misalignment are uneven tire wear, noise steering, and squealing tires.

Additionally, the steering wheel is uncentered once you attempt to drive straight. The steering wheel can also be pulled to the right or left side.

What Are The Signs Of A Bad Ball Joint?

The signs of a broken ball joint car can be watched out through vibration, tire wear, squeaking, and clunking noises. It also leads the steering to wander from side to side.

Conclusion

The post of “car swaying side to side” explains why the car feels like its swaying left and right. Through it, we also understand the tight connection between components of the vehicle’s suspension system.

In the situation of car swaying, it is vital for steering and suspension inspection, preceded by a mechanic, to determine the correct diagnosis. So, let’s take your car to a garage for a check-up as soon as you can.

Thank you for reading!