What Causes Trailer Sway?

Posted by ProPride Hitch on 17th Dec 2020

What Causes Trailer Sway?

Trailer sway is caused by a trailer moving behind a vehicle. It can be unpredictable and incredibly unsafe. 

When the sway becomes excessive, it can lead to fishtailing or whipping, creating a dangerous situation for the passengers in your vehicle and other motorists on the road. According to multiple reports, trailer sway is responsible for more than 500,000 accidents every year. 

They're not always fatal, but they almost always cause significant damage.

You're probably wondering what causes trailer sway -- you know, it's when your trailer moves back-and-forth on the road. The side-to-side motion of a vehicle in-tow is caused when the side forces on the trailer cause it to move in a different direction than the vehicle.

One of the main things you need to do in order to avoid trailer sway is making adjustments to your hitch when connecting it to your trailer. It is important to remember that it is possible for a trailer to sway slightly when behind any vehicle because the way the hitch impacts the center of gravity between the two vehicles. Learn more about How Much Trailer Sway is Normal in this article.

You should understand what trailer sway is to ensure you know what to look for when inspecting the different components of your towing system. Always take time to confirm your trailer sway bar setup is in good operating condition before towing your trailer. You should also know how trailer sway bars work to make sure you understand how to attach yours properly.

Create a checklist to use every time you hook up your trailer to help avoid trailer sway while on the road. Having a checklist will ensure you do not make simple mistakes like forgetting to put in the hitch pin or putting one of the breakaway cables in the wrong place.

Other things that may cause trailer sway include the following items:

  • Human error when attaching the trailer to the hitch.
  • Weight that is not properly distributed.
  • A defective hitch or locking system.
  • Missing or damaged components for your hitching system.

Besides equipment problems, sway can also be caused by issues that are encountered while on the road. These include the speed at which your vehicle is traveling while on the road and by naturally occurring things like wind conditions.

The U.S. Department of Agriculture “Safe Trailering” program advises to reduce your speeds by 25 percent when hauling a trailer behind a vehicle. When hauling a trailer, you should observe the speed limits posted for trucks rather than regular motor vehicles. Typically, you should not accelerate beyond a speed of 55 miles per hour when you have any type of trailer attached to your vehicle. Most swaying occurs when vehicles are traveling at higher speeds.Things like your speed are especially important once on the road because as USDA reported, driver error is the top cause of trailer crashes. Therefore, you should always be mindful of what is happening on the road around you.

Excessive speed while hauling a trailer is a factor that can be controlled by a driver. However, there are several other factors that are beyond the control of the driver while on the road. For instance, wind can have a major impact on how your trailer handles while you are driving.

When hauling a camper trailer, speed can be impacted by wind conditions from drafts of passing vehicles, crosswinds and natural wind when descending a hill. A study by Knott Laboratory which looked at commercial towing accidents found that crosswinds can have be a significant force on moving vehicle leading to increased force pushing on the side of a trailer.

The National Highway Traffic Safety Administration (NHTSA) recommends releasing the accelerator pedal to slow down when these types of air pressure changes occur from a passing vehicle. They also recommend having the steering wheel in a firm grip to help keep the vehicle stable.

If you are the one passing a vehicle, in order to avoid trailer sway, always pass on level ground. It is also important to avoid passing on narrow roads or soft shoulders. Finally, check to see that there is enough room for your trailer to clear the vehicle you are passing.

Additionally, the NHTSA recommends several general handling tips to avoid sway while pulling a trailer.

  • Avoiding sudden stops and fast starts.
  • Slowing down when traveling over bumpy roads including railroad tracks.
  • Making wider turns so the wheels on your trailer do not hit or ride up on a curb.

As an experienced RVer you will learn the feel for your vehicle and trailer. While on the road you will figure out how to make the needed adjustments to minimize the impact of trailer sway while driving. You will start to anticipate when you need to slow down or lightly press down on your brakes. In addition, as a responsible driver, you will be able to make the choice of when you need to stay off the road because of unfavorable conditions.

The type of hitch you use for your vehicle is also important to consider when looking at what causes trailer sway. In recent years, several advancements have been made in trailer sway control hitches to provide better safety for you while on the road. Some level of trailer sway is inevitable, however choosing the right hitch for your vehicle can help minimize these hazards.

By following speed laws and doing proper inspection of your vehicle you can usually avoid excessive trailer sway while on the road. Trailer sway can lead to dangerous situations and can put passengers in the vehicle at risk. When towing a trailer behind you remember the items outlined in this article that may impact trailer sway on your vehicle.

At ProPride, we offer the 3P hitch -- the most advanced trailer sway control hitch on the market. We want to keep you and your family safe on the road by avoiding dangerous trailer sway. Contact us today for more information regarding our 3P hitch. ProPride will offer you excellent customer experience and is ready to take care of all your towing needs!