Methods for Trailer Sway Control

There are a few simple, practical things you can do to reduce the risk of trailer sway

When you’re traveling down the road hauling a travel trailer or a fifth-wheel or any other kind of open/enclosed trailer, various weights factor into your towing experience and, more importantly, your safety and the safety of everyone traveling the roads with you. One of these is tongue weight.

In an earlier post entitled What Is Tongue Weight and Why Is It Important? I discussed how tongue weight impacts the operation of the tow vehicle and the trailer. Improper tongue weight can have very serious consequences including trailer sway.

In today’s post, I’m looking straight at trailer sway—what is it, how to prevent it, and how to control it when it happens. I’ll also include some general towing tips while we’re on the subject.

This is important information for anyone who tows anything (even a flat-bed trailer or utility trailer), so let’s dig in and get started.

Camping in a trailer on Padre Island National Seashore, Texas © Rex Vogel, all rights reserved

What is trailer sway?

Trailer sway is the side-to-side motion of a trailer that can happen when you reach a certain speed as you’re towing a trailer of any type or size. As you might imagine, it’s extremely uncomfortable to be towing a trailer that’s swaying from side to side.

However, what makes trailer sway so dangerous is that it can build to the point of whipping which is a more violent tossing back-and-forth of the trailer that can quickly become uncontrollable.

Generally speaking, this type of side-to-side motion occurs when a trailer is improperly loaded and is heavier in the back than in the front.

Let’s take a look at the best methods for preventing trailer sway.

Driving Utah Scenic Byway 12 © Rex Vogel, all rights reserved

Methods for preventing trailer sway

Fortunately, there are a number of ways to prevent trailer sway, all of which are easy to apply for any driver. The only requirement is to be conscientious in your planning and towing.

Load your trailer properly for trailer sway control

Perhaps the greatest contributor to trailer sway is an improperly loaded trailer. A trailer that’s loaded too heavily in the rear of the trailer will be prone to trailer sway from the get-go.

So, one of the top tips to prevent trailer sway is to be sure to load 60 percent of your cargo weight in the front half of the trailer box. This is one of the most important actions you can take to prevent trailer sway. Just be sure that you don’t exceed your tow vehicle’s and hitch’s tongue weight.

Camping at Alamo Lake State Park, Arizona © Rex Vogel, all rights reserved

Load all cargo inside the trailer

By this, we mean that you should always load your cargo so that none of your load extends outside the trailer.

Don’t allow any cargo to stick out of the rear of the trailer, for example, or to extend outside the trailer body in any way. That cargo will move the center of gravity of the trailer further backward increasing the likelihood that sway will be a problem.

This is more applicable to utility/box trailers but be aware of it even with RVs.

Never exceed your trailer’s maximum gross weight

Your trailer is rated with a maximum gross weight (GVWR or Gross Vehicle Weight Rating) with good reason. Adhere to the boundaries of that rating without fail.

Never exceed the maximum gross weight rating of your trailer.

Never overload your tow vehicle

Likewise, never overload the vehicle you’re using to tow your trailer. This can be easy to do. Many people use their tow vehicle to haul lots of stuff—extra clothing, recreational and sports-related items, extra food, etc. It’s amazing what people will try to use their tow vehicle to carry.

Overloading your tow vehicle is a sure way to invite sway and potentially whipping which could be disastrous.

Driving La Sal Mountain Loop Road, Utah © Rex Vogel, all rights reserved

Maintain a maximum speed of 55 mph

When towing a trailer of any type, it’s best (imperative, really) to maintain a maximum speed of 55 mph if you want to prevent trailer sway.

Rest assured that you won’t arrive at your destination much more quickly if you’re driving 65 or 75—or at least not quickly enough to be worth the risk that speed over 55 mph carries.

When towing a trailer, always maintain a speed of 55 mph or less.

Invest in a sway control kit

You can also invest in a sway control kit appropriate to the trailer you intend to tow. These help to limit lateral trailer motion, thus reducing sway.

These kits usually include the sway control unit and appropriate attachment pieces.

The sway control unit attaches to your vehicle and to the trailer at the coupling point and is designed to counter any wandering/sway.

Note that TWO sway control units are recommended for use with larger trailers.

Camping at Sunshine RV Park, Texarkana, Arkansas © Rex Vogel, all rights reserved

Invest in a weight distribution hitch/sway control hitch

While a weight-distribution hitch is NOT a reliable trailer-sway prevention method on its own, it can be effective when combined with a sway control unit. In fact, there are packages that combine a weight-distribution hitch with sway controls.

It should be noted that weight distribution hitches and sway control kits are not intended to be the sole means of controlling trailer sway. You’ll still need to employ operational methods of preventing trailer sway such as proper trailer loading, proper speed (55 mph or lower), and proper weight management.

Sway control kits and weight distribution hitches are intended to provide additional assistance with sway control on winding roads and windy days.

Just be aware that not all hitch receivers are compatible with weight-distributing hitches. Check with your manufacturer before purchasing.

Trailer at Wind Creek Casino RV Park, Atmore, Alabama © Rex Vogel, all rights reserved

Methods for controlling trailer sway (once it happens)

Let’s look specifically at methods you can use to control trailer sway when it’s occurring.

Remove foot from gas pedal

First, remove your foot from the gas pedal. While your instincts may move your foot to the brake pedal, don’t apply the brakes. Simply remove your foot from the gas pedal and allow your vehicle to slow down on its own.

Camping at La Paz County Park, Arizona © Rex Vogel, all rights reserved

Do not apply brakes

Again, don’t apply the brakes though once your speed has decreased from removing your foot from the accelerator, you can very gently apply your trailer brakes manually if you have them.

However, don’t apply your tow vehicle brakes.

Gradually reduce speed to control trailer sway

Gradually reduce your speed to at least 10 mph less than the speed at which you were traveling when the swaying began.

Do not increase speed

Do NOT increase your speed. Higher speeds make trailer sway more severe leading to whipping and an inability to control the trailer. This presents a very dangerous situation.

Camping at Gulf State Park, Alabama © Rex Vogel, all rights reserved

Maintain steering wheel in straight position

Don’t try to steer out of the sway. It won’t work and is very likely to make matters worse.

Instead, try to keep your steering wheel in a straight position at 12 o’clock and don’t make any sudden turns.

Stop and reload trailer

As soon as you’re able to safely do so, stop and reload your trailer moving the heavier portion of your cargo to the front of the trailer.

When you resume travel, be sure to keep your speed at or below 55 mph.

General Towing Tips

Anytime you’re towing anything, these general towing tips will keep you safer.

Camping at River Run RV Park, Bakersfield, California © Rex Vogel, all rights reserved

Slow down

When towing a trailer, always reduce your normal driving speeds. Your combined vehicle size and weight are increased when you’re towing so going slower will help to ensure you can maintain control.

When going downhill, never ride brakes

Never ride your brakes when traveling downhill. Instead, slow down and shift into a lower gear allowing your engine/transmission to help keep your speed down.

Camping at Whispering Hills RV Park, Georgetown, Kentucky © Rex Vogel, all rights reserved

When going uphill, shift into lower gear and slow down

When traveling uphill, shift into a lower gear and slow down. Stay in the slow lane, turn your flashers on if you’re driving below the speed limit (or below 45 mph on the highway) and keep an eye on your temperature gauge.

If engine temperature rises, exit the roadway as soon as safely possible

If your engine’s temperature rises, exit the roadway as soon as you can safely do so. If your engine’s temperature increases too much, your vehicle will stall leaving you stranded in traffic and possibly damaging your engine.

Slow down

As I close out this post on methods for trailer sway control, this one is well worth repeating. When you’re towing a trailer, slow down for everything including curves, inclement weather, road construction, and prior to exits.

SLOW DOWN is the mantra of safer trailer towing.

Worth Pondering…

Speed was high

Weather was hot

Tires were thin

X marks the spot

—Burma Shave sign

What Is Tongue Weight and Why Is It Important?

One of the most important things you can do to keep your family and yourself safe while towing a trailer is making sure you know the various weights and weight limitations associated with your rig

When you’re traveling down the road hauling a travel trailer or a fifth-wheel or any other kind of open/enclosed trailer, various weights factor into your towing experience and, more importantly, your safety and the safety of everyone traveling the roads with you. Many people are well aware of what terms like GVWR (gross vehicle weight rating), dry weight, and tow capacity mean but the meaning of factors like tongue weight is not as well understood.

So, what is tongue weight and how might it impact your travel?

In today’s post I’ll answer those questions and more as we investigate the term tongue weight and the reason why it’s so critical to understand. If you ever plan to tow a trailer you’ll want to pay close attention because in order to tow safely, you’ll need to understand this important topic.

Fifth-wheel trailers at Rain Shadow RV Park neat Clarkdale, Arizona © Rex Vogel, all rights reserved

What is tongue weight?

Tongue weight is a term related to towing. Sometimes denoted as TW, it’s defined as the downward force that the tongue of a trailer applies to the hitch of the tow vehicle. In other words, the force the trailer tongue exerts on the hitch ball.

Improper tongue weight can be the difference between a safe towing experience and a very dangerous one.

The trailer is like a lever and the axle of the trailer is the pivot point (or fulcrum) for that lever. If too much or too little weight is applied to the tongue of the trailer, a dangerous situation can result (more on that in a minute). Tongue weight can’t be too heavy and it can’t be too light. It has to be just about right—balanced—like the weights of a couple of people on a seesaw at the playground.

Travel trailers at Creek Fire RV Resort, Savannah, Georgia © Rex Vogel, all rights reserved

Is tongue weight the same as hitch weight?

Yes. The terms tongue weight and hitch weight are interchangeable as both refer to the force a trailer exerts on a hitch.

Sometimes the term pin weight is used instead of either of the other terms but while pin weight refers to the very same concept it’s usually used in reference to fifth-wheel trailers specifically.

>> Related article: The Pros and Cons of Buying a Travel Trailer

Regardless, all three terms refer to the downward force the trailer/fifth-wheel applies to the hitch on the vehicle towing it.

Travel trailer at Whispering Hills RV Park, Georgetown, Kentucky © Rex Vogel, all rights reserved

How do you calculate tongue weight?

To calculate tongue weight you’ll take the weight of your tow vehicle alone and subtract it from the weight of your tow vehicle with the trailer attached. 

Weight of tow vehicle while trailer is connected–tow vehicle’s weight=tongue weight

If the result of your calculation is within the proper tongue weight range for your loaded trailer and the capacity of your hitch and tow vehicle, then your setup is properly balanced. If not, some adjustments need to be made.

At the end of this post, I’ll describe a few different ways to check the weight of your trailer’s tongue.

Trailers and a tow vehicle at A+ Motel and RV Park, Sulphur, Louisiana © Rex Vogel, all rights reserved

What is proper tongue weight?

Proper tongue weight for a trailer with a ball-mounted hitch is between 10 and 15 percent of the Gross Towing Weight of the trailer.

For example, the proper tongue weight for a trailer that weighs 1,000 pounds would be somewhere between 100 and 150 pounds.

Using a real-weight scenario if a 3,000-pound trailer is loaded with 1,000 pounds of cargo, the proper tongue weight of the loaded trailer should be somewhere between 400 and 600 pounds (between 10 percent and 15 percent of the 4,000 pound total).

There are some complexities to navigate here, however. For instance, fifth-wheel or gooseneck trailers are designed to handle significantly larger loads so proper TW for these trailers is generally agreed to be between 15 and 30 percent of the total loaded trailer weight.

Fifth-wheel trailer at Hacienda RV Resort, Las Cruces, New Mexico © Rex Vogel, all rights reserved

What happens if tongue weight is too heavy?

If the tongue is too heavy, the tow vehicle’s steering will be impacted. Traveling ahead of its axis, a too-heavy trailer tongue will also affect the way the trailer moves along the road and the way it stops.

When TW is too heavy, stress is placed on the frame, suspension, tires, drivetrain, or brakes of the vehicle being used to tow. Because of the excessive weight transferred through the hitch ball, the rear tires of the tow vehicle can become overloaded, pushing the rear end of the vehicle around.

>> Related article: RV Weight Distribution Tips for Packing your RV

A too-heavy tongue weight may also negatively impact vehicle handling especially when rounding curves and taking corners. This is due to the fact that the front of the tow vehicle is being lifted up, reducing the weight on the front tires and thus their grip and steering effectiveness. Moreover, the vehicle’s stopping distance may be impacted such that you’re unable to stop fast enough after depressing the brake pedal.

These are very dangerous situations owed to improper tongue weight. Fortunately, tongue weight can be adjusted relatively easily. If you’ve ever seen the rear of a vehicle in a low position while towing, what you were likely seeing was an improperly loaded trailer resulting in excessive tongue loading. In such a case, the load in the trailer would need to be adjusted so that more of the weight was moved toward the back, behind the trailer’s axle.

Trailers at Columbia River RV Park, Portland, Oregon © Rex Vogel, all rights reserved

What happens if tongue weight is too light?

If there is insufficient weight on a trailer tongue, the trailer may be difficult to control and may sway from side to side. If the tongue is too light, cargo needs to be moved forward of the trailer’s axle.

What happens with a too-light tongue weight is that the tongue of the trailer isn’t exerting sufficient downward force on the tow vehicle’s hitch ball. This leads to trailer sway, a very dangerous situation that puts the trailer at risk of slipping off the ball and disconnecting from the tow vehicle.

Fifth-wheel trailer at Edisto Beach State Park, South Carolina © Rex Vogel, all rights reserved

How to check your tongue weight?

There are a few different ways to check.

>> Related article: Meet the RVs: The Towables

The first method requires you to drive to a public scale or weigh station and follow these steps:

  • Load your trailer and the vehicle you’ll be towing it with exactly as they’ll be loaded for an upcoming trip (including food, fuel, water, and propane)
  • Drive onto the scale at the weigh station making sure all four wheels of the tow vehicle are on the scale while also making sure the wheels of the trailer are NOT on the scale
  • Make a note of the weight of the tow vehicle
  • Without moving the vehicle(s), unhook the trailer and jack up the trailer tongue so that there is no weight on the hitch ball
  • Make a note of the weight of the tow vehicle only (this is your GVW or gross vehicle weight of the tow vehicle)
  • Subtract the GVW from the weight of the tow vehicle with the trailer attached (this is your tongue weight)

The second way to check is to use a trailer tongue weight scale.

A scale with a 5,000-pound capacity would be appropriate for most fifth-wheels and goosenecks). Scales are also available with 1,000 and 2,000-pound capacities.

If you expect your tongue weight to be less than 300 pounds, you can use a bathroom scale. To do this, you’ll place the tongue or jack directly on the bathroom scale (or, you can place a small piece of plywood on the scale to protect it).

If you anticipate that the weight may be more than 300 pounds, you can use a special arrangement of boards and pipes to reduce the amount of weight being placed on the bathroom scale, multiplying it appropriately to calculate the actual weight. That method, complete with instructions and diagrams can be found on the Curt Manufacturing website.

Travel trailer at Cedar Pass Campground, Badlands National Park, South Dakota © Rex Vogel, all rights reserved

Why is tongue weight so important?

As I’ve noted throughout this article, tongue weight impacts the operation of the tow vehicle and the trailer. Improper tongue weight can have very serious consequences.

In the case of too much, the rear tires of the tow vehicle can be overloaded resulting in the rear end of the vehicle being out of control and reducing the tow vehicle’s ability to both steer and stop.

>> Related article: 6 Great Tips for RV Beginners

In the case of too little, extremely dangerous trailer sway can result even to the extent of the trailer being moved off the ball and disconnecting from the tow vehicle. This could easily lead to a horrible accident involving not only damage to your trailer but injury and loss of life.

So, tongue weight is extremely important—and fortunately, also easily adjusted.

Worth Pondering…

Speed was high

Weather was hot

Tires were thin

X marks the spot

—Burma Shave sign