What Is the Difference Between Trailer Weight Distribution & Sway Control
When it comes to bumper pull hitches weight distribution is not the same as sway control but the two features often go hand in hand.
Many weight distribution hitches will have built-in sway control but a stand alone sway control bar cannot distribute weight.
In this article, I’m going to go into detail about what each term means and what kind of hitch you should get for your bumper pull trailer or RV travel trailer.
Related Product: Use a wireless Tire Pressure Monitoring System (click to view on Amazon) to monitor the pressure in your trailer’s tires and be warned of flats.
What Is Weight Distribution?
Like the name states, a weight distribution hitch distributes the weight of a trailer.
It does this to help the weight of the entire trailer be more evenly placed on both the tow vehicle and on the trailer.
This makes towing much safer and smoother when driving down the road.
In fact, weight distribution hitches are required if your tongue pull trailer is a certain weight compared to the tow vehicle you are using and most RV travel trailers are required to have a weight distribution hitch no matter how heavy they are.
How Weight Distribution Hitches Work
When you hitch a heavy trailer to your vehicle you’ve probably noticed that the back of the vehicle sags down quite a bit when the entire load is put onto the hitch.
When you tow a trailer like this the front of the tow vehicle is lifted and you don’t have as much control when driving down the road.
This “squat” as it’s called is one of the main causes of trailer sway, which is one of the biggest reasons for trailer related accidents.
A weight distribution hitch will use two steel arms that stick out from below the ball of the hitch and attach to the tongue of the trailer.
25% of the tongue weight is then distributed to the front axels of the tow vehicle and another 25% is moved to the back axels of the trailer.
It lifts up the back of the tow vehicle and the front of the trailer so they are more even and there’s less sag.
Note that this does not technically reduce the trailer’s tongue weight and you should never use a hitch that isn’t rated for the entire tongue weight of the trailer you are towing.
When the entire tow vehicle and trailer are both sitting level from front to back you know the weight has been properly distributed.
Towing will be smoother, there will be decreased wear on the back axle and bearings of your tow vehicle, and it’s also safer because you have more control.
If you are still experiencing a lot of sag on the back of your tow vehicle you can also use airbags to lift it more for even better, safer towing.
How The Different Weight Distribution Hitches Look
There are three kinds of weight distribution hitches.
Here’s a look at each kind, the advantages, and disadvantages of each.
Weight Distributions Hitches That Use Chains
The first kind uses steel arms and chains, like the Curt Round Bar Weight Distribution Hitch (click to view on Amazon).
Note that this version is weight distribution only and does not come with a sway control bar. If you want both you will need this version by Curt (click to view on Amazon).
This style of weight distribution hitch is often more affordable than the other styles and it’s quieter when driving. But in order to get sway control, a separate sway control bar has to be installed which requires you to drill holes into the frame of your trailer’s A-frame (tongue) and you also have to unhook it when reversing.
It’s also very heavy to lift up the arms to support the weight of the trailer. Curt makes a handle (click to view on Amazon) for this style of hitch that makes it easier to lift and hook up.
Weight Distribution Hitches That Use Steel Tabs & “L” Pins
The second main style of trailer weight distribution hitch is designed with integrated sway control.
Instead of using chains, it connects the steel arms directly to the tongue by using steel tabs that the arms lift onto. Like the Equalizer Sway Control Hitch linked to below.
This style of weight distribution hitch is easy to install and does a great job of controlling sway because of the strong triangle shape it incorporates.
You don’t need to drill any holes in the frame of the trailer like you do with the chain style and you can back your trailer without having to unhook anything.
The only downside to it is the metal on metal screeching noise it can make when the trailer turns.
Like the other trailer weight distribution hitch I talked about above the steel arms are very heavy to lift up and onto the tabs.
You can get a special handle (click to view on Amazon) that looks like a bar with a hook on the end to help lift the weight distribution arms onto the steel tabs mounted to the frame.
Chain Vs Steel Tab (2 & 4 Point) Weight Distribution Hitches
Both of these styles are very popular and they each have their pros and cons.
Neither is better than the other at distributing weight but the second tab style is slightly better at controlling trailer sway than the kind that uses the sway bar.
The main downside to both of them is you have to lift the steel arms up manually, it’s a good idea to get a leverage bar for them.
See Also: What Is The Best RV Stabilizer System?
The Anderson Hitches New Weight Distribution Hitch
There is a third style of weight distribution hitch which is new to the RV world.
The Andersen Hitches No Sway Weight Distribution Hitch. It’s becoming the next big thing for bumper-pull trailer weight distribution hitches with sway control.
It uses heavy-duty springs, a turning ball hitch, and two chains to not only distribute weight but to reduce trailer sway as well.
The best thing about it is doesn’t require any heavy lifting like the other styles do all you need is a socket wrench to turn the tension bolt a few times.
And there are no heavy steel arms to store and carry around, just two chains which weigh hardly anything in comparison.
It’s also very quiet when towing and you don’t have to unhook it before backing.
There are two companies that make Hensley style hitches. They were designed by a man named Jim Hensley who started one company then moved to another.
The first design is called the Hensley Arrow and the second is called the ProPride P3.
I’m going to focus on the ProPride P3 since that’s the more advanced design for sway control and weight distribution.
This beast of a travel trailer hitch is the heaviest and most advanced of all the bumper pull hitches on the market today.
It has a lot of parts and seems complicated at first, but once installed it’s one of the easiest hitches to hook up to and set up.
The biggest difference between a Hensley hitch and a standard sway control hitch is that there is no ball.
According to ProPride the ball hitch is where trailer sway starts, so they eliminate that by removing the ball completely.
Instead, a large coupler is attached to the ball receiver on the front tip of the trailer.
This is the part that also uses two heavy duty arms that can swing side to side to work with the natural movement of the trailer to keep it centered without pulling around the tow vehicle.
Installed on the back of that coupler are heavy duty arms, also called the yolk.
This part locks in the coupler and also pushes the pivot point from the tip of the trailer to the rear axle of the tow vehicle.
An adjustable hitch bar is inserted into the hitch receiver of the tow vehicle. This is the part that will stay on your tow vehicle.
The cool thing about the hitch bar is it creates more distance between the tip of the travel trailer and the vehicle. This allows you to open the tailgate even when the trailer is hitched up.
Traditional travel trailer hitches do not allow enough space to open the tailgate.
When you hitch up the ProPride the hitch bar needs to be inserted into the coupler.
It looks like it might be difficult to do since you need to get a square bar into a square hole but since the couple can swing side to side hitching up is actually easier with the Hensley ProPride P3 than with a regular ball hitch.
Now for the weight distribution part of this Hensley style travel trailer hitch.
Instead of removing the bars to unhitch they actually stay connected to the trailer at all times.
Jacks that are installed onto the A-frame of the trailer raise and lower the arms into the loaded position for driving. Or the relaxed unload position for camping.
Instead of having to use a pry bar to load the weight distribution arms you can use a socket wrench or drill to move the jacks up or down.
One downside to ProPride P3 is the weight. It weighs almost 200 lbs. That adds a lot to the tongue weight of your travel trailer.
Make sure the hitch and tow capacity of your tow vehicle can handle the added tongue weight.
I recommend checking out some videos of the ProPride P3 Hensley hitch to see it in action so you can understand how it works better.
When Do I Need To Use A Weight Distribution Hitch?
Weight distribution hitches are actually required by truck manufacturers when the trailer reaches a certain weight compared to the size of the tow vehicle.
Half-ton trucks and SUVs are normally required to use a weight distribution hitch when the trailer is 5,000 lbs and heavier.
Heavy-duty trucks like 3/4 ton and 1-ton trucks usually require a weight distribution hitch when the bumper pull trailer is 6,000-8,500 lbs.
Also pretty much all bumper pull RV travel trailers require a weight distribution hitch.
Even small single-axle trailers that weigh only 500 lbs like the Forest River R-Pod are recommended to have a weight distribution hitch with sway control.
Remember that a weight distribution hitch is for you and your bumper pull trailer’s safety. It’s always a good idea to use one even if you are below the weight requirements.
What Is Sway Control?
When towing any kind of bumper pull trailer down the road it’s connected to your vehicle with a single ball hitch that lets it move freely for turns.
This can also be a problem because there’s no real force to stop your trailer from swaying around behind your vehicle.
If the back end of the trailer starts to swing side to side it can be very dangerous because the force of the trailer could cause you to go off the road. Some severe cases of trailer sway even cause the entire trailer to flip.
It’s something that should be avoided, and weight distribution hitches with sway control are a great way to help stop trailer sway.
How Sway Bars & Hitches Work
Things like road conditions, wind, speed, tire pressure, tongue weight, the number of axels your trailer has, and even the placement of cargo inside all contribute to trailer sway.
A sway control bar or hitch uses friction to keep your trailer centered behind your tow vehicle.
If the back end tries to start swaying the friction bar acts as a side to side brake. It puts up enough resistance to stop your trailer from turning on its own and it will keep it centered behind your vehicle in most cases.
A sway bar and distribution hitch will help with trailer sway but you should still be careful how you pack your trailer.
Putting more weight in the front helps reduce sway and driving slow during high winds is advisable.
Even with a high tech sway bar or anti-sway hitch trailer sway can still happen.
If you ever start to feel your trailer swaying the most important thing to remember is not to brake, take your foot off the gas and slow down slowly.
For detailed instructions on what to do when a trailer starts to sway and more information on what causes it, check out this post here.
How Sway Control Bars & Hitches Look
A sway control bar is an affordable way to reduce trailer sway and it’s a good idea to have on all trailers, especially single axel ones.
You can use a sway bar without having to use a weight distribution hitch, but if you are required to use a weight distribution hitch you should always have some sort of sway control as well.
Sway Control Bars
Sway control bars like the EAZ LIFT Screw-On Sway Control (click to view on Amazon) are bolted onto the tongue of a bumper pull trailer near the ball hitch coupler.
Once you’ve hitched up to your trailer you attach the end of the sway control bar to a small ball next to the tow vehicle’s main ball hitch.
You then tighten the sway bar so there is the proper amount of tension to stop sway.
The main downside to this kind of sway control is you have to unhook it before you back your trailer and it isn’t as effective as the integrated sway control weight distribution hitches.
A lot of times when you purchase a weight distribution hitch that doesn’t have integrated sway control, like the chain style, it will come with a sway bar like the EAZ Lift Sway Control Bar.
Weight Distribution Hitches with Built-In Sway Control
If you don’t like the idea of drilling holes into your frame or you want something more effective, you can get weight distribution hitches with sway control integrated like the Equal-i-zer 4-point Sway Control Hitch (click to view on Amazon).
The friction is created by the steel arms rubbing on the steel tabs. The tongue weight of the trailer is pressing down and it makes for a very effective, but fairly noisy sway control.
There’s also the Anderson Hitches No Sway Weight Distribution Hitch (Click to view on Amazon) that I talked about before which has integrated sway control and weight distribution.
It uses springs to put tension on the side to side motion of the trailer but you can still turn and back with it attached.
If you have a heavy trailer and you travel a lot I would suggest getting a weight distribution hitch with the integrated sway control. It’s more effective and you don’t have to disconnect anything before backing.
When Do I Need To Use Sway Control?
Honestly, every bump pull trailer no matter how small or large should have an anti-sway device on it.
Whether it’s a simple sway bar or a full-on weight distribution hitch with sway control it’s always better to be safe than sorry.
Frequently Asked Questions About Weight Distribution & Sway Control
Do 5th-wheels need weight distribution and sway control hitches?
One of the best things about 5th-wheels and gooseneck trailers is how smooth and easy they are to back and tow.
The weight of a 5th-wheel trailer is placed over the center of a truck and the weight is automatically distributed over both axels evenly.
Because of this, there is hardly any risk for sway and you have more control over the trailer.
That being said there is a sort of weight distribution 5th-wheel hitch for short bed trucks.
The hitch works by putting the weight of the trailer in the center of the truck bed while you tow.
When it’s time to reverse and maneuver, the hitch slides back to put more room between the truck cab and the front of the trailer.
This allows you to do sharp turns when backing but also tow the trailer in the correct, safe position.
Check out all the best 5th-wheel hitches for all styles of truck beds in this article here.
What Do I Do When A Trailer Starts To Sway?
No matter how many precautions you take trailer sway can happen to anyone towing any size of bumper pull trailer.
It’s important to know what to do if your trailer starts to sway, especially at high speeds.
I’ve written a detailed article about the 5 things you need to do when a trailer starts to sway, click here to check it out.
Do all weight distribution hitches that use chains also need a sway control bar?
Most weight distribution hitches that use chains to hold the steel arms up instead of tabs do require a sway control bar in order to be effective against sway.
There has to be the friction aspect in order to keep the trailer centered behind your tow vehicle.
That being said the new Anderson Hitches No Sway Weight Distribution Hitch (click to view on Amazon) is one of the only weight distribution with sway control bumper pull hitches that use chains to both distribute weight and control trailer sway.
How do I make it easier to lift the steel arms up on my weight distribution hitch?
If you have a weight distribution hitch you are probably no stranger to the chore it is to lift the arms or chains up and into place.
You can use lever handles like the ones I talked about earlier in this article but it still can be very difficult to get even the handles into position to be lifted.
One quick trick you can do is hitch up the trailer like normal and when it comes time to put the weight distribution hitch into place use the tongue jack to lift the trailer a few inches.
Doing this levels out the truck and trailer and puts it into the even position it is supposed to be in after putting on the distribution hitch.
This makes it much easier to set up the arms. Once everything is in place you can take down the trailer jack and you are good to go.
Can I back my trailer into a tight spot with a weight distribution hitch on?
Most weight distribution hitches allow the trailer to be backed into place without having to be taken off.
It’s the sway control bar that has issues with backing into tight turns.
If you have a sway control bar it’s recommended to disengage it before reversing and tight maneuvering.
What size of weight distribution hitch do I need for my truck & trailer?
You always want to get a weight distribution hitch that is rated for more pounds than your trailer is rated to weigh.
I’ve written more information about that in the frequently asked questions section of this article about the best weight distribution hitches.
What Is Trailer Stability Assist (TSA)?
Some vehicle manufacturers use a program often called trailer stability assist to help control trailer sway using sensors and the vehicle’s computer.
When it starts to sense trailer sway the TSA system will engage and automatically use braking to stop the sway.
This is a cool feature that is great for towing with small vehicles and light trailers but for heavy trailers sway control bars and weight distribution hitches are still required.
Have any more questions about weight distribution, sway control, and their differences? Leave a comment below.