The Importance of Bumper Pull Weight Distribution & Sway Control
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When trying to get the best bumper pull hitch for your vehicle, you’ll see weight distribution and sway control mentioned as features. These are commonly mistaken to be the same thing, but there are important differences that you need to know when buying a hitch.
The features get confused because they often go together. Many hitches that have weight distribution will also have sway control. The opposite isn’t true, however. A sway control hitch cannot distribute weight.
Here, we have explained everything about weight distribution and sway control and answered other pertinent questions about both. We have also included hitches as examples so you can see what they look like and get some product suggestions.
Towing Basics
You’ll need to know the basics of towing to understand weight distribution and sway control mechanics.
First, you need to know the following terms.
- Dry Weight – The weight of a vehicle/trailer that has no fuel, water, cargo, or people in it.
- Unloaded Vehicle Weight – Similar to dry weight, this is the weight of a tow vehicle when it rolls out of the manufacturer’s factory.
- Tongue Weight – The weight that presses down on the hitch ball by the trailer that you are towing. It is often 10% to 20% of GTW.
- Gross Trailer Weight – GTW is Gross Trailer Weight, which is a distinction from Gross Vehicle Weight. It is the total weight of your trailer when it is loaded and ready for the road. Put simply, it is often the maximum weight that your trailer will reach on the road.
- Gross Vehicle Weight Rating – Often abbreviated to GVWR, this is the maximum safe weight that the vehicle should have when out on the road. The manufacturer sets them, so make sure you know the GVWR of your vehicle. GVWR applies to trailers and other towed fixtures, too. You can find the GVWR of your vehicle in the owner’s manual or on the Internet. This greatly affects which vehicle can tow your trailer or fifth wheel, so know this number by heart.
- Gross Axle Weight Rating – This is the highest weight that can safely be placed on one axle of a vehicle, assuming that weight is distributed equally. It also contains the weight of the axle itself. Like the other terms here, it is often abbreviated to become GAWR.
- Gross Combination Weight Rating – The maximum operating weight of a towing vehicle along with the trailer that it is towing. It is essentially a combination of the Gross Vehicle Weight and the Gross Trailer Weight.
Before You Buy a Hitch…
While knowing these weight metrics is important, you’ll need to have the right towing vehicle before you start. Generally, you want a heavier, more powerful vehicle than the trailer or object that you are trying to pull.
This guarantees that the towing vehicle can properly handle the stress you’ll put it under. Fortunately, vehicles are rated for their ability to pull trailers and other hauls, so you should be able to find a suitable vehicle with ease if you haven’t already.
SUVs can tow light and mid-sized hauls. We go into a little more detail on this below.
For heavier hauls, you’ll need to find trucks built for towing. In these cases, a basic hitch is probably too weak for the haul, and you’ll need factory-installed tow packages instead. These built-in hitches change the transmission of the vehicle for towing purposes, a cooling system for the transmission to avoid overheating, and feature electric brake controls for the trailer itself. All of these increase towing capacity.
Lastly, you should try to do all of the following before you try working with weight distribution hitches or sway control bars/hitches:
- Read any relevant literature, typically the owner’s manual, before you begin.
- Make sure you have the tools you need.
- Load your vehicle and the trailer for your trip before you install any hitches.
- For cars that have automatic leveling systems, you should let it take the lead for most hitches. If you’re installing a sway control bar, you may need to disable this feature, as it will get in the way. Car owner’s manuals should detail how to turn features like auto-leveling off.
- Check tire pressure before installing any hitch/bar. Pressure interferes with the heights of your vehicle and trailer, making it harder to fit a hitch since they’ll be at different levels.
Safety Precautions‼️
You should also follow certain safety precautions wherever possible. These will keep you and others safe and, at the very least, avoid potentially costly damages to your vehicles.
Whenever hitching or un-hitching your trailer, you should always follow these steps:
- Use wheel chocks to prevent the wheels from sliding or rolling while you are hitching things up.
- You should apply safety chains to cargo that could become loose on rough terrain or in the event of a crash. When you apply chains, they should be crisscrossed to make them more effective.
- You should always have a pin inserted through the coupler hole before traveling. It should be pushed all the way through, with no risk of it gradually coming undone when vibrating on the road.
- Before traveling, make sure your vehicle’s turning and braking lights work. This is important with any vehicle, of course, but there is more at stake when you are hauling cargo and driving one of the largest vehicles on the road.
- Your breakaway wire, which is a legal requirement for trailers in most places, should always be kept in good condition and secured to your trailer during towing. Without a breakaway cable, you can risk a runaway trailer that detaches and causes harm and damage to others.
- It’s popular to place objects like cinder blocks beneath the tongue of the trailer. If you do that, you should make sure any holes in the block are facing upwards. For surface area, you should place wood on top that can withstand pressure.
Weight Distribution Explained
Weight distribution means that the hitch will spread the weight of a trailer more evenly. It’s a common feature advertised by hitch manufacturers.
When weight is properly distributed between the towing vehicle and the trailer, nothing will break or buckle from bearing the entirety of the trailer’s weight.
Most RV travel trailers need to have one of these hitches no matter how much they weigh.
RV Weight Distribution Hitches & How They Work
To best explain how weight distribution hitches work, you should think back to times when you have connected a heavy trailer to your vehicle.
You may have noticed that the vehicle sags at the back. This is because the entire load is weighing the vehicle down.
If the back of the vehicle is weighed down, the front of the vehicle will be lifted up. It may not be very noticeable, but when you’re driving on the road, this means you can have less control of your vehicle. This, along with sway from the trailer, can cause accidents.
Many trailer-related accidents happen because trailer sway is exacerbated when the weight isn’t balanced properly.
Weight Distribution Hitches Versus Regular Trailer Hitches
Weight distribution models have two steel arms that extend out near the ball of the hitch to reinforce the connection between your vehicle and the tongue of the towed trailer.
Weight-bearing down on the trailer’s tongue can then be spread along the front axle of your vehicle and the back axles of the trailer.
When the weight is spread more evenly, the vehicle and the trailer will become more level, and there will be less sagging. This gives you more control over the towing vehicle while limiting sway in the towed trailer.
It’s important to know that using a weight-distribution hitch doesn’t change tongue weight requirements.
Never use a hitch that isn’t properly rated for the towing job you are trying to give it. The hitch should be able to comfortably shift any weight you put on it, and whether that weight is distributed or not will not affect how much it can handle.
With a level vehicle and trailer, your ride will be smoother, and your vehicle’s back axles won’t wear as much. You should also have more control when driving, too.
Some people still experience sag, even with weight distribution gear, but there are other ways to level out your equipment. One popular alternative is using airbags to lift the trailer up.
The Three Kinds Of Weight Distribution Hitches
There are three main types of weight distribution hitches you’ll find on the market. Let’s take a look at them, along with the advantages and disadvantages that every customer should know.
1. Steel Arms and Chains
First, there are the hitches that make use of steel arms and chains to keep the trailer and the towing vehicle balanced. For an example of what one looks like, check out the Curt Round Bar Weight Distribution Hitch. There is also a no-sway variant too.
- LEVEL TOWING. This weight distribution hitch offers a smoother ride and improved control by distributing the tongue weight of the trailer across the vehicle-trailer combination and leveling the load
These hitches are much more affordable for the average person. They also tend to be quieter when driving. To enable sway control, they need to be modified with a sway control bar that often doesn’t come with the hitch—unless you get a specific model.
You may need to drill holes into the trailer’s tongue, too. Check the instruction manual for detailed directions. As you’d expect, these hitches need to be heavy so that they can bear the weight of whatever you are hitching to your ride.
2. L-Pins and Steel Tabs
Some hitches use so-called L-pins and steel tabs. These have integrated swaying control, so you shouldn’t need to worry about making any modifications to add that feature. You also don’t need to drill any holes, so it’s perfect for those who don’t want to do some DIY work or don’t have the tools.
These models don’t use chains. They use strong steel arms with tabs that connect to the trailer’s tongue.
The Equal-i-zer 4-Point Sway Control Hitch is an example of this. It is easy to install and, due to its triangular shape, is great at controlling sway. If there’s a downside, it’s the scratching noise that comes from metal connecting to metal when you turn your vehicle.
- Our Integrated 4 Point Sway Control provides the highest level of resistance to your trailer's attempts to sway. There is no other hitch on the market that offers as much sway control as the Equal-i-zer.
L-pin hitches aren’t necessarily better than chain models, though having tabs is better at controlling sway with problematic trailers. Both of them require manually lifting steel arms, which may be difficult for some owners.
3. Springs and Chains
Lastly, there are relatively new weight distribution hitches that are being used for RVs and other mobile vehicles. They are great for bumper-pull trailers where weight distribution and sway control are concerned. Through heavy-duty springs, a pair of chains, and a turning ball hitch, they can do everything that chain and L-pin hitches can.
An example of these hitches is the Andersen Hitches No-Sway Weight Distribution Hitch. To properly install one, you only need a socket wrench, which twists the tension bolt several times.
- Unparalleled Sway Control that self-adjusts
It doesn’t require the same heavy lifting that other hitches do. They also don’t have steel arms that need to be carried around, only the chains. They’re also very quiet when compared to the others.
When To Use A Weight Distribution Hitch
So, when is a weight distribution hitch the right tool for the job? As we covered at the start of this page, a weight distribution hitch makes a trailer safer when it is too large and heavy to be towed by the towing vehicle.
In many places, weight distribution hitches are required when the trailer gets heavy enough.
The limit is typically where the trailer reaches 5,000 pounds and over, in which case SUVs and trucks that weigh half a ton need a weight-distribution hitch.
With one-ton trucks, the hitch would be required for trailers that are 6,000 to 8,000 pounds.
A weight distribution hitch is almost always required for bumper-pull RVs. You don’t want your RV or mobile home swaying around, and distributing the weight evenly is a big part of controlling that.
Small-axle trailers still should have weight distribution hitches so it doesn’t sway much and disturb their content.
Many swear by weight distribution hitches simply because they make your rides safer. So, even if you are below any weight requirements, you may want to consider using a weight distribution hitch for safety reasons.
Sway Control Explained
Now that we have some idea of weight distribution, how it works, and when it is required, let’s cover sway control. Although they are often thought to be the same thing, there is a meaningful difference between them.
To understand sway, you need to know how a bumper pull trailer connects to your towing vehicles. With most hitches, it’s a single ball that allows the trailer to move properly when making turns. This movement is good – too much rigidity would make turning impossible. However, too much movement becomes a bad thing.
For example, if the trailer is swinging side to side when you’re driving down a straight road, you have a problem. A swaying trailer can even tip over, destroying the contents and even flipping the towing vehicle in some cases. We’ve probably all seen videos of this floating around on Facebook.
This is something that should be desperately avoided, which is why both weight distribution and sway control hitches are popular and useful for truckers and RVers across the world.
Sway Control Hitches & How They Work
Trailer sway is caused by a variety of factors. Here are just some of them:
- The surface of the road
- The speed of your vehicle
- Your vehicle’s tire pressure
- Current wind speeds
- The number of axles on your trailer
- The tongue weight of your trailer
- Placement of cargo/contents in the trailer
Even the arrangement of weight in the trailer will influence how it moves on the road!
A dedicated sway control hitch (or a sway control bar modification) adds friction to the hitch connection.
This stops the trailer from swaying when it shouldn’t but still allows for turning, so your ride is smoother and easier to control.
When the trailer tries to sway, the bar keeps it centered so it doesn’t disrupt the towing vehicle or pose a danger to anyone.
With trailers, putting most of your weight at the front is advised to further reduce sway. If you pack everything at the back, the back end of the trailer will gather more momentum as it swings from side to side.
It’ll start off small, but with that momentum, it will quickly become a problem. Even the best anti-sway hitches can’t contend with that.
If you ever feel your trailer swaying, you should not suddenly brake.
Instead, you need to slow down gradually so that everything stays under control and you don’t accidentally whip your trailer to one side and cause an accident.
Sway Control Bars & Built-In Sway Control
There are two main ways to achieve sway control. The first is by installing a sway control bar onto your trailer, which works best with a single-axle trailer.
Sway control bars are easily installed by screwing them onto the tongue of bumper-pull trailers. Check out the EAZ LIFT Screw-On Sway Control to see what one of these bars looks like.
- Provides Safer, Easier Towing: Helps minimize sway caused from passing trucks and sudden wind gusts; Adjustable Sway Control: The sway control can easily be turned completely off in dangerous or icy road conditions
After hitching a trailer, you just need to attach the sway control bar next to the tow vehicle’s hitch. Tightening the bar increases tension across the connection point, reducing sway.
Using a sway control bar can become tedious for some because they need to be unhooked every time you need to reverse.
Do I need weight distribution and sway control in a hitch?
Sway control bars are often combined with weight distribution hitches, though they can be used independently. Combining them is ideal for the best results.
Weight distribution hitches often come with a sway control bar since they complement each other well. Chain-style weight distribution hitches, like the one we covered above, often come with these bars too.
As for hitches with built-in sway control, these don’t require any DIY skills or modification to work properly. We have already covered two examples of hitches with sway control that is built into the hitch itself and not added on, with the Equal-i-zer 4-Point hitch and the Andersen Hitches hitch.
They reduce sway in slightly different ways. Hitches like the Equal-i-zer hitch connect their steel arms to steel tabs, so the friction generated reduces sway.
As we said, metal rubbing against metal can get noisy, however. The model from Andersen Hitches uses springs instead, which are perfect for creating tension.
For heavier trailers, integrated sway control hitches are more effective than slapping a sway control bar onto a different hitch. You also don’t need to disconnect built-in sway control hitches when you want to reverse, which is a great advantage for many drivers out there.
When To Use A Sway Control Bar or Hitch
Unlike weight distribution hitches, all bump-pull trailers should have an anti-sway device. This important safety kit will make your drive smoother and ward off disaster, no matter how heavy your trailer is.
That’s why many people have them despite being under most weight requirements. It’s better to be safe than sorry.
Frequently Asked Questions
Having covered the basics of weight distribution and sway control hitches, you may have specific concerns that haven’t been addressed.
Here are some of the most popular questions we hear about trailer hitches:
1. What Should I Do If My Trailer Sways?
Swaying can happen no matter how much you try to stop it. It’s one of the realities of towing a trailer or any kind of heavy cargo, so you’ll need to know how to properly stop sway once it starts.
As we mentioned, the most important thing is to slow down gradually instead of coming to a sudden stop. A sudden stop risks damaging your vehicle and the trailer and causing danger to everybody in the vicinity.
If on the road, look for somewhere that you can safely slow down and pull over without causing any distractions or disturbances to other drivers. You don’t want to slow down and come to a halt in the middle of the road, where an accident is much more likely to occur.
2. How Powerful Does The Weight Distribution Hitch Need To Be?
While weight-distributing hitches move the weight around, the full weight of the trailer is still bearing down on the connection point. A weight distribution hitch doesn’t reduce the load’s weight in any way.
This means that you should only use hitches that are properly rated for the trailer and able to tackle more pounds than the trailer weighs. If you don’t, you risk costly repairs or an even costlier accident.
3. What Is TSA?
You may see something called TSA when checking out hitches and the manufacturers that offer them. This is not the airport TSA!
TSA stands for Trailer Stability Assist, which is a program that uses sensors to monitor and control trailer sway.
By coordinating with the vehicle’s computer, the sway can be controlled more effectively.
TSA systems engage automatically when swaying is detected. Then, it tactically brakes in a way that doesn’t interfere with your driving but stops the swaying.
It’s more important in smaller vehicles that may not have weight-distributing hitches or sway control bars. Even then, TSA can still be useful for heavier trailers and the vehicles towing them.
4. Can I Make Lifting Steel Arms Easier?
If your weight distribution hitch has steel arms, you may have trouble lifting them to fix and remove the trailer. This is a common problem, especially for those who are new to towing cargo or RVs. Some tough it out, which is an option.
After you’ve done it for a while and you’re stronger, lifting the steel arms of a hitch becomes easier and faster. However, this is a chore, and there are ways to make it easier on yourself.
First, it helps if your hitch has lever handles that can be used to manipulate the arms. It’s still hard to properly lift them sometimes, especially if the hitch is in an awkward position. In that case, try to move somewhere where you have full access to the hitch from most angles.
Others make the process easier by lifting the trailer with the tongue jack. This levels the truck and the trailer, so you won’t have to move the arms as much to make the connection.
As we have stated, many issues result from your towing vehicle and the trailer being uneven against each other, so using a tongue jack helps with that a lot.
5. Does A Weight Distribution Hitch Need A Sway Control Bar?
Sway control bars are installed on hitches and, as we said, many weight distribution hitches come with a sway bar pre-installed or ready to install. So, does a weight distribution need a sway control bar? The answer is no.
There are weight distribution hitches that work independently. Since weight distribution and sway control are two different things, you can have a trailer with just the hitch. Likewise, you can just use a sway control hitch with no extra weight distributing apparatus.
That said, it depends on the kind of hitch. Also, many weight-distributing hitches sell with sway control bars. This is because sway control bars make weight distribution hitches even better, so why not if you can afford it?
That’s also why most high-end weight distribution hitches have sway control built into them. They complement each other and result in a much safer ride with no sway.
If you have a weight-distribution hitch that uses chains to hold the arms (instead of tabs) then you will need to use a sway control bar if you need to reduce sway. Chains don’t have the necessary friction, so a sway control bar generates the friction instead.
6. Do Weight Distribution Hitches Work In Tight Spaces?
Weight distribution hitches are fine for backing into tight spaces – it’s the sway control bar that might be a problem. If you are backing into a tight space or through a tight turn, you’ll need to disengage it before you try reversing or pulling off any tight maneuvers.
If you try the maneuver without disengaging the sway control bar, you’ll find it very difficult to move the vehicle. They control small movements, after all, and a lot of movements you make in tight spaces/on tight corners will be small.
Then you risk overdoing it and causing damage to your vehicle by knocking it against a wall or somebody else’s car.
7. Are Weight Distribution Hitches Needed For 5th-Wheel Trailers?
The weight of a 5th-wheel trailer is focused on the center of your truck and on both of the axles, so it already has its own form of weight distribution. This makes sway much less of a problem, which makes sense when these trailers are flat and used to move cargo around.
You can’t be too safe, however, which is why some still use weight distribution hitches with 5th-wheel trailers. They are more common for short-bed trucks that can’t distribute the weight across as large an area.
Learn More: Types of Fifth Wheel Trailer Hitches
They’re also useful for making sharper turns when you have a large fifth-wheel trailer fixed to your vehicle. When reversing, the hitch can slide back and create more room between the vehicle and the trailer, making turns more sudden and giving the driver more control.
Weight Distribution and Sway Control
That should be all you need to know about weight distribution and sway control, and the differences between them both.
The main takeaway is that weight distribution and sway control are not the same. While they produce the same results—stopping your trailer from swaying—they work differently.
In some hitches, they work in tandem to get the best sway control possible. Others just have weight distribution, so to get dedicated sway control, you need to install a simple bar modification.
Knowing this is crucial when hauling heavy loads. You don’t want to set off without the extra protection that weight distribution and sway control provide.
For a more in-depth look, check out this video for towing tips:
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