How Ball Mounts Work

A truck towing motorbikes
Ryan McVay/Getty Images
Even when you're towing a relatively light load such as this, the right ball mount is critical for safety.

Have you ever witnessed a truck towing a boat or camper trailer down the road and it looked like the front of the trailer was sticking way up in the air? Chances are that person didn't read this article. If you plan to tow, you'll need to select the best components to make up your entire towing system. Hitches, receivers, ball mounts and hitch couplers are the main components that make up a complete towing system. Some hitches are used for heavy-duty and commercial use. Some even resemble those seen on tractor trailers. We'll learn about those in a separate article. For this article, we're going to focus specifically on ball mounts.

Up Next

A basic towing system is comprised of a tow vehicle and a trailer. The two are joined together to form a single unit that must move through turns and be both strong and well-balanced enough to be safe. You'll need a hitch on the tow vehicle, whether it is a light passenger truck or an SUV. Some hitches are fixed and don't really give you any options for removal or stowing. In most cases, hitches have a separate receiver and ball mount that can be removed and stored inside the vehicle. These types of hitches are often mounted in inconspicuous areas on the rear of the vehicle and can be hard to detect when the mount is removed. The advantage to incorporating one of these types of hitches is that you don't have to worry about your ball mount ending up on somebody else's pickup truck, and you can also change your mounts to accept various sizes of trailer couplers.

Choosing the proper ball mount just like choosing almost any other towing accessory. Safety is the most important thing to keep in mind. Most people would know that an uneven trailer (like the one you saw sticking up in the front) isn't safe. This article will give you a good grasp of the different types of ball mounts available and the advantages each brings. What's more, we'll look at just how easy ball mounts are to install and some of the accessories you can buy that will ensure your ball mount won't end up on somebody else's truck. Let's start with a quick look at your ball mount options on the next page.


Choosing Ball Mounts

A trailer hitch
Dan Driedger/iStockphoto
It's important to select the appropriate ball mount for your specific towing needs.

Several important factors come into play when determining which ball mount is right for you. These include vehicle type, towing capacity, and of course, trailer and load size. Trailer hitches, ball mounts and couplers are classified by the amount of weight they can withstand safely.

The two measurements towing accessories are typically measured by are gross towing weight (GTW) or overall weight of the trailer and load, and tongue weight (TW) which is the weight of the trailer tongue at the point where the ball mount and trailer hitch meet. In some cases, when weight distributing spring bars and other towing accessories are installed on the towing vehicle, the GTW and TW can be increased. Before we learn about your ball mount options, let's take a brief look at class ratings and the weight range each covers.

Hitch Class Max TW (WC) Max GTW (WC) Max TW (WD) Max GTW (WD)
I up to 200 lbs. up to 2,000 lbs. N/A N/A
II up to 300 lbs. up to 3,500 lbs. N/A N/A
III up to 600 lbs. up to 6,000 lbs. up to 1,000 lbs. up to 10,000 lbs.
IV up to 1,000 lbs. up to 10,000 lbs. up to 1,400 lbs. up to 14,000 lbs.
V up to 1,200 lbs. up to 12,000 lbs. up to 1,700 lbs. up to 17,000 lbs.


Now that you understand this classification system, you'll want to keep it in mind when you choose a ball mount because you'll see that information again. Ball mounts came in three common styles; straight cut, angle cut and drop cut. All three types are listed by their GTW and TW. When choosing the appropriate ball mount, you first must consider the trailer's maximum GTW and TW and compare that to the towing capacity of your vehicle. For example, if your vehicle has a 6,000-pound towing capacity, it makes no sense to choose a ball mount with a class IV or V rating. Let's take a look at the most common ball mounts you'll see for use on light passenger or heavy duty pickup trucks:

  • ­Self aligning -- ball mount with integrated aligning system similar to forming a "V" to guide the trailer coupler on to the ball
  • Multi-ball -- mount that has a ball on three or four sides that can be rotated to accept different sized couplers
  • Cushioned ball mounts -- mounts that act as a shock absorber so that the trailer weight doesn't damage the drivetrain during acceleration and braking
  • Integral ball -- a one-piece mount that does not have an opening to accept different balls; the ball is part of the mount
  • Dual-ball mount -- similar to multi-ball mounts, yet only has two balls
  • Triple-ball with pintle hook -- similar to multi-ball mounts only these integrate a pintle hook as well for use with lunette ring trailer couplers

Okay, so you've determined the weight of your trailer and the load you plan to tow. Now it's time to check the height of your hitch. Remember the trailer we talked about earlier that sloped at that funny angle? You don't want to make that mistake when you choose your ball mount. The height of your trailer could be the difference between safe towing and an accident. In order to avoid an uneven trailer load, we have to measure the trailer and hitch to make sure the vehicle and trailer are level. Remember, we want the trailer and vehicle to work as one.

First, with the towing vehicle on level ground, measure the height of your hitch receiver from the ground to the top of the ball mount opening. Next, measure the height of the hitch coupler on the trailer. Make sure the trailer is level. If the difference is greater than zero, you need a drop mount. If the difference is less than zero, you need a rise mount. In either case, mounts are available with the right amount of rise or drop to compensate for the trailer or vehicle.

Let's take a look at what you might expect to pay for a ball mount, and also determine how to install various mounts, in next section. You might be surprised at how easy it can be.


Installing Ball Mounts

If you haven't already checked, make sure you are set to purchase a ball mount that will slide into the hitch receiver on you vehicle. The size is labeled on most receivers. If you can't find the size anywhere, measure the square opening. In general, most receivers are 2" square hollow shank and accept 2" ball mounts. Once you have all of your rise or drop measurements calculated and your class ratings determined, it's time to purchase your ball mount. Here's what specifications on a typical straight ball mount would look like:

  • 2" Receiver
  • Rated at 5,000 lbs. GTW / 500 lbs. TW
  • Requires a 1" shank ball
  • Hollow Shank
SUV and trailer
Jill Fromer/iStockphoto
Heavier loads, like the one shown here, require a larger tow vehicle and stronger hardware.

You can expect to pay anywhere from $20 to $100 or more for a solid ball mount. Those cushioned ball mounts you learned about in the previous section are pricier because they have some internal components that cost more to manufacture and added technology that bumps up the price.

Ball mounts are secured using a pin and a clip. These pins -- blunt on one end -- slide through holes in the receiver and ball mount and are fastened with the pin on the opposite side of the butted end. Because these pins are easy to remove, the ball mounts can be quickly removed for storage. If you don't feel like removing the ball mount, hitch locks are available on the market, too. Any retail location that sells towing accessories will certainly be able to point you in the right direction to find a hitch lock.

Once you have your ball mount, it's time for the very simple installation procedure. Begin by removing the pin and setting it to the side. Next, slide your ball mount into the receiver making sure the top side of the shank is facing up. Once it's in, line up the holes and insert the pin and clip. Check the clip to make sure it is properly fastened and give the ball mount a good tug. Now you're ready to install your ball (if you haven't already) and you're ready to tow. That's all there is to it.

Whether you decide to go with the old school fixed trailer hitch or a more versatile hide-away hitch with a removable ball mount, keep in mind the information concerning gross towing weight and tongue weight. More often than not, a trailer that has too much forward weight will become unstable under breaking and it may even cause you to lose control of your vehicle. At the same time, a trailer with too much of its weight toward the rear will pull the rear of your vehicle up and take weight of your rear wheels. That's no good either, as you could lose traction or possibly even your trailer. Also, make sure you have a level trailer and hitch system. Believe it or not, a tape measure and a little attention to detail can be all you need to make a well informed buying decision when it comes to your towing accessories.

If you'd like to learn more about towing and towing related topics, cruise on over to the next page.

Related HowStuffWorks Articles

More Great Links


  • "Choosing the Correct Ball Mount." (Oct. 4, 2008)
  • "Cushioned Ball Mounts." (Oct. 3, 2008)
  • The Hitch Corner. (Oct. 4, 2008)
  • USA Trailer Hitches. "Hitch Classes." (Oct. 2, 2008)