Introduction to How Hitch Couplers Work
Luis Castaneda Inc./Getty Images
It's no hot rod Camaro, but it still would be a shame to loose control of this camper.
Imagine you and your family are off to one of the coolest weekend car shows and drag racing events around, and you're towing your hot rod Camaro on your brand new trailer. You're taking it nice and slow through the curvy mountain roads when suddenly a deer jumps out and makes a break for the other side of the road. Immediately you react, and as instinct takes over, you jerk the steering wheel hard to one side and slam on the brakes. The next thing you know, you begin to lose control of the rear end and the trailer comes around toward the front of the truck. Just as you think all is lost and you are destined to slide off the side of the road, the trailer snaps free and your truck immediately regains rear traction. That's good for you, but not so good for your trailer -- or for oncoming traffic.
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After the dust settles and you've had a moment to catch your breath, you inspect the damage. The trailer is damaged pretty heavily, but luckily the slope of the mountain kept it from careening into the oncoming lane. As you scratch your head and try to get your mind around what just happened, you notice the trailer hitch seems to still be attached to your truck. As odd as it seems, the hitch appears to have broken away from your trailer. You think back to when you bought the trailer and hitch, and nothing makes sense. A closer look at the hitch reveals the hitch coupler, the part of the trailer that slips over the trailer ball mount, in two pieces. As it turns out, you didn't choose and install the proper hitch coupler when you bought the trailer. Thankfully, nobody was hurt and the Camaro made it through the ordeal. It could have been a lot worse. As you find out later, the hitch coupler you installed did not match the weight of your load. That's why it failed.
Of course, you could have avoided this scenario. In fact, if you choose the appropriate hitch coupler and towing accessories, you're that much closer to safe towing. This article aims to shed light on how to properly choose and install hitch couplers so you can tow safely. Let's start by looking at your choices in the next section.
Choosing Hitch Couplers
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Heavy-duty hitch hardware is required for extremely heavy trailers.
The basic duty of a trailer hitch coupler is to secure the trailer to the ball mount, which is located on the hitch receiver. All couplers have a mechanism that locks the tongue to the ball mount. Towing a trailer can be a balancing act that requires a bit of driver skill and proper planning. Anytime you choose a hitch and coupler, you must first determine several factors. First, weigh the trailer to measure the gross trailer weight (GTW) and the tongue weight (TW). These two measurements will allow you to determine the best option for safe towing. To measure TW, place a bathroom scale on top of a cinder block and drop the tongue level as if you were hitching the trailer. You may need to adjust the height of the scale to make sure you keep the trailer level. If the tongue weight of your trailer is heavier than 250 pounds, you may need to use a larger scale. When measuring GTW, you want to make sure you are weighing a fully loaded trailer. You can usually find these types of scales at truck rental yards and recycling centers.
The second factor to consider is towing capacity. This refers to the amount of total weight a vehicle can tow in conventional mode whereas weight distributing refers to a trailer equipped with spring bars that distribute the weight between the front and rear axles. Finally, make sure you understand your vehicle's maximum towing capacity.
Trailer hitches, ball mounts and couplers are classified by the amount of weight they can withstand. Before we learn about your hitch coupler 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.
Once you have determined the tongue weight and gross trailer weight and have looked up the towing capacity of your vehicle, it's time to choose a hitch coupler. Let's take a brief look at the different types and their characteristics below:
- Straight tongue/channel style -- coupler with a square tubular mounting sleeve or tongue that can be bolted or mounted to trailer
- Fold-away straight tongue -- similar to a channel style only they can be moved 180 degrees for stowing away
- A-frame -- solid stamped steel couplers that are used for heavier loads
- Flat mount couplers -- instead of a channel, the mounting face is flat and can be bolted or welded
- Lunette ring -- steel ring that is used in conjunction with a pintle eye hitch, which is used for heavy trailers
- Gooseneck -- long tubular shaft coupler that is used in conjunction with a gooseneck hitch, which is commonly used on heavy trailers such as horse trailers
Channel or A-frame couplers are the most common choice for class I, II and III trailers. Channel couplers slip over a square steel tube or tongue while an A-frame coupler mounts on an angled A-frame tongue. The A-frame couplers have a wider base, so they can bear more weight. When choosing a channel coupler, make sure to match it with the same tongue size.
Lunette ring couplers are used with pintle eye hitches and can be fixed or adjustable. A fixed Lunette ring coupler, commonly known as a four-hole base Lunette ring coupler, is attached to the trailer using four bolts. An adjustable Lunette ring coupler slides up and down inside a channel bracket and can be adjusted for different heights depending on the height of the trailer mount.
Now that you know what you're looking for, let's consider price and installation in the next section. You'll be towing in no time.
Installing Hitch Couplers
Once you've determined your vehicle's towing capacity and the maximum weight your trailer can haul, you're ready to purchase a coupler. Most channel and A-frame couplers range in price from $15 to $100, depending on the grade of steel and finish. For some of the more specialized couplers such as lunette rings and goosenecks, expect to pay upwards of $250 to $400. Couplers can be found through online retailers that sell towing accessories or catalog companies such as JC Whitney. Don't be afraid to shop around to get the best price once you've qualified your needs.
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No matter what type of load you're towing, it's important that you have the proper hitch coupler.
Now that you have selected the right coupler, it's time to consider installation. You have the choice of installing your coupler on your own or having it done professionally. In some cases, where welding is necessary, you may have no other option than to have the coupler installed professionally. But if you purchase a channel or A-frame coupler, you may be able to install it with common hand tools. Let's walk through installation of a channel or A-frame coupler.
Whatever you choose, the coupler must match the tongue on your trailer. Most of the time, the coupler has pre-drilled holes for inserting mounting bolts. Before bolting the coupler to the tongue, make sure everything fits properly. Check the space between the two components to make sure you have no excessive play. The coupler should have an internal stop that the tongue will rest against. A properly fitting coupler will butt up against the tongue and allow for maximum overlap. In essence, your installed coupler will become an extension of the tongue. For this reason you may choose to weld the two components together; however, bolting the two should provide enough strength in most cases.
You will probably have to drill holes in the tongue before you can mount the coupler. Use the pre-drilled holes in the coupler as a guide and drill appropriate sized holes for whatever bolt size you have. Once your holes are drilled, make sure the two surfaces are free of metal shavings and slide the coupler over to check the fit once again. After you have ensured the proper fit, insert the bolts and lock nuts and tighten with a torque wrench. If the coupler came with hardware and instructions, refer to the specifications for torque settings.
If you are able, you may decide to weld your coupler in place. Keep in mind, welding the coupler will make it more permanent and if you ever decide to change it out, you may have to cut it off with a torch and weld on a new tongue.
If you just don't feel up to the task or have a more unique situation and want to make sure you have your coupler installed correctly, you may want to consider having a professional handle the installation. Prices ultimately vary by market and job complexity, but most automotive shops or rental centers can do the job. Self-installation is obviously the less expensive way to go, but there is no shame in handing the welding and complex installation over to someone who does it for a living.
Be sure you select the correct coupler before any installation. Also, keep in mind the factors for selecting the right coupler so you can steer clear of the scenario we saw when towing that precious Camaro.
If you'd like to learn more about towing and towing related topics, follow the links on the next page.