A trailer hitch is still the number one bolt-on accessory today for many cars, trucks and SUVs. People use a trailer hit to tow trailers, campers, boats, race cars, classic cars, hot rods, motorcycles, snowmobiles, bikes, lawn and garden tractors or anything else you can pull behind your vehicle.
Thanks to innovative designs that are engineered to fit specific vehicle applications, most hitches can be easily installed with no drilling, welding or other modifications. Wiring kits also help simplify connecting trailer lights and electric braking systems to the vehicle's electrical system. On many applications, a hitch can be installed in 30 minutes or less, including the wiring connections.
Hitches are available from a variety of aftermarket suppliers for a wide range of domestic and import vehicles. Selecting the right hitch for a particular application is the key here, which requires an understanding of the various hitch class ratings and what the vehicle will tow.
There are basically two types of hitches: weight-carrying ("deadweight") and weight-distributing ("equalizing"). Weight-carrying hitches are generally, but not always, for smaller, lighter loads. Weight-distributing hitches are generally recommended for larger, heavier trailers (anything over 5,000 lbs.).
A weight-distributing hitch has an attachment that slides into the receiver to redistribute the weight on the tongue. The hitch typically has two spring bars, one for each side of the trailer, to lift up and apply leverage to the tow vehicle. This redistributes tongue weight from the rear axle to the front and improves vehicle stability while towing.
Class I trailer hitch can handle a Gross Trailer Weight (GTW) of up to 2,000 lbs., and a maximum tongue weight of 200 lbs. The hitch may be a simple drawbar- or step bumper-type of hitch. Other hitches may have a crossbar with a small one-inch or 1-1/2-inch square receiver, or a small 2-inch by 5/8-inch receiver. This type of hitch is often used on smaller cars, mini-pickups and minivans for bike racks and light-duty towing.
Class II trailer hitch is for loads of up to 3,500 lbs. GTW and 300 lbs. tongue weight, such as a small boat trailer, snowmobile trailer, motorcycle trailer or camper. Typical installation applications include large rear-wheel drive cars, full-size vans, pickups and SUVs.
Class III trailer hitch can handle up to 5,000 lbs. GTW and 500 lbs. tongue weight. This type of hitch generally has a 2-inch rectangular receiver and is considered the "standard" type of hitch for general towing.
Class IV trailer hitch is for up to 10,000 lbs. GTW and 1,000 to 1,200 lbs. of tongue weight, and is usually a weight-distributing trailer hitch.
Class V trailer hitch is for extra heavy loads greater than 10,000 lbs. GTW and more than 1,200 lbs. tongue weight. This type of trailer hitch may have a 2-1/2 inch or 3-inch receiver with a 3/4-inch pinhole. Typical uses might be to tow a car trailer, horse trailer or unusually large boat or camper.
For really heavy towing, a Fifth Wheel trailer hitch or a Gooseneck trailer hitch that mounts in the bed of pickup truck may be required. A bed-mounted fifth wheel hitch is recommended for loads heavier than 10,000 lbs. GTW. Some of these hitches can handle loads up to 25,000 lbs.! For heavy loads, installing an exhaust "Jake Brake" is also recommended to assist in braking. A Jake Brake uses engine compression to help slow your vehicle while saving wear and tear on your brakes.
The important point here is selecting a trailer hitch that is strong enough to handle the maximum anticipated total weight of your trailer, but does not exceed the towing capacity of your vehicle. Refer to your vehicle owner's manual for maximum towing and tongue weight limitations. Also, the trailer tongue load should be kept between 10 and 15 percent of the loaded trailer weight for weight-carrying (deadweight) hitches and weight-distributing (equalizing) hitches. For larger Class V fifth wheel bed-mounted trailer hitches, up to 25 percent of the weight can be placed on the hitch.
When choosing a hitch, consider not only your current towing needs, but also any future needs that may arise. If you are towing a rowboat today, you might trade up to a bass boat next year or a small yacht a few years down the road. If in doubt, it is always best to upgrade to a higher class trailer hitch. For most full-size trucks and SUVs, this would mean installing a Class III or IV trailer hitch rather than a Class I or II trailer hitch.
WARNING: NEVER exceed the rated towing capacity of the hitch or trailer. Overloading a hitch or trailer may cause something to break or the trailer to come loose. Also, do NOT exceed the rating towing capacity of your vehicle regardless of what your trailer or hitch are rated. Trying to pull a load that is too heavy can damage your transmission or drivetrain, or cause your engine to overheat.
Once you have selected a class of trailer hitch that best suits your towing needs, you also need to consider other suspension or vehicle modifications that might be beneficial. These modifications may include stiffer springs, air springs, overload or air assist shocks, larger sway bars or even an aftermarket ATF cooler to protect the automatic transmission from overheating. Such modifications may be needed on vehicles that will be used for heavy towing and will be equipped with a Class III, IV or V trailer hitch. Another add-on that improves rear visibility when pulling a large trailer is extended side-mount mirrors. A backup camera that helps you see the trailer hitch can also make hooking up your trailer a one person job.
When installing a trailer hitch on your vehicle, make sure the hitch clears all suspension components, the spare tire (if hung underneath) and the tailpipe, and is securely mounted. Follow the hitch supplier's installation instructions and use the fasteners that are provided.
Another option is to have your trailer hitch professionally installed. Many rental stores that rent trailer also sell and install trailer hitches. Some can also do custom hitches is no simple bolt-on hitch is available for your vehicle. They will also install the wiring for the trailer light connector.
A final step is to figure out the proper ball height for the trailer. Level the trailer, then measure from the ground to the inside top of the ball coupling on the trailer. Then measure the distance from the ground to the hitch or receiver, and the height of the ball. Use these measurements to determine how much drop or rise is needed in the ballmount or receiver so the trailer will be level.
Wiring can be tricky if your vehicle does not come factory-equipped with an electrical connector for a trailer. There are basically two types of electrical trailer connectors: 4-pin (for taillights, brake lights and turn signals), and 7-pin for lights and electronic trailer brakes.
If your trailer is equipped with electronic brakes, you will need a 7-pin electrical connector. If it has no brakes or hydraulic surge brakes, you only need a 4-pin connector.
On older vehicles, installing a trailer electrical connector typically involves splicing the connector into the taillight wiring harness. You locate the correct wires for the taillights, brake lights and turn signals, then make the connection using crimp-on connectors. With newer vehicles, it's more complicated because the rear lights are often controlled by a rear lighting module. This requires a more costly electrical connector that includes a small module and plug-in style wiring harness. If you are not comfortable doing this type of installation, find a local trailer dealer to do the wiring modifications for you.
Once the electrical connector has been installed, hook up the trailer and make sure the brake lights and taillights are working properly BEFORE you hit the road. Also, test the brakes to make sure the trailer brakes are responding correctly if the trailer has electric brakes. A short test drive is also a good idea to get familiar with how your vehicle steers, handles and brakes with a trailer behind it.