Pickup Trucks 101: What You Need to Know Before Hitching Up a Trailer

Pickup trucks are simple, right? Not always. If you want to make casual motorists sweat, ask them to hook up a trailer. Hitching up a trailer can be intimidating but we're here to give you an introduction to a few basic things you might not know.

Frequently Used Towing Terms and Abbreviations

First, you’ll want to familiarize yourself with some common terms related to your truck’s weight ratings. (Please see our earlier story on this topic).

Gross combination weight rating, or GCWR, refers to your vehicle’s maximum loaded weight (gross vehicle weight rating, or GVWR), plus the trailer’s maximum loaded weight (gross trailer weight, or GTW).

Gross trailer weight is a loaded trailer's maximum weight. It's primarily dependent on a trailer's gross axle weight ratings but the trailer's tongue weight should be considered too.

Tongue weight, also known as tonnage weight or hitch weight, refers to the amount of weight pressing down on your truck’s hitch. It shouldn't exceed 10 to 15 percent of the trailer’s weight for a conventional hitch or 20 to 25 percent for a fifth wheel or gooseneck trailer. See, your truck doesn't just pull a trailer, it bears a portion of the trailer's weight too.

When loading a trailer, be sure to keep about 60 to 70 percent of the load in front of the trailer’s centerline instead of trying to spread it out 50/50 over the full length of the trailer. Remember, let the truck help with the load.

Hitch Types

Weight-Carrying Hitches:
Weight-carrying or conventional hitches are common with light-duty pickups and are frequently used for smaller trucks with a tow rating up to 5,000 pounds. The ball on a truck’s bumper or a square receiver underneath the bumper usually indicates a weight-carrying hitch. All the trailer’s tongue weight is put on the ball. That weight directly affects truck handling and braking, and that’s one of the reasons why they’re limited to lesser loads.

Weight-Distributing Hitches:
The weight-distributing hitch is an interpretation of the standard ball and receiver hitch, with additional parts that reach back from the ball point on your truck to the frame of the trailer.

A weight-distributing hitch’s equalizer bars connect truck and trailer redundantly and redistribute the leverage placed by tongue weight on the ball to more of the trailer and more of the truck frame. Also adjustable, a weight-distributing hitch is installed and then set for each trailer and truck.

Weight-distributing hitch and mechanical sway control

Weight-distributing hitches can be modified with mechanical friction sway control, a useful feature when dealing with heavier trailers. The regulating devices found on a weight-distributing hitch can also be purchased separately and installed on weight-carrying hitches for improved towing.

Weight distributing sway control is different from electronic sway control, which has been introduced recently in Ford and Ram pickups. Electronic sway control uses a truck's ABS system and a trailer's electric brakes to counteract dangerous sway conditions.

Fifth-Wheel and Gooseneck Hitches:
The heavy-duty alternative to a weight-carrying or weight-distributing hitch is the fifth-wheel hitch, which relocates the point of contact for truck-to-trailer to a more centralized spot in the truck's cargo box instead of at the bumper, most often over or before the rear axle.

Fifth-Wheel hitch

The fifth-wheel receiver looks like a giant horseshoe. It’s the same style of device you would find on the back of a semi tractor. A gooseneck hitch looks like a ball mounted on a plate in the bed.

The inherent weight-distributing setup of a fifth-wheel or gooseneckhitch helps improve towing stability compared with conventional hitches.

With a fifth-wheel, a larger portion of the mass of a heavier trailer is placed onto the truck’s suspension itself, again via the trailer’s tongue or king pin. If you’ve ever ridden in a Heavy Duty pickup and commented the ride was stiff, such as with a 2500 or 3500 Dodge or GM product or a Ford F-250 or F-350, now you understand why. These trucks are designed to handle a heavy trailer, with the load either handled by a weight-distributing hitch or a fifth-wheel attached directly to the frame.

Gooseneck hitch cutaway

An Important Note About Trailer Hitch Balls

You should also be aware that most trailer hitch balls come in three different sizes, depending on the size of your trailer's hitch and the load you're pulling. The sizes are 1 7/8-inches, 2-inches and 2 5/16-inches.

Hitch Classes

Hitch classes run from Class I to V and not exactly congruent with the aforementioned hitch designs. Each class has a maximum for tow weight and tongue weight and is subdivided again for the type of hitch, carrying or distributing, because a weight-distributing hitch can handle more weight.

Speaking of calculating actual truck and trailer weight, truck and trailer-size scales are easy to find in the Yellow Pages or online, if you don’t know exactly how much you’re hauling.

Conventional hitches are split into the following classes:

Class I:
Towing capacity of up to 2,000 pounds gross trailer weight and 200 pounds tongue weight.

Class II:
Towing capacity of up to 3,500 pounds gross trailer weight and 300-350 pounds tongue weight.

Class III:
Towing capacity of up to 5,000 pounds gross trailer weight and 500 pounds tongue weight. Also sometimes used to refer to a hitch with any two-inch receiver, regardless of rating.

Class IV:
Towing capacity of up to 10,000 pounds gross trailer weight and 1,000 to 1,200 pounds tongue weight. Although many times any hitch with a capacity greater than 5,000 pounds gross weight is referred to as a Class 4.

Trailer Connectors

7-pin trailer connector socket on a 2010 Ford F-150 SVT Raptor. A 4-pin socket is covered on the right. As you can see, the sockets can become clogged with dirt and debris over time and may need to be cleaned to work with the trailer.

Last, but not least, after hitching up your truck and trailer, you'll have to connect the electrical systems of both together using either a 4-pin or 7-pin connector.

A 4-pin connector provides power from the truck to the trailer for left and right turn signals and taillights. It's also an electrical ground point.

A 7-pin connector provides all of the functionality of the 4-pin, plus it adds a connector for a trailer brake controller and break-away switch for a trailer's electric brakes if it accidentally separates from the truck, it provides power to charge a battery for the breakaway switch and it provides reverse lights.

Final Word

This article is a quick introduction to trailer hitches. Help from a local trailer retail or repair facility is indispensable and expert advice is always worth getting.

The numbers in this story should be taken as guidelines — There is some overlap in hitch classes, and different states will rate and govern hitches differently. Some states permit certain trailer and hitch combinations without special license, while other states require certification for the exact same kit. That overlap also provides that Class IV and V might be lumped together in Class IV, while Class V could refer to fifth-wheel applications. Ask an expert if you're stuck!

It’s crucial to match your hitch with the weight capacity of your truck and weight of your trailer. A hitch that’s rated for more weight than your pickup will not increase the pickup’s capacities, and a stronger hitch will not fix an overloaded or poorly loaded trailer. Your hitch must be able to handle a trailer’s capacities while not exceeding a truck’s capabilities. Tow with the right hitch.