Towing Terms: An Explanation Of What The Most Common Terms Mean

Tow_Terms_Lead

The automotive industry is known for its alphabet soup. It seems like as soon as something new is created, it is abbreviated. That’s all fine and dandy for industry professionals but when it comes to us “regular guys” – sometimes it’s hard to decipher what something means and when it’s important.

Turnover-ball-lifestyle-(2)

Photos courtesy of B&W Trailer, Reese, and vehicle manufacturers

For reference, we compiled a list of the most important “truck terms” to know. These will be terms that are used to compare different manufacturer vehicles against one another, to understand how capable a truck is, or what type of trailer to get and how it’s best used. So bookmark this story and refer back to it often if you come across a term that you’re not quite familiar with. (Here is an article we put together with some tips from an expert who tows for a living.)

Breakaway Cables (used with electric trailer brakes)

A breakaway cable is a wire hooked from the trailer to the vehicle.  If the trailer and vehicle begin to separate this cable will tighten and engage the trailer brakes. Hopefully as a driver, you feel the brakes being applied and stop the vehicle safely before something catastrophic happens.

Ball Height

Ball height is the recommended height of the ball after the trailer coupler is attached to the vehicle (loaded).  This height is recommended by the trailer manufacture.

Curb Weight

Curb weight is the weight of the vehicle with all of its fluids (fuel, windshield wiper fluid, etc) and factory equipment.  This does not include you or any of your stuff, just the vehicle and its components.

Converter / Adapter

Trailer electric plugs vary by manufacturer. As such, there are converters that convert almost any of the types of plug to another.

20321 (1)

Adapters are available in a number of different combinations. If you look hard enough, probably every common type of connector can be converted.

2013 Ram 3500 Heavy Duty

This Ram is hooked to a gooseneck trailer (yes, we know the trailer jack is down).

Coupler

The coupler is the part of the trailer that goes over the ball and attaches the trailer to the vehicle.

Electric Brakes

Electric brakes are on the trailer and are hooked through the electric plug.  As the driver applies the brakes, a brake module sends a signal back to activate the brakes.  Without a brake controller, electric brakes do not work.  The electric brakes can, also, be operated by the brake controller with out the driver applying the vehicle brakes.  There is usually a by-pass lever to apply the trailer brakes independently if need be.

3 Fifth WheelFifth-Wheel Hitch

The fifth-wheel hitch is a hitch that is placed in the bed of a truck.  They are placed over the rear axles and use a special king pin to attach the trailer to the truck.

Fifth-Wheel Trailer

A fifth-wheel trailer mounts to a fifth wheel hitch.  These trailers allow for tighter turning compared to bumper pulls.

Gooseneck Hitch

A gooseneck hitch is, also, mounted in the bed of a pickup. This hitch is placed 2 to 6 inches in front of the rear axles and utilize a larger ball than a bumper type mount.

5 Gooseneck

Gooseneck Trailer

A gooseneck trailer mounts on a ball in the bed of a pickup.  The trailer pivots on a coupler that’s round.  This gives the trailer a greater turning radius which is needed as trailers with a gooseneck are generally larger, than bumper pull type trailers.

Gross Combination Weight (GCW)

This is the actual weight of the vehicle and trailer combined.  The trailer and vehicle are fully loaded with any and all gear, including passengers and fuel.

Gross Combination Weight Rating (GCWR)

This is the manufacturers’ rating for a specific vehicle and its cargo with trailer.  This is a rating not an actual weight. (GCW is actual weight, slight difference but important to know.)

Gross Axle Weight (GAW)

This is the amount of weight actually being applied to the individual axle.

Gross Axle Weight Rating (GAWR)

This is the maximum weight the axle can safely handle. (This is the theoretical weight, GAW is the actual weight)

2015-FORD-SUPER-DUTY_SKV3_7153

This trailer uses a fifth-wheel hitch and is called a fifth0wheel trailer.

2016 Nissan Titan XD

Some factory vehicles like this 2016 Nissan Titan XD powered with a 5.0-Liter Cummins has a factory goosneck hitch available.

Gross Trailer Weight (GTW)

This is the actual weight of a trailer with all cargo loaded.

Gross Trailer Weight Rating (GTWR)

This is the rating given by the manufacturer of the maximum recommended weight of the trailer and cargo combined. (This lets you know how much the trailer could handle in ideal conditions loaded properly.)

Gross Vehicle Weight (GVW)

Refers to the actual weight of the vehicle with all cargo, passengers, fuel, etc. on board. (This includes all parts added to the vehicle, like bumpers, winches, tool boxes, lift kits etc).

Gross Vehicle Weight Rating (GVWR)

When a vehicle is designed, engineers will design the vehicle to handle a maximum amount of weight.  This maximum amount of weight is the GVWR.  It is set, regardless of what is added or subtracted from the vehicle. It is the theoretical celling as to how much the vehicle can handle safely (brakes, engine, driveline, etc).

2015-Chevrolet-Silverado-2500HD-032-mediumHitch Assembly

Most commonly referred to as the “hitch” it is the hitch receiver, ball adapter, and ball as one unit.

Hitch Ball

The hitch ball is the semi-round ball that the coupler on the trailer attaches to. The hitch ball or “Ball” is mounted on the ball adapter or bumper.  There are three common sizes, 1 7/8”, 2” and 2 5/16”.

Hitch Classes

There are five common hitch classes.  The higher the class; the higher the weight capacity of the hitch.  These are based on the trailer size, but must not exceed the vehicle’s towing capacity.

  • Class I is 2,000 lbs
  • Class II is 3,500lbs
  • Class III is 5,000lbs
  • Class IV is 7,500 but can handle up to 10,000 with a weight distributing hitch
  • Class V is 12,000 lbs but can handle 17,000lbs with a weight distributing hitch

Goosenecks and Fifth wheel hitches don’t have classes.  They are rated by their maximum weight and not by class.

2015 Ram 1500 Laramie Crew Cab 4x4 EcoDiesel

2015FordKingRanch_04

Hitch Receiver

Generally referred to as a receiver, this is the component that the ball adapter slides into. Usually mounted under the bumper of the vehicle and attached to the frame of the vehicle.

4 King PinKing Pin

A King Pin is the attaching piece of a fifth wheel trailer.  Where as other types of trailers mount on a ball that is a fixed to the vehicle, the King Pin is on the trailer and the fifth wheel hitch hold this piece.

King Pin Weight

This is the weight of the trailer that is exerted on the pin.  It is generally about 25% of the Gross Trailer Weight. (This number is similar to trailer tongue weight, except higher.)

Payload

Payload is the difference between what the vehicle actually weights (GVW) and what it could weight.  (In other words, GVW – GVWR = Payload). The number will change depending on the configuration of the vehicle. A 4 door has a higher GVW, which means a lower maximum Payload compared to a standard cab.

Plug

The plug is the wiring cable that is part of the trailer. There are lots of different sizes and types of plugs out there. When looking at hooking up a trailer, it is important to know what type of plug it uses beforehand. Otherwise, the vehicle’s lights may not work. Many people who tow lots of different trailers carry multiple adapters with them.

Removable Drawbar or Ball Mount Adapter Tow-and-Stow_resize

This is the metal piece that fits into a receiver mount.  The hitch ball will mount to this piece.

Safety Chains

Safety chains connect the trailer and vehicle together.  They are to prevent the trailer from breaking away from the vehicle and running off.  It is important to note, they play almost no roll if nothing bad happens.  These are a very important safety precaution.

Surge Brakes

Commonly referred to as hydraulic brakes, the trailers have a plunger/lever inside of the coupler. As the trailer slides forward on the ball, the brakes are applied. This happens when the vehicle slows down or backs up. The weight of the trailer pushing against the back of the coupler and activates the brakes. The harder the trailer pushes the more the brakes are applied. One common problem with surge brakes it they often apply themselves while going in reverse.  The vehicle usually can overcome the trailer brakes, but sometimes it is a pain.

Towing Capacity

Towing capacity is the amount of weight the vehicle can tow safely.  (This is calculated by the GCWR – GVW = Towing Capacity.)

Tow Rating

The manufactures recommended maximum weight of a trailer to be towed by the vehicle.

Trailer Tongue Weight

Commonly referred to as tongue weight, it is the amount of weight from the trailer that is being applied to the truck. Generally, the tongue weight is about 10% of the gross trailer weight (GTW).

66072Weight-Carrying Hitch

This is one of the most common types of hitches.  A weight caring hitch carries the load of the tongue weight and does not disburse the weight elsewhere as the weight distributing hitch does.

Weight-Distributing Hitch

The weight distribution hitch supports some of the tongue weight and with the help from spring bars (part of the hitch) distribute a percentage of the weight to the front of the vehicle.  This greatly improves steering and braking since the vehicle is caring the tongue weight from the trailer more evenly across both axles.  These are common on heavy trailers pulled by a bumper or a receiver hitch assembly.  Gooseneck and Fifth wheel hitches do not use a weight distributing device.

Article Sources

About the author

Chad Westfall

With diesel running through his veins from childhood, Chad has more than a decade of experience in the automotive industry. From editorial work to wrenching, there isn’t much he hasn't conquered head-on. When he’s not writing and shooting trucks and tech, you’ll find him in the shop working on turning the ideas floating around in his head into reality.
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