Glossary of Trailer Terms

There are many words unique to the world of trailers and we do not intend to cover them all. The following is a comprehensive guide to the most commonly used ones. If you need to know the meaning of a related term not listed below, find a trusted local trailer dealer near you.


The pin, bar, shaft, or the like, on which a wheel or pair of wheels rotates.

Ball mount (also called a Drawbar)
A removable hitch ball platform that slides into the receiver of a hitch and fastens with a pin and clip. Different ball mounts can be used to raise or lower the height of the ball to allow for level trailer towing.

The neck of the trailer at a rounded or obtuse angle.

Converts 3-wire tow vehicle electrical systems to 2-wire systems by integrating the stop and turn signal circuits as is common in trailer wiring.

Cargo Trailer
An un-powered vehicle pulled by a powered vehicle; commonly used for transport of goods and materials.

This is the leading-positioned part of a trailer tongue that secures to the tow vehicle hitch ball.

Cross Members
These are the structural, load carrying components supporting the floor of the truck body or trailer. We use only materials that are high in strength, but light in weight to maximize the weight and volume of the cargo being hauled.

See Ball Mount.

G.V.W. or Gross Vehicle Weight
The total weight of a vehicle including all of its contents and passengers.

G.V.W.R. or Gross Vehicle Weight Rating
The total weight of the trailer by a manufacturer as the recommended maximum weight of a vehicle plus the weight of the load placed on the trailer (although the gross vehicle weight rating of a truck is the combined weight of the truck, trailer, and the load on the trailer).

A device that attaches directly to a separate vehicle and connects the tow vehicle and the trailer. Below are the most common types. Our Service Specialists can tell you what kind of hitch works best for your trailer.

Hitch Ball
The attachment on a vehicle where a trailer coupler is attached. It is named after its shape. 

Hitch Bar
See ball mount or drawbar.

Hitch System Rating
This is the maximum weight you can tow with your configuration. To find out how much you can tow, consider the maximum tow weight of your vehicle. Check your vehicle's manual or contact the manufacturer for this information, then select the proper equipment. Keep in mind gross trailer weight and tongue weight as the two main factors in selecting towing equipment.

It can be any part that slides into a receiver style hitch, such as a ball mount, winch, bike rack, etc. 

LED or Light Emitting Diode
A diode is an electrical component with two terminals which conduct the electricity only in one direction. With an electrical current, the diode emits a bright light around the small bulb.

Locking Pin
A key-locking hitch pin whose function is to avoid removal of an insert. 

Original Equipment Manufacturer.

Pintle Hook
The part of a pintle hitch which attaches to the tow vehicle.

Pintle Mount
An insert for a receiver hitch which has a shank unto which a pintle hook is bolted to.

It is the part used to connect trailer wiring to a tow vehicle. 

It is the part of a trailer hitch which holds inserts such as ball mounts or drawbars.

Rock Shield
Often called a “Rock Guard”, it’s a smart and inexpensive way to protect your cargo from rocks or other debris shot at it at the speed of movement.

Safety Chains
They are attached to the trailer tongue with hooks on their free ends and keep the trailer connected to the tow vehicle in the event the coupler or hitch ball detach from the tow vehicle. Safety chains must be secured every time a trailer is towed. 

Single Axle Trailer
It is a towing unit featuring a single axle, to which two wheels are connected to allow the trailer to roll forward. The single axle trailer is often rated to haul only a certain amount of weight. The size of the trailer being hauled is dictated by the hitch receiver's hauling capacity as well as the size of the vehicle. Chains are connected between the trailer and the hitch as a back-up security system.

Spring Bar
It is the part of a weight-distributing hitch system which works to distribute trailer tongue loads to the tow vehicle forward axle. 

Sway Control Device
A device similar to a shock absorber which resists swaying movement of a trailer tongue sometimes caused by passing vehicles and wind.

Surge Brake System
This system is entirely self-contained on the trailer and activates when the tow vehicle decreases speed.

Tandem Axle Trailer
Also referred to as a “Double Axle Trailer” or “Dual Axle Trailer”, it is a trailer with two axles, one behind the other (has a total of 4 wheels).

The part of the trailer which includes the coupler; it extends forward from the trailer box. 

Tongue Weight
It’s defined as the downward force exerted on the hitch ball by the trailer coupler.

Tow vehicle
It is the vehicle that pulls a trailer.

Utility Trailer
It’s an unpowered vehicle that is pulled or towed by a powered vehicle such as a car or truck via a hitch. It can be built as a flat-bed open-air trailer or as an enclosed trailer with shelving units or specialty equipment built in. It’s meant to haul some sort of equipment, either for professional or recreational use.

The part of the trailer that attaches to the vehicle hitch, takes its name after its shape, of a letter “V” with the vertex pointing forward.

Weight Distribution System
A hitch system that enhances handling and braking and increases trailer towing capacity. This system is built around a receiver hitch, which includes supplemental equipment that distributes trailer tongue loads to the trailer axle(s) and the tow vehicle front axle.