Glossary of Trailer hitch terms

Alphabetically categorized for your ease!

Important Hitch Articles

Table of Contents


APV – all purpose vehicle
AWD – all wheel drive
Axle – device that attaches wheels to trailer


Ball – the trailer ball is what attaches the trailer to the hitch. Ball sizes vary as do capacities by manufacturer. Balls also come in many different finishes we carry stainless and chrome finish.
Common Ball Sizes:

  • 1 -7/8inch ball with 3/4inch or 1inch shank: 2000# capacity
  • 50mm ball with 19mm shank: (European applications only)
  • 2inch ball with 3/4 inch shank: 3500 or 5000# capacity
  • 2inch ball with 1inch shank: 5000 or 6000# capacity
  • 2inch ball with 1-1/4inch shank: 6000, 7500, or 8000# capacity
  • 2-5/16inch ball with 1inch shank: 6000# capacity
  • 2-5/16 inch ball with 1-1/4inch shank: 10,000# capacity
  • 2-5/16inch ball with 1-1/4inch shank (heat treated): 14,000; 24,000; or 30,000# capacity
  • 3inch ball with 2inch shank (goose neck only): 30,000# capacity


Ball height measurement from the ground to the top of the ball or ball coupling (trailer) when parked on a flat surface and parallel to the ground. Used to determine the amount of drop or rise needed in the ball mount to make the trailer ride parallel to the ground when being towed.

Ball mount (ball mount) the part of a trailer hitch that slides into a receiver and fastens with a pin and clip to allow the attachment of a ball for towing a trailer.
Bumper the part of the vehicle which protects the front and rear ends in the event of an accident, although some on trucks may have facilities for towing, the bumper should NEVER be used as a towing device.
Bumper types
  • Step  a bumper which is intended to be used as a step
  • Stock  the original bumper on a vehicle, (also refers to NOT a step bumper)
  • Deep Drop  a step bumper shaped like a long V to lower the step surface in the center
  • Cowboy  same as deep drop
  • Roll Pan  not really a bumper but a fascia panel used instead of a bumper. This bumper is common on lowered trucks
  • OEM (original equipment manufacturer) this is the bumper that comes on your vehicle from the factory. This term is used when only one choice is available from the factory


Chassis the frame of a vehicle. This is the main structure of a vehicle, which all other parts attach to regardless whether it is uni body or frame construction.

  • Class 1  trailer hitch with capacity of up to 2000# gross trailer weight and 200# tongue weight
  • Class 2  trailer hitch with capacity of up to 3500# gross weight and 350# tongue weight
  • Class 3  trailer hitch with capacity of up to 5000# gross and 500# tongue weight. Also sometimes refers to a hitch with a 2inch receiver regardless of rating.
  • Class 4– trailer hitch with capacity of up to 10000# gross trailer weight and 1000-14000# tongue weight. Although many times any hitch with a capacity greater than 5000# gross weight is referred to as a class 4.
  • Class 5  any trailer hitch with capacity greater than 10000# gross trailer weight and 1000-12000# tongue weight. Usually a 2.5inch receiver or in some special cases a 2inch receiver.

Clip  used to retain pin in receiver style hitch

Converter  wiring converter: 5 wire systems to 4 wire systems. Used to integrate the stop circuit with the right and left circuits, with a diode on each circuit to prevent loop back to the turn signal switch, etc.

Custom Hitch  one that is designed to fit a specific vehicle


Draw bar  see ball mount
Drop-down  a ball mount with a drop in it to lower ball-height, to make the trailer ride parallel to the ground.


Equalizer (colloquialism)  see weight distributing hitch


Fifth wheel  a type of hitch that mounts in the bed of pickup truck; designed to be like hook-ups on a big tractor/trailer rigs. It uses a plate in the bed of the truck, and a pin on the trailer.
Frame  the part of a vehicle which all other parts attach to. Frame usually refers to a non-uni body chassis.
French link  a chain link with a space, allowing chain to be attached to it. The space can be closed with an attached threaded collar, thereby making the link once again integral.
FWD (acronym)  front wheel drive


GCVW  gross combined vehicle weight: GVW plus the weight of any towed vehicles or trailers
Goose neck  a type of trailer hitch which mounts in the bed of a pickup truck. Goose necks use a ball in the bed (either 2-5/6inch or 3inches in diameter), and coupler on the trailer, not to be confused with a fifth wheel
Grey Market Car  gray market cars usually have a label inside of the driver side door jamb that states that the vehicle was imported to this country and then retrofitted with approved impact absorbing bumpers and smog equipment to comply with U.S. rules.
GVW  gross vehicle weight: the total capacity of a vehicle including all of its contents and passengers, and the weight of the vehicle itself.


Hitch Bar  see draw bar
Hitch weight  see tongue weight


Insert any item which slides into a receiver hitch (i.e. Ball mount, bike rack, winch, etc.)
ITOR (acronym)  inside top of receiver: a measurement from the ground to the upper inside edge of the receiver tube, used to help determine measurements for drop down or rise.


Jack Knife  any time the trailer tongue collides with the tow vehicle from turning too sharply. Usually occurs while backing up.


LB  long bed (i.e. long bed pickup truck or van)
Locking Pin  hitch-pin locks with a key to prevent theft of the ball mount or other insert


OEM – Original Equipment Manufacturer


Pin  used to fasten any insert into a receiver hitch. Available in standard and locking configurations.
Pintle  a type of hitch that uses a round ring called a lunette on the trailer end. Sometimes referred to as a GI or military type hitch. Pintles have closing jaws; locking the lunette in. these are also available in pintle/ball combinations.
Pintle Mount  an insert for a receiver, having a shank with a flat plate to bolt a pintle to. These are typically adjustable for vertical height.
Plug the connector used to connect trailer wiring to the tow vehicle; plug refers to the trailer end of the connection, socket refers to the car end.


Quick Link  see French link


Receiver  The parts of a trailer hitch that attaches to the frame of a tow vehicle, and has a receptacle for inserting an attachment.
RWD  rear wheel drive


SB  short bed (i.e. short bed pickup or van)
Shank  see insert
Socket  wiring connector used on the CAR end of a trailer wiring connection. The plug is the end used on the trailer
Spring Bar  the part of weight distributing hitch which does the lifting. A lever bar typically is made of spring steel
Sub-Frame  The part of the vehicle which supports the engine and front suspension on a uni body vehicle.
SUV  sport utility vehicle
Sway Bar  a specialized spring which is part of the suspension on a vehicle. Not a part of a trailer hitch. Sometimes confused with a weight distributing hitch.
Sway Control Device  a device which goes between a weight distributing ball mount and a trailer to reduce the likelihood of sway caused by passing vehicles and wind. This device should not be used to correct sway caused by improper tongue weight (too little or too much).


Tag-A-Long Trailer  a trailer that is pulled behind a vehicle with a chassis mounted t trailer hitch as opposed to a fifth-wheel or goose neck.
Tandem axle  two axles (four wheels)
Tongue  see coupler
Tongue Weight  the amount of weight the trailer puts on the tongue of a trailer or on the ball of the hitch. This load is a vertical load. It should be at least 10% of the gross trailer weight.
Tri-axle  3 axles (6 wheels)
Trunnion  the replaceable end of a square bar weight distributing hitch which attaches to the ball mount.


Uni-body  a vehicle that has frame and body integral. Usually has a sub frame for the front end which mounts the engine and suspension.
Universal hitch  (no such thing) some would have you believe that these exist. And they do, but the inherent compromises involved in making a hitch that fits everything make them fit nothing correctly.


V-5  a system of rating trailer hitches established by the Trailer Hitch Manufactures Association (THMA)
VIN  vehicle identification number


WB – wheel base
Weight carrying  a towing situation whereby all of the tongue weight is carried directly on the rear of the tow vehicle and on the hitch.
Weight distributing  a towing situation whereby some or all of the tongue weight is redistributed by use of a weight distributing attachment through the vehicles chassis from the rear axle to the front.
Weight distributing hitch  an attachment, which slides into a receiver hitch, and redistributes hitch (tongue) weight. Typically uses 2 spring bars, one on each side of the trailer to lift up and apply leverage to the tow vehicle, thereby redistributing tongue weight from the e rear axle to the front. This provides more vehicle stability while towing. Weight distributing hitches currently come in two configurations: one with square bas that hook to the center of the ball mount, called trunnion bars, and one with round bars that slide into the bottom of the ball mount, called round bars.
Weld nuts  weld nuts is a term for threaded nut inserts that are already in the chassis installed by the vehicle manufacturer.
Wiring system  3wire: tail lights, left turn and stop, right turn and stop (3 circuits): usually used where the trailer ball provides a ground. NOT A GOOD IDEA, the lights will flicker and shut down randomly. 4wire: tail lights, left turn, right turn, stop, ground (5 circuits). Most trailers are 4wire systems. When your vehicle is a 5wire and trailer a 4wire, a converter is required.