Glossary of Terms

Glossary of Terms
  • GVWR: Gross Vehicle Weight Rating
  • Trailer Weight: The empty weight of the trailer fully assembled.
  • Payload Capacity: The total weight capacity of the trailer. GVWR -Trailer Weight = the total payload capacity.
  • Tongue Weight: The amount of the trailers weight that is transferred to the tow vehicle through the trailer tongue or gooseneck.
  • Bumper Pull: A trailer that attaches to a hitch and ball that is attached to the tow vehicles frame or bumper.
  • Gooseneck: A trailer that attaches to a hitch ball in the bed of a truck over the rear drive axle.
  • Cargo Trailer: Also referred to as an Enclosed Trailer, a trailer whose cargo area is protected from the elements.
  • Enclosed Trailer: Also referred to as a Cargo Trailer, a trailer whose cargo area is protected from the elements.
  • Utility Trailer: Also referred to as an Open Trailer, a trailer whose cargo area is not protected from the elements and cargo area is accessible from all sides.
  • Open Trailer: Also referred to as a Utility Trailer, a trailer whose cargo area is not protected from the elements and cargo area is accessible from all sides.
  • Floor Size: The dimensions of the floor size from front to back and inside fender to inside fender.
  • Tire Size: The outside diameter of the rims dimensions. The overall diameter of the tire can change depending on the manufacture of the tires wall height and thickness.
  • Bias Ply: A tire having a foundation of plies of rubberized cords in a crisscross pattern of lines diagonal to center line of the tread.
  • Axle: A bar connecting two opposite spindles holding hubs and wheels.
  • EZ Lube: Axles that have a grease fitting installed inside the spindle that allows an easily accessible grease point for wheel bearing lubrication.
  • Coupler: A locking mechanism used to connect the trailer tongue tube to the ball of the towing vehicle. Couplers may come in many different shapes and sizes but the most common sizes are 1-7/8″, 2″ and 2-5/16″. The coupler and hitch ball must match exactly.
  • Safety Chains: Chains connected from the trailer tongue to the towing vehicle used to guide the trailer safely in case of ball or coupler failure. Two safety chains are required and must be attached to separate chain retainers.
  • Leaf Spring: A spring consisting of several layers of flexible metallic strips joined together to act as a single unit.
  • Spring Hanger: A U-shaped piece of metal used to attach leaf springs to the frame.
  • Shackle: A flat piece of metal used to connect the leaf spring to the Spring Hanger eliminating a binding action when the spring becomes compressed. Typically used in a pair.
  • Spindle: A rod that serves as an axis point for the revolving hubs connected to the axle bar.
  • Hub: The center connecting part between the wheel and the wheel bearings acting as a focal point.
  • Wheel Bearing: A structural part that supports the connection of the spindle and the hub together reducing friction and wear.
  • Wheel Grease: thick oil used for lubricating the wheel bearings adding longevity to the wheel life.
  • Bearing Protectors: Commonly referred to as bearing buddies, the purpose is to replace the dust cap so that wheel bearings can be easily grease.
  • Dust Cap: Used to cover the hub center to prevent dust and dirt from entering the grease inside the wheel bearings.
  • Lug Nuts: A heavy, rounded nut that fits over a lug stud to attach a wheel to the hub.
  • Lug Studs: A bolt installed from the back side of the hub to secure a wheel to the hub by using lug nuts.
  • Single Rear Door: A door that is hinged from one side.
  • Double Rear Door: A door that is hinged on both sides and closes in the middle with a cam bar similar to French doors.
  • Rear Ramp Door: A door that is hinged on the bottom and lowers with spring and cable assist for easy loading and unloading of material.
  • Rear or Side Ramp Gate: A gate that is hinged on the bottom that allows for easy loading and unloading of material generally covered with an expanded metal surface.
  • Rear or Side Ramps: Generally 2 independent ramps that are stored by either slide in or fold up styles with the trailer allowing you to load or unload items with different widths.
  • DOT/NHTSA: Refers to the Department of Transportation and the National Highway Traffic Safety Administration who regulate all Federal motor vehicle laws and regulations.
  • MCO: Manufacturers Certificate of Origin supplied by the motor vehicle manufacturer used to register the trailer with the local motor vehicle department to receive a title and license plate to prove ownership.
  • VIN: Vehicle Identification Number is generated by the motor vehicle manufacturer to track the date and place of manufacture of the trailer. The VIN is located on the MCO and the VIN label attached to the trailer. The VIN label also contains other information as required by DOT/NHTSA.