Online Hitch Reviews Trailer Hitches   Call Today     (866) 843-2010
Advanced Search  

The Learning Center

Glossary of Towing Terms

Your towing capacity is only as great as your weakest link..Let CURT provide you with: The Strongest Links.

It is very important to review an operators manual before purchasing a towing system. Your vehicle manual has helpful information about your vehicles capabilities and limitations. You also need to be aware of the different laws and restrictions which exist when you tow from state to state. Your area State Patrol is a good resource for finding this information.

TONGUE WEIGHT (TW) is the downward force that is exerted on the hitch ball by the coupler. The tongue weight will vary depending on where the load is positioned in relationship to the trailer axle(s). To measure the tongue weight, use either a commercial scale or a bathroom scale with the coupler at towing height.When using a bathroom scale with heavier tongue weights, use the method shown and multiply the scale reading by 3.

(GTW) The Gross Trailer Weight is the weight of the trailer & cargo. Measure this by putting the fully loaded trailer on a vehicle trailer.

(WC) is the total weight of both the trailer and the cargo inside. Never exceed the weight capacity of your trailer hitch.

A device used to reduce the lateral movements of the trailer that are caused by the wind. This works in conjunction with weight distribution hitch. Do not use this on a Class I or Class II hitch, or with surge brakes.

The primary device attached to the rear of the vehicle which allows you to tow. There are five classes of hitches. It is very important to choose the correct class of receiver hitch. Gross trailer weight and tongue weight will determine the hitch that is needed. Do not exceed the lowest rating of any component of your towing system.

Class 1 Receiver Hitches
GTW 1,000-2,500 WC
Class 2 Receiver Hitches
GTW up to 3,500 WC

Class 3 Receiver Hitches
GTW up to 6,000 WC / 10,000 WD

Class 4 Receiver Hitches
GTW 10,000 WC / 12,000 WD
Class 5 Receiver Hitches
GTW 12,000 WC / 14,000 WD

These hitch applications are used only for light weight towing, including bike racks and cargo carries. Towing should not exceed vehicles bumper gross towing weight. Hitch Capacities are limited to bumper capacities. DO NOT USE A WEIGHT DISTRIBUTION HITCH WITH THESE PRODUCTS.

The ball mount is placed inside the opening of the receiver hitch which is mounted to the vehicle. Make sure a hitch pin and clip is properly securing the ball mount to the receiver hitch before you began towing. Ball mounts are grouped into three styles.

The connection from the hitch to the trailer. There are many factors that determine the correct hitch ball.

  • Most important is the hitch ball’s gross trailer weight rating.
  • The mounting platform must be at lease 3/8” thick
  • The hole diameter must not be more than 1/16” larger that the threaded shank.
  • Every time you tow, check the nut and lock washer to make sure they are fastened securely

The component that is placed of the trailer ball to connect the vehicle to the trailer. Be sure that the coupler size matches the size f the hitch ball and that the coupler handle is securely fastened. To determine what size hitch ball you need for your application you will need to know the size of coupler that is on the trailer. Be sure your coupler is properly adjusted to the ball you are using. NOTE: For added security the use of safety devices such as Coupler Safety Pins and Locks is strongly recommended.

Safety chains are a requirement and should be crossed under the tongue of the trailer so that the tongue will not drop to the road of it becomes separated from the hitch. Always leave enough slack so you can turn. Never allow the safety chains to drag on the ground and never attach the chains to the bumper.

Trailer Classification: Safety Chain Breaking Force - Minimum
Class 1: 2,000 lbs. (8.9 kN)
Class 2: 3,500 lbs. (15.6 kN)
Class 3: 5,000 lbs. (22.2 kN)

The strength rating of each length of safety chain or its equivalent and its attachments shall be equal to or exceed in minimum breaking force the GVWR (Gross Vehicle Weight Rating) of the trailer.

Use this table to select the correct class of hitch for your vehicle. Refer to not only vehicle type, but also the trailer(s) that you will be towing.

Choose The Right Hitch




Add weight of recreation vehicle and cargo

Trailer lights, Electrical Brakes, Break-away systems – Every time you tow, be sure to check that all components are working properly.

Wiring Location Guide for T-Connectors and Other Wiring Kits

Glossary of Towing Terms

Trailer Hitches