2011 NISSAN Towing Guide    22  
 
 
TOWING  
GLOSSARY 
 
5TH WHEEL 
HITCH Located just forward of the rear axle centerline, this hitch uses a king pin to 
serve as the pivot point for the trailer. 
 
BALL MOUNT A bar that holds the hitch ball and is inserted into the hitch receiver. Also 
commonly called a drawbar. 
 
BREAKAWAY SWITCH A safety device using a trailer battery that automatically applies the trailer’s 
brakes if it should accidentally become separated from the tow vehicle. 
A breakaway switch may be used with both electric or surge trailer brake 
systems. 
 
BUMPER HITCH A reinforced bumper designed to accommodate a hitch ball. 
 
ELECTRIC TRAILER 
BRAKES When the brakes on a tow vehicle are applied, an electric current is sent to 
an actuator which applies the trailer’s brakes. 
ELECTRIC TRAILER  
BRAKE CONTROLLER A device that controls the electric trailer brakes. 
 
GOOSENECK HITCH Located just forward of the rear axle centerline, this hitch uses a ball to serve 
as the pivot point for the trailer. 
GROSS AXLE  
WEIGHT RATING (GAWR) The maximum amount of weight each vehicle axle (front and rear) is 
designed to safely carry.     
GROSS COMBINED  
WEIGHT RATING (GCWR) The maximum allowable combined weight of the vehicle and trailer, 
including passengers and all cargo. 
GROSS VEHICLE 
WEIGHT RATING (GVWR) The maximum allowable weight of the vehicle, including passengers, cargo, 
fuel, hitch, trailer tongue load, and any optional equipment. 
KING PIN 
LOAD The amount of trailer (5th wheel or gooseneck) weight pressing down on the 
tow vehicle hitch.  
         
        
         2011 NISSAN Towing Guide    23
 
HITCH BALL 
 A ball that connects the trailer to the tow vehicle hitch and provides the 
means by which the trailer pivots during cornering.  Available in a number 
of sizes and weight capacities, it must correspond to the trailer coupler 
size, and have a sufficient capacity rating for the trailer being pulled. 
 
RECEIVER HITCH A frame- or structure-mounted hitch with a receiver that allows removal of 
the ball mount. 
 
SAFETY CHAINS/CABLES Provides an emergency connection between the tow vehicle and the trailer, 
should the trailer become disengaged for any reason. 
 
SURGE BRAKES 
 Hydraulic-type braking system activated by inertia. As the tow vehicle 
begins to brake, the trailer pushes against the hitch ball, consequently 
activating the trailer brakes.   
 
TRAILER TONGUE/COUPLER The part of the trailer that extends forward to meet the tow vehicle, and also 
carries the coupler assembly. 
 
TRAILER TONGUE 
LOAD The amount of trailer (conventional) weight pressing down on the tow 
vehicle hitch. 
 
WEIGHT-DISTRIBUTING  
HITCH SYSTEM Type of hitch system that helps shift the trailer tongue weight to all trailer 
tires and the tow vehicle front tires. Strongly recommended when towing 
trailers with a Maximum Trailer Weight greater than 5,000 lbs. 
 
WIRING HARNESS 
 Provides an electrical connection linking the tow vehicle’s electrical system 
to the trailer’s system.