2008 Infiniti QX56 Owner's Manual - Page 408

WARNING Trailer hitch components have specific weight ratings. Your vehicle may be capable of towing a trailer heavier than the weight rating of the hitch components. Never exceed the weight rating of the hitch components. Doing so can cause serious personal injury or property damage. Ball mount The hitch ball is attached to the ball mount and the ball mount is inserted into the hitch receiver. Choose a proper class ball mount based on the trailer weight. Additionally, the ball mount should be chosen to keep the trailer tongue level with the ground. lbs. gross weight, 1,000 lbs. tongue weight. This means that without using a weight distributing ballmount, the receiver is only designed to carry 5,000 lbs. When hooking up a trailer using a weight distributing hitch, always refer to the hitch manufacturer's instructions. 1. Park unloaded vehicle on a level surface. With the ignition on and the doors closed, allow the vehicle to stand for several minutes so that it can level. 2. Measure the height of a reference point on the front and rear bumpers at the center of the vehicle. 3. Attach the trailer to the vehicle and adjust the hitch equalizers so that the front bumper height is within 0 - .5 inches (0 - 13 mm) of the reference height measured in step 2. The rear bumper should be no higher than the reference height measured in step 2. Weight carrying hitches A weight carrying or "dead weight" ball mount is one that is designed to carry the whole amount of tongue weight and gross weight directly on the ball mount and on the receiver. Hitch ball Choose a hitch ball of the proper size and weight rating for your trailer: ● The required hitch ball size is stamped on most trailer couplers. Most hitch balls also have the size printed on the top of the ball. ● Choose the proper class hitch ball based on the trailer weight. ● The diameter of the threaded shank of the hitch ball must be matched to the ball mount hole diameter. The hitch ball shank should be no more than 1/16" smaller than the hole in the ball mount. ● The threaded shank of the hitch ball must be long enough to be properly secured to the ball mount. There should be at least 2 threads showing beyond the lock washer and nut. Weight distribution hitch This type of hitch is also called a "load-leveling" or "equalizing" hitch. A set of bars attach to the ball mount and to the trailer to distribute the tongue weight (hitch weight) of your trailer. Many vehicles can't carry the full tongue weight of a given trailer, and need some of the tongue weight transferred through the frame and pushing down on the front wheels. This gives stability to the tow vehicle. Another reason to have a weight distributing ball mount is to comply with the rating on your receiver. Most receivers have a weight carrying rating of 5,000 lbs. gross weight, 500 lbs. tongue weight and a weight distribution rating of 10,000 9-20 Technical and consumer information