2010 GMC Sierra 1500 Crew Cab Owner's Manual - Page 443

Hitches The correct hitch equipment helps maintain combination control. Most small-to-medium trailers can be towed with a weight carrying hitch which simply features a coupler latched to the hitch ball. Larger trailers may require a weight distributing hitch that uses spring bars to distribute the trailer tongue weight among the two vehicle and trailer axles. Fifth wheel and gooseneck hitches may also be used. See "Weight of the Trailer Tongue" earlier in this section for rating limits with various hitch types. If a step-bumper hitch will be used, the bumper could be damaged in sharp turns. Make sure there is ample room when turning to avoid contact between the trailer and the bumper. Consider using sway controls with any trailer. Ask a trailering professional about sway controls or refer to the trailer manufacturer's recommendations and instructions. Weight‐Distributing Hitch Adjustment A: Body to Ground Distance B: Front of Vehicle When using a weight-distributing hitch, the spring bars should be adjusted so the distance (A) is the same after coupling the trailer to the tow vehicle and adjusting the hitch. 5-67