GMC 2010 Yukon/Yukon XL Owner's Manual page 416

Do not exceed the maximum allowable tongue weight
for the vehicle. Choose the shortest hitch extension that
will position the hitch ball closest to the vehicle. This will
help reduce the effect of trailer tongue weight on the
rear axle.
Trailering may be limited by the vehicle's ability to carry
tongue weight. Tongue or kingpin weight cannot cause
the vehicle to exceed the GVWR (Gross Vehicle Weight
Rating) or the RGAWR (Rear Gross Axle Weight
Rating). See Total Weight on the Vehicle's Tires
later in this section for more information.
After loading the trailer, weigh the trailer and then the
tongue, separately, to see if the weights are proper.
If they are not, adjustments might be made by moving
some items around in the trailer.
Be sure the vehicle's tires are inflated to the inflation
pressures found on the Certification label on the drivers
door or see Loading the Vehicle on page 5 31 for more
information. Make sure not to exceed the GVWR limit
for the vehicle, or the RGAWR, with the tow vehicle and
trailer fully loaded for the trip including the weight of the
trailer tongue. If using a weight distributing hitch, make
sure not to exceed the RGAWR before applying the
weight distribution spring bars.
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It is important that the combination of the tow
vehicle and trailer does not exceed any of its weight
ratings GCWR, GVWR, RGAWR, Trailer Weight
Rating or Tongue Weight. The only way to be sure it is
not exceeding any of these ratings is to weigh the tow
vehicle and trailer combination, fully loaded for the trip,
getting individual weights for each of these items.
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. 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.