GMC 2010 Sierra Owner's Manual page 442

Vehicle Series Hitch Type
Fifth Wheel
1500
Gooseneck
Fifth Wheel
2500HD
Gooseneck
3500 Single Fifth Wheel
Rear Wheels Gooseneck
3500 Dual Rear Fifth Wheel
Wheels Gooseneck
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.
5-66
Total Weight on the Vehicle's Tires
Maximum
Tongue Weight
Be sure the vehicle's tires are inflated to the inflation
pressures found on the Certification label on the drivers
680 kg (1,500 lbs)
door or see Loading the Vehicle on page 5 33 for more
information. Make sure not to exceed the GVWR limit
1 134 kg
for the vehicle, or the RGAWR, with the tow vehicle and
(2,500 lbs)
trailer fully loaded for the trip including the weight of the
1 360 kg
trailer tongue. If using a weight distributing hitch, make
(3,000 lbs)
sure not to exceed the RGAWR before applying the
1 587 kg
weight distribution spring bars.
(3,500 lbs)
Weight of the Trailering Combination
It is important that the combination of the tow
vehicle and trailer does not exceed any of its weight
ratings
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.
GCWR, GVWR, RGAWR, Trailer Weight