GMC 2007 Sierra - Manual (Page 415)

Two-Tiered Loading
By positioning four 2 inches (5 cm) by 6 inches
(15 cm) wooden planks across the width of
the pickup box, you can create an upper load
platform. The planks must be inserted in the pickup
box depressions. The length of the planks must
allow for at least a 3/4 inch (2 cm) bearing surface
on each end of the plank.
When using this upper load platform, be sure the
load is securely tied down to prevent it from
shifting. The load’s center of gravity should be
positioned in a zone over the rear axle. The zone
is located in the area between the front of each
wheel well and the rear of each wheel well.
The center of gravity height must not extend above
the top of the pickup box flareboard.
Any load that extends beyond the vehicle’s
taillamp area must be properly marked according
to local laws and regulations.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.
Add-On Equipment
When you carry removable items, you may need
to put a limit on how many people you carry
inside your vehicle. Be sure to weigh your vehicle
before you buy and install the new equipment.
Notice: Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.
*Equipment Maximum Weight
Ladder Rack and Cargo 750 lbs (340 kg)
Cross Toolbox and Cargo 400 lbs (181 kg)
Side Boxes and Cargo 250 lbs per side
(113 kg per side)
*The combined weight for all rail-mounted equipment
should not exceed 1,000 lbs (454 kg), excluded
1500 crew cab models with 5 ft 8 in (173 cm) box
length. A reinforcement kit for rail-mounted add-on
equipment is recommended. See your dealer.
Ladder racks are not recommended for 1500 crew
cab models with 5 ft 8 in (173 cm) pick-up box length.
Maximum recommended cross-mounted toolbox and
cargo weight is 300 lbs (136 kg) for the 1500 crew
cab with 5 ft 8 in (173 cm) pick-up box length.
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