2008 GMC SIERRA Owner's Manual

Item Description Total
AVehicle Capacity
Weight for
Example 3=1,000 lbs
(453 kg)
BSubtract Occupant
Weight 200 lbs
(91 kg)×5=1000 lbs
(453 kg)
CAvailable Cargo
Weight=0 lbs (0 kg)Refer to your vehicle’s tire and loading information
label for specic information about your vehicle’s
capacity weight and seating positions. The
combined weight of the driver, passengers, and
cargo should never exceed your vehicle’s capacity
weight.
Certication/Tire Label
A vehicle specic Certication/Tire label is found
on the rear edge of the driver’s door. The
label shows the size of your vehicle’s original tires
and the ination pressures needed to obtain the
gross weight capacity of your vehicle. This is called
Gross Vehicle Weight Rating (GVWR).
Example 3
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The GVWR includes the weight of the vehicle, all
occupants, fuel, and cargo.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR). To nd
out the actual loads on your front and rear
axles, you need to go to a weigh station and
weigh your vehicle. Your dealer can help you with
this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
The Certication/Tire label also contains important
information about your Front Axle Reserve
Capacity. See “What is front axle reserve capacity,
and how do I calculate it?” underAdding a
Snow Plow or Similar Equipment on page 4-43.
{CAUTION:
In the case of a sudden stop or collision,
things carried in the bed of your truck
could shift forward and come into the
passenger area, injuring you and others. If
you put things in the bed of your truck,
you should make sure they are properly
secured.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
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Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
Using heavier suspension components to get
added durability might not change your weight
ratings. Ask your dealer to help you load
your vehicle the right way.
If you put things inside your vehicle — like
suitcases, tools, packages, or anything
else — they go as fast as the vehicle goes.
If you have to stop or turn quickly, or if there
is a crash, they will keep going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down
unless you need to.
There is also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving“ underOff-Road
Driving on page 4-12.
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Two-Tiered Loading
Depending on the model of your pick-up, you can
create an upper load platform by positioning
two or four 2 inches (5 cm) by 6 inches (15 cm)
wooden planks across the width of the pickup box.
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 areboard.
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
Cargo750 lbs (340 kg)
Cross Toolbox and
Cargo400 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).
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Adding a Snow Plow or Similar
Equipment
Before installing a snow plow on your vehicle, here are
some things you will need to know:
Notice:If your vehicle does not have the snow
plow prep package, adding a plow can damage your
vehicle, and the repairs would not be covered by
warranty. Unless your vehicle was built to carry
a snow plow, do not add one to your vehicle. If your
vehicle has the snow plow prep package, called
RPO VYU, then the payload your vehicle can carry
will be reduced when a snow plow is installed. Your
vehicle can be damaged if either the front or rear
axle ratings or the Gross Vehicle Weight (GVW) are
exceeded.Some vehicles are built with a special snow plow prep
package, called RPO VYU. If your vehicle has this
option, you can add a plow to it, provided certain
weights, such as the weights on the vehicle’s axles and
the Gross Vehicle Weight (GVW), are not exceeded.
The plow your vehicle can carry depends on many
things, such as:
The options your vehicle came with, and the weight
of those options.
The weight and number of passengers you intend
to carry.
The weight of items you have added to your
vehicle, like a tool box or truck cap.
The total weight of any additional cargo you intend
to carry.
Say, for example, you have a 700 lb (318 kg) snow
plow. The total weight of all occupants and cargo inside
the cab should not exceed 300 lb (135 kg). This
means that you may only be able to carry one
passenger. But, even this may be too much if you have
got other equipment already adding to the weight of
your vehicle.
4-43

Here are some guidelines for safely carrying a snow
plow on your vehicle:
Make sure the weight on the front and rear axles
does not exceed the axle rating for each.
For the front axle, if more cargo or passengers must
be carried, appropriate counter ballast must be
installed rear of the rear axle. Counter ballast must
be properly secured so it will not move during driving.
Follow the snow plow manufacturer’s
recommendations regarding rear ballast. Rear
ballast may be required to ensure a proper front and
rear weight distribution ratio, even though the actual
weight at the front axle may be less than the front
axle rating.
The snow plow manufacturer or installer can assist
you in determining the amount of rear ballast
required, to help make sure your snowplow/vehicle
combination does not exceed the GVW rating, the
front and rear axle ratings, and the front and rear
weight distribution ratio.
The total vehicle must not exceed the GVW rating.Front axle reserve capacity is the difference between
your front Gross Axle Weight Rating (GAWR) and the
front axle weight of your vehicle with full fuel and
passengers. Basically, it is the amount of weight you can
add to your front axle before reaching your front GAWR.
The front axle reserve capacity for your vehicle can be
found in the lower right corner of the Certication/Tire
label, as shown.
United States
Canada
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In order to calculate the amount of weight any front
accessory, such as a snow plow, is adding to the front
axle, use the following formula:
(W x (A + W.B.)) /W.B.= Weight the accessory is adding
to the front axle.
Where:
W = Weight of added accessory
A = Distance that the accessory is in front of the
front axle
W.B. = Vehicle WheelbaseFor example, adding a 700 lb (318 kg) snow plow
actually adds more than 700 lbs (318 kg) to the
front axle. Using the formula, if the snow plow is
4 ft (122 cm) in front of the front axle and the wheel
base is 10 ft (305 cm), then:
W = 700 lb (318 kg)
A = 4 ft (122 cm)
W.B. = 10 ft (305 cm)
(W x (A + W.B.))/W.B. = (700 x (4 + 10))/10 =
980 lbs (445 kg)
So, if your truck’s front axle reserve capacity is more
than 980 lbs (445 kg), you could add the snow plow
without exceeding the front GAWR.
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You can add heavier equipment on the front of the
vehicle if you compensate for it by carrying fewer
passengers, less cargo, or by positioning cargo towards
the rear. This has the effect of reducing the load on
the front. However, the front GAWR, rear GAWR, and
the Gross Vehicle Weight Rating (GVWR) must never be
exceeded.
{CAUTION:
On some vehicles that have certain front
mounted equipment, such as a snow plow, it
may be possible to load the front axle to the
front gross axle weight rating (GAWR) but not
have enough weight on the rear axle to have
proper braking performance. If your brakes can
not work properly, you could have a crash.
CAUTION: (Continued)
CAUTION: (Continued)
To help your brakes work properly when a
snow plow is installed, always follow the snow
plow manufacturer or installer’s
recommendation for rear ballast to ensure a
proper front and rear weight distribution ratio,
even though the actual front weight may be
less than the front GAWR, and the total vehicle
weight is less than the gross vehicle weight
rating (GVWR). Maintaining a proper front and
rear weight distribution ratio is necessary to
provide proper braking performance.
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