2004 GMC SIERRA Rear

{CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
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.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
This will help you decide how much cargo and installed
equipment your truck can carry.
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'll 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's also important loading information for off-road
driving in this manual. See ªLoading Your Vehicle
for Off-Road Drivingª under
Off-Road Driving with Your
Four-Wheel-Drive Vehicle on page 4-20.
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Payload
Payload capacity is the maximum load capacity that your
vehicle can carry. Be sure to include the weight of the
occupants as part of your load. If you added any
accessories or equipment after your vehicle left the
factory, remember to subtract the weight of these things
from the payload. Your dealer can help you with this.
Remember not to exceed the Gross Axle Weight Rating
(GAWR) of the front or rear axle.
Two-Tiered Loading
By positioning four 2º x 6º 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 ¯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 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) excludes
1500 crew cab models with 5' 8²box 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' 8²
pick-up box length.) Maximum recommended cross
mounted toolbox and cargo weight is 300 lbs. (136 kg)
for the 1500 crew cab (with 5' 8²pick-up box length.)
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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 option called RPO VYU
(snow plow prep package), 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 GVW, are
exceeded.
Q:How do I know if my vehicle can handle a
snow plow?
A:Some vehicles are built with a special package,
called RPO VYU (snow plow prep package). 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 GVW, are not
exceeded.
Q:How heavy can a snow plow safely be?
A: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.
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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.
Q:What is front axle reserve capacity, and how do
I calculate it?
A:Front axle reserve capacity is the difference
between your front GAWR and the front axle
weight of your truck 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 Certi®cation/Tire
label, as shown.
United States
Canada
4-65

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 lb. (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 lb.
(445 kg)
So, if your truck's front axle reserve capacity is more
than 980 lb. (445 kg), you could add the snow plow
without exceeding the front GAWR.
Q:What if I want to add heavier equipment to my
vehicle?
A: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 GVWR must never be
exceeded.
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{CAUTION:
On some vehicles equipped with certain front
mounted equipment, such as a snow plow, it
may be possible to load the front axle to the
front 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. 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 GVWR. Maintaining a proper front and
rear weight distribution ratio is necessary to
provide proper braking performance.
Q:What is total vehicle reserve capacity?
A:This is the difference between your GVWR and
the weight of your truck with full fuel and
passengers. It is the amount of weight you can
add to your vehicle before reaching your GVWR.
Keep in mind that reserve capacity numbers
are intended as a guide when selecting the amount
of equipment or cargo your truck can carry. If
you are unsure of your truck's front, rear or total
weight, go to a weigh station and weigh your
vehicle. Your dealer can also help you with this.
The total vehicle reserve capacity for your vehicle
can be found in the lower right corner of the
Certi®cation/Tire label as shown previously.
See your dealer for additional advice and information
about using a snow plow on your vehicle. Also,
see
Loading Your Vehicle on page 4-57.
4-67

Truck-Camper Loading Information
This label is inside your glove box. It will tell you if
your vehicle can carry a slide-in camper, how much of a
load your vehicle can carry, and how to correctly
spread out your load. Also, it will help you match the
right slide-in camper to your vehicle.
When you carry a slide-in camper, the total cargo load
of your vehicle is the weight of the camper, plus the
following:
·Everything else added to the camper after it left the
factory
·Everything in the camper
·All the people inside
The Cargo Weight Rating (CWR) is the maximum
weight of the load your vehicle can carry. It doesn't
include the weight of the people inside. But, you
can ®gure about 150 lbs. (68 kg) for each seat.
The total cargo load must not be more than your
vehicle's CWR.
Refer to the Truck-Camper Loading Information label in
glove box for dimensions A and B as shown in the
following illustration.Use the rear edge of the load ¯oor for measurement
purposes. The recommended location for the cargo
center of gravity is at point C for the CWR. It is the point
where the mass of a body is concentrated and, if
suspended at that point, would balance the front and rear.
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Here is an example of proper truck and camper match:
A. Camper Center of Gravity
B. Recommended Center of Gravity Location Zone
The camper's center of gravity should fall within the
center of gravity zone for your vehicle's cargo load.
You must weigh any accessories or other equipment
that you add to your vehicle. Then, subtract this
extra weight from the CWR. This extra weight may
shorten the center of gravity zone of your vehicle. Your
dealer can help you with this.
If your slide-in camper and its load weighs less than the
CWR, the center of gravity zone for your vehicle may
be larger.Your dealer can help you make a good vehicle-camper
match. He'll also help you determine your CWR.
After you've loaded your vehicle and camper, drive to a
weigh station and weigh the front and rear wheels
separately. This will tell you the loads on your axles.
The loads on the front and rear axles shouldn't be more
than either of the GAWRs. The total of the axle loads
should not be more than the GVWR.
Open your driver's door and look at the Certi®cation/Tire
label to ®nd out your GAWR and GVWR.
If you've gone over your weight ratings, move or take
out some things until all the weight falls below the
ratings. Of course, you should always tie down any
loose items when you load your vehicle or camper.
When you install and load your slide-in camper, check
the manufacturer's instructions.
If you want more information on curb weights, cargo
weights, Cargo Weight Rating and the correct center of
gravity zone for your vehicle, your dealer can help
you. Just ask for a copy of²Consumer Information,
Truck-Camper Loading.²
4-69