2001 GMC SIERRA Owner's Manual

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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's 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
tire/certification label.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
A=front axle
W.B.=Vehicle Wheelbase

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For 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 this
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 more
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.
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't 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.

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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's 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 weight station and weigh your
vehicle. Your dealer can also help you with this.
See your dealer for additional advice and information
about using a snow plow on your vehicle. Also, see
ªLoading Your Vehicleº earlier in this section.
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

everything else added to the camper after it left
the factory,

everything in the camper and

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
figure about 150 lbs. (68 kg) for each seat.
The total cargo load must not be more than your
vehicle's CWR.

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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 floor 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.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.

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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
Certification/Tire label to find 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 of ªConsumer Information,
Truck
-Camper Loading.º
Trailer Recommendations
You must subtract your hitch loads from the CWR
for your vehicle. Weigh your vehicle with the trailer
attached, so that you won't go over the GVWR or
GAWR. If you are using a weight
-distributing hitch,
weigh the vehicle without the equalizer bars in place.
You'll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, see ªTrailer Towingº in
the Index.
Camper Wiring Harness
(If Equipped)
If your vehicle is equipped with a camper wiring
harness, see ªTrailer Wiring Harnessº in the Index
for further information.

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Pickup Conversion to Chassis Cab
General Motors is aware that some vehicle owners
may consider having the pickup box removed and a
commercial or recreational body installed. Before you
do so, first contact the GM Customer Assistance
Office for your area for information on such conversions
specific to this vehicle. See the ªWarranty and Owner
Assistanceº booklet for Customer Assistance Office.
Owners should be aware that, as manufactured, there
are differences between a chassis cab and a pickup
with the box removed which may affect vehicle safety.
The components necessary to adapt a pickup to permit
its safe use with a specialized body should be installed
by a body builder in accordance with the information
available from the Customer Assistance Office.
Towing a Trailer
CAUTION:
If you don't use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example, if the trailer is too heavy,
the brakes may not work well
-- or even at all.
You and your passengers could be seriously
injured. Pull a trailer only if you have followed
all the steps in this section. Ask your dealer for
advice and information about towing a trailer
with your vehicle.

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NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered by
your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer
with your vehicle. Additional rear rear axle
maintenance is required for a vehicle used to tow
a trailer. See ªScheduled Maintenance Servicesº
in the Index.
To identify what the vehicle trailering capacity is for
your vehicle, you should read the information in
ªWeight of the Trailerº that appears later in this section.
If yours was built with trailering options, as many are,
it's ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.That's the reason for this part. In it are many time
-tested,
important trailering tips and safety rules. Many of these are
important for your safety and that of your passengers. So
please read this section carefully before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:

There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but
also where you'll be driving. A good source for this
information can be state or provincial police.

Consider using a sway control if your trailer will
weigh less than the capacity stamped on your step
bumper. You should always use a sway control
if your trailer will weigh more than the capacity
stamped on your step bumper. You can ask a
hitch dealer about sway controls.

Don't tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.

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Then, during the first 500 miles (800 km) that you
tow a trailer, don't drive over 50 mph (80 km/h) and
don't make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at the
heavier loads.

If you have an automatic transmission, you can
tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or, if necessary, a lower
gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
If you have a manual transmission and you are
towing a trailer, it's better not to use FIFTH (5)
gear. Just drive in FOURTH (4) gear (or, as you
need to, a lower gear). See ªTow/Haul Modeº
in the Index.
Three important considerations have to do with weight:

the weight of the trailer,

the weight of the trailer tongue

and the weight on your vehicle's tires.Tow/Haul Mode (If Equipped)
Tow/haul is a feature on automatic transmission
equipped vehicles that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
tow/haul mode is to:

Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer
or a large or heavy load.

Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when the
vehicle is unloaded.

Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Automatic transmission equipped vehicles are provided
with a button at the end of the shift lever which when
pressed enables tow/haul. When the button is pressed,
a light on the instrument panel will illuminate to indicate
that tow/haul has been selected. Tow/haul may be turned
off by pressing the button again, at which time the
indicator light on the instrument panel will turn off.
The vehicle will automatically turn off tow/haul every
time it is started.