2001 GMC SIERRA ECU

4-47
Loading Your Vehicle
The Certification/Tire label is found on the rear edge of
the driver's door or in the Incomplete Vehicle Document
in the cab.
The label shows the size of your original tires and the
inflation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the GVWR
(Gross Vehicle Weight Rating). The GVWR includes
the weight of the vehicle, all occupants, fuel and cargo.The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find 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 Certification/Tire label also contains information
about your Front Axle Reserve Capacity. See ªFront
Axle Reserve Capacityº later in this section.
And, if you do have a heavy load, you should spread
it out.
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.

4-48
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.
Your warranty does not cover parts or components that
fail because of overloading.
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.

Don't leave an unsecured child restraint
in your vehicle.

When you carry something inside the
vehicle, secure it whenever you can.

Don't 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 Drivingº in the Index.

4-50

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've got other equipment already adding to the
weight of your vehicle.
Here are some guidelines for safely carrying a
snow plow on your vehicle:

Make sure the weight on the front and rear axles
doesn't 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 won't 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.

4-74
Before you start, check the trailer hitch and platform
(and attachments), safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer has
electric brakes, start your vehicle and trailer moving and
then apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.
While towing a trailer or when exposed to long periods
of sunshine, the floor of the truck bed may become very
warm. Avoid putting items in the truck bed that might be
affected by high ambient temperatures.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require heavy
braking and sudden turns.
Passing
You'll need more passing distance up ahead when
you're towing a trailer. And, because you're a good deal
longer, you'll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that
hand to the left. To move the trailer to the right, move
your hand to the right. Always back up slowly and,
if possible, have someone guide you.
Making Turns
NOTICE:
Making very sharp turns while trailering could
cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you're turning with a trailer, make wider turns than
normal. Do this so your trailer won't strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.

5-27
Rear Position
3. Make sure the jack head is positioned so that the rear
axle is resting securely between the grooves that are
on the jack head. Turn the wheel wrench clockwise
to raise the vehicle. Raise the vehicle far enough off
the ground so there is enough room for the spare tire
to fit under the wheel well.
4. Remove all the wheel
nuts and take off the
flat tire.
5. Remove any rust or dirt
from the wheel bolts,
mounting surfaces and
spare wheel.

5-32
Return the bottle jack, wheel blocks, wheel wrench and
jack extensions to their location behind the passenger's
seat. Secure the items in the vehicle as shown.
A. Wing Nut
B. Wheel Blocks
C. Wheel Wrench and
Extensions Retainer
D. GlovesE. Wheel Wrench
and Extensions
F. Storage Bag
G. Bottle Jack Holder
H. Bottle Jack
I. Wheel Block
RetainerStore the tire under the rear of the vehicle in the spare
tire carrier. To store the tire, do the following:
1. Put the tire on the ground at the rear of the
vehicle with the valve stem pointed downward
and to the rear.
2. Tilt the retainer downward and through the wheel
opening. Make sure that the retainer is fully seated
across the underside of the wheel.
3. Attach the wheel wrench and extensions together.
Insert the hoist end through the hole in the rear
bumper and into the hoist shaft.
4. Raise the tire part of the way upward. When the tire
is almost in the stored position, adjust the tire so that
the valve stem is toward the rear of the vehicle.

5-33
A. Hoist Assembly
B. Wheel Wrench
C. Extensions
D. Hoist ShaftE. Valve Stem,
Pointed Down
F. Flat or Spare Tire
G. Retainer
H. Hoist Cable
5. Raise the tire fully against the underside of the
vehicle. Continue turning the wheel wrench until the
tire is secure and the cable is tight. The spare tire
hoist cannot be overtightened.
6. Make sure the tire is stored securely. Push, pull, and
then try to rotate or turn the tire. If the tire moves,
use the wheel wrench/hoist shaft to tighten the cable.
Replace the jack, tools and spare tire lock.

6-54 Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km). Any time you notice unusual
wear, rotate your tires as soon as possible and check
wheel alignment. Also check for damaged tires or
wheels. See ªWhen It's Time for New Tiresº and
ªWheel Replacementº later in this section for more
information. Make sure the spare tire is stored securely.
Push, pull, and then try to rotate or turn the tire.
If it moves, use the wheel wrench/hoist shaft to tighten
the cable. See ªStoring a Flat or Spare Tire and Toolsº
in the Index.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See ªScheduled
Maintenance Servicesº in the Index for scheduled
rotation intervals.
If your vehicle has single rear wheels and the tread
design for your front tires is the same as your rear tires,
always use one of the correct rotation patterns shown
here when rotating your tires.
If your vehicle has front tires with different tread designs
(such as all season vs. on/off road) than the rear tires,
don't rotate your tires front to rear.