1999 GMC SIERRA spare wheel

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Off-Road Driving with Your
Four
-Wheel-Drive Vehicle
This off-road guide is for vehicles that have
four
-wheel drive.
Also, see ªAnti
-Lock Brakesº in the Index.
If your vehicle doesn't have four
-wheel drive, you
shouldn't drive off
-road unless you're on a level,
solid surface.
Off
-road driving can be great fun. But it does have some
definite hazards. The greatest of these is the terrain itself.
ªOff
-roadingº means you've left the great North
American road system behind. Traffic lanes aren't
marked. Curves aren't banked. There are no road signs.
Surfaces can be slippery, rough, uphill or downhill. In
short, you've gone right back to nature.
Off
-road driving involves some new skills. And that's
why it's very important that you read this guide. You'll
find many driving tips and suggestions. These will help
make your off
-road driving safer and more enjoyable.
Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance and
service work done. Check to make sure all underbody
shields (if so equipped) are properly attached.
Be sure you read all the information about your
four
-wheel-drive vehicle in this manual. Is there enough
fuel? Is the spare tire fully inflated? Are the fluid levels
up where they should be? What are the local laws that
apply to off
-roading where you'll be driving? If you
don't know, you should check with law enforcement
people in the area. Will you be on someone's private
land? If so, be sure to get the necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.

The heaviest things should be on the load floor and
forward of your rear axle. Put heavier items as far
forward as you can.

Be sure the load is secured properly, so driving on
the off
-road terrain doesn't toss things around.

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5-22
A. Hoist Assembly
B. Ratchet
C. Jack Handle
D. Hoist ShaftE. Valve Stem,
Pointed Down
F. Spare Tire
G. Retainer
H. Hoist CableFollow these instructions to lower the spare tire:
1. One side of the ratchet has an UP marking. The other
side has a DOWN marking. Assemble the ratchet to
the hook near the end of the jack handle (as
illustrated) with the DOWN marking facing you.
Insert the other end through the hole in the rear
bumper and into the hoist shaft.
2. Turn the ratchet to lower the spare tire to the ground.
Continue to turn the ratchet until the spare tire can be
pulled out from under the vehicle.
3. When the tire has been lowered, tilt the retainer at
the end of the cable so it can be pulled up through
the wheel opening.
4. Put the spare tire near the flat tire.

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5-25 Removing the Flat Tire and Installing
the Spare Tire
1. Use the ratchet and
wheel wrench to loosen
all the wheel nuts.
Turn the wheel wrench
counterclockwise,
with DOWN facing
you, to loosen the wheel
nuts. Don't remove the
wheel nuts yet.
2. Position the jack under the vehicle. If the flat tire is
on the front of the vehicle, position the jack on the
frame behind the flat tire. If the flat tire is on the
rear, position the jack on the rear axle between the
spring and the shock absorber.
CAUTION:
Getting under a vehicle when it is jacked up is
dangerous. If the vehicle slips off the jack, you
could be badly injured or killed. Never get under
a vehicle when it is supported only by a jack.
CAUTION:
Raising your vehicle with the jack improperly
positioned can damage the vehicle and even make
the vehicle fall. To help avoid personal injury and
vehicle damage, be sure to fit the jack lift head
into the proper location before raising the vehicle.

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Front Position Rear Position
3. With UP on the ratchet facing you, raise the vehicle
by rotating the ratchet and wheel wrench clockwise.
Raise the vehicle far enough off the ground so there
is enough room for the spare tire to fit.
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.

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NOTICE:
Improperly tightened wheel nuts can lead to
brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque specification.
9. Put the wheel trim back on. For vehicles with plastic
wheel nut caps, tighten the caps until they are
finger
-tight, then tighten them an additional one-half
of a turn with the ratchet and wheel wrench.
Storing a Flat or Spare Tire and Tools
CAUTION:
Storing a jack, a tire or other equipment in the
passenger compartment of the vehicle could
cause injury. In a sudden stop or collision, loose
equipment could strike someone. Store all these
in the proper place.
Store the flat tire where the spare tire was stored.

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5-30
For an underbody spare tire carrier, store the tire under
the rear of the vehicle in the spare tire carrier. To store
the tire:
1. Put the tire on the ground at the rear of the vehicle
with the valve stem pointed down 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 ratchet, with the UP mark facing you,
near the hook at the end of the jack handle. Insert the
other end, on an angle, through the hole in the rear
bumper and into the hoist shaft.
4. Raise the tire fully against the underside of the
vehicle. Continue turning the ratchet until there are
two ªclicksº or ªratchets.º The spare tire hoist
cannot be over
-tightened.
5. Grasp and push against the tire to be sure it is stored
securely and does not move.
A. Hoist Assembly
B. Ratchet
C. Jack Handle
D. Hoist ShaftE. Valve Stem,
Pointed Down
F. Flat or Spare Tire
G. Retainer
H. Hoist Cable
Return the jack, ratchet, wheel wrench and jack
extensions to their location behind the passenger's seat.
Secure the items and replace the jack cover, if there
is one.

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When to Check
Check your tires once a month or more. Also, check the
tire pressure of the spare tire.
How to Check
Use a good quality pocket
-type gage to check tire
pressure. You can't tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they're underinflated.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
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. If your vehicle has dual rear wheels, also
see ªDual Tire Operationº later in this section.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, always use one of
the correct rotation patterns shown here when rotating
your tires.
If your vehicle has front tires with different load ranges
or tread designs (such as all season vs. on/off road) than
the rear tires, don't rotate your tires front to rear.

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6-55 Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel nut is replaced, check the wheel nut torque
after 100, 1,000 and 6,000 miles (160, 1 600 and
10 000 km) of driving. For proper torque, see ªWheel
Nut Torqueº in the Index.
The outer tire on a dual wheel setup generally wears
faster than the inner tire. Your tires will wear more
evenly and last longer if you rotate the tires periodically.
If you're going to be doing a lot of driving on
high
-crown roads, you can reduce tire wear by adding
5 psi (35 kPa) to the tire pressure in the outer tires.
Be sure to return to the recommended pressures when no
longer driving under those conditions. See ªChanging a
Flat Tireº in the Index for more information.
CAUTION:
If you operate your vehicle with a tire that is
badly underinflated, the tire can overheat. An
overheated tire can lose air suddenly or catch
fire. You or others could be injured. Be sure
all tires (including the spare, if any) are
properly inflated.
Buying New Tires
To find out what kind and size of tires you need, look at
the Certification/Tire label.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire's sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service on
your vehicle. If your tires have an all
-season tread
design, the TPC number will be followed by an ªMSº
(for mud and snow).