GMC SIERRA 1994 Owners Manual

Tires
We don’t make tires. Your new vehicle comes with high quality tires made
by a leading tire manufacturer. These tires
are warranted by the tire
manufacturers and their warranties are delivered with
every new vehicle. If
your spare tire is a different brand than your road tires, you will have a tire
warranty folder from each of these manufacturers.
Inflation - Tire Pressure
The Certificatioflire label which is on the rear edge of the driver’s door, or
on the incomplete vehicle document in the cab, shows the correct inflation
pressures for your tires, when they’re cold. “Cold” means your vehicle has
been sitting for at least three hours or driven no more than a mile.
You can operate some vehicles at reduced inflation pressures only when
you’ll be carrying reduced loads. On those vehicles, the minimum cold
inflation pressures for a typical reduced load are printed on the “Improved
Ride Tire Pressure’’ label located on the driver’s door. Weigh the vehicle to
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find the load on each tire and see the label for the minimum cold inflation
pressures
for that load.
NOTICE:
Don’t let anyone tell you that underinflation or overinflation is
all right. It’s not. If your tires don’t have enough air
(underinflation) you can get:
Too much flexing
Too much heat
Tire overloading
Bad wear
Bad handling
Bad fuel economy.
If your tires have too much air (overinflation), you can get:
Unusual wear
Bad handling
Rough ride
‘Needless damage from road hazards.
When io 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. Simply looking
at the tires
will not tell you the pressure, especially if you have radial tires
- which may look properly inflated even if they’re underinflated.
If your tires have valve caps, be sure to put them back on. They help prevent
leaks by keeping out dirt and moisture.
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Special Tire lnflation
If you have 16 inch tires on your vehicle, and:
- You’ll be driving for very long at speeds of 66 mph (105 km/h) to
75 mph (120
km/h) where legal, inflate tires to 10 psi (70 kPa)
more than the recommended cold inflation pressures.
- You’ll be driving for very long at speeds of 76 mph (120 km/h) to
85 mph (135
km/h) where legal, cold inflation pressures should be
increased by
10 psi (70 kPa) and you must also reduce axle load
capacity by 10%.
Do not drive over 85 mph (135 km/h) even if
it’s legal.
Inflation pressures should never exceed 10 psi (70 kPa) above the
inflation specified for the maximum load of the tire.
If you have 19.5 inch radial tires on your vehicle, and:
- You’ll be driving for very long at speeds of 66 mph (105 km/h) to
70 mph (110 km/h) where legal, inflate tires to 5 psi (35 kPa) more
than the recommended cold inflation pressures, and reduce the
axle load capacity by 4%.
- You’ll be driving for very long at speeds of 7 1 mph (1 15 km/h) to
75 mph (120
km/h) where legal, cold inflation pressures should be
increased by 5 psi (35 kPa) and you must also reduce axle \
load capacity by 12%.
Do not drive over 75 mph (120 km/h) even if
it’s legal.
Inflation pressures should never exceed 20 psi (140 kPa) above the
inflation specified for the maximum load of the tire.
Tire Inspection and Rotation
To make your tires last longer, have them inspected and rotated at the
mileages recommended in the Maintenance Schedule. See “Scheduled
Maintenance Services” in the Index.
FRT
8
FRT
Use this rotation
pattern.
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If your vehicle has front tires with different load ratings or tread designs
(such
as all season vs. on/off road) than the rear tires, don’t rotate your tires
front
to rear.
After the tires have been rotated, adjust the front and rear inflation pressure
as shown on the CertificatiodTire label. Make certain that all wheel nuts are
properly tightened. See “Wheel
Nut Torque” in the Index.
A CAUTION:
Rust or dirt on a wheel, or on the parts to which it is fastened,
When It’s Time for New Tires
TREAD WEAR
INDICATORS
One way to tell when
it’s time for
new tires
is to check the
treadwear indicators,
which
will appear
when your tires have
only
2/32 inch (1.6
mm) or less of tread
remaining.
You need a
new tire if:
0 You can see the indicators at three or more places around the tire.
0 You can see cord or Fabric showing through the tire’s rubber.
0 The tread or sidewall is cracked, cut or snagged deep enough to show
cord or fabric.
The tire has a bump, bulge or split.
The tire has a puncture, cut, or other damage that can’t be repaired well
because
of the size or location of the damage.
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Dual Tire Rotation
n
Use one of these
patterns if you have
the same tire sizes and
load ranges on
the
front and rear.
Use
this pattern if
your front and rear
tires are different sizes
or load ranges. The
dual rear tires are
rotated
as a pair and
the inside rear tires
become the outside
rear tires.
When you install dual wheels, be sure
the vent holes in the wheels are lined
UP.
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Dual lire Operation
If your vehicle has dual rear wheels, the outer tire will usually wear 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.
Buying New Tires
To find out what kind and size of tires you need, look at the
CertificationRire 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 a
“MS” (for mud and snow).
If you ever replace your tires with those not having
a TPC Spec number,
make sure they are
the same size, load range, speed rating and construction
type (bias, bias-belted or radial) as your original tires.
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Uniform Tire Quality Grading
The following information relates to the system developed by the Un\
ited
States National Highway Traffic Safety Administration which grade\
s tires
by treadwear, traction and temperature performance. (This applie\
s only to vehicles sold in the United States.)
Treadwear
The treadwear grade is a comparative rating based on the wear rate of the
tire when tested under controlled conditions on a specified gov\
ernment test
course. For example, a tire graded
150 would wear one and a half (1 1/2)
times as well on the government course as a tire graded 100. The relative
performance of tires depends upon the actual conditions of their use,
however, and may depart significantly from the norm due to variations in
driving habits, service practices and differences in road charac\
teristics and
climate.
Traction -A, B, C
The traction grades, from highest to lowest are: A, B, and C. They represent
the tire’s ability to stop on wet pavement as measured under controlled
conditions on specified government test surfaces of asphalt and concrete. A
tire marked
C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking
(straight-ahead) traction tests and does not include cornering \
(turning)
traction.
Temperature - A, B, C
The temperature grades are A (the highest), B, and C, representing the tire’s
resistance to the generation of heat and its ability to dissipate heat when
tested under controlled conditions on a specified indoor laborat\
ory test
wheel. Sustained high temperature can cause the material of the tire to
degenerate and reduce tire life, and excessive temperature can \
lead to
sudden.tire failure. The grade
C corresponds to a level of performance
which all passenger car tires must meet under the Federal Motor Vehicle
Safety Standard
No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the minimum required by
law.
Warning: The temperature grade for
this tire is established for a tire that is
properly inflated ad not overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination, can cause heat
buildup and possible tire failure.
These grades are molded on the sidewalls
of passenger car tires.
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While the tires available as standard or optional equipment on General
Motors vehicles may vary with respect
to these grades, all such tires meet
General Motors performance standards and have been approved for use on
General Motors vehicles. All passenger type
(P Metric) tires must conform
to Federal safety requirements in addition to these grades.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced carefully at the
factory
to give you the longest tire life and best overall performance.
In most cases,
you will not need to have your wheels aligned again.
However,
if you notice unusual tire wear or your vehicle pulling one way or
the other, the alignment may need to be reset. If
you notice your vehicle
vibrating when driving on
a smooth road, your wheels may need to be
rebalanced.
Wheel Replacement
Repla@ Zm wheel that is bent, cracked or badly rusted. If wheel nuts keep
coming loose, the wheel, wheel bolts, and wheel nuts should be replaced. If
the wheel leaks air, replace it (except some aluminum wheels, which can
sometimes be repaired). See your GM dealer if any of these conditions exist.
Your dealer will know
the kind of wheel you need.
Each new wheel should have the same load carrying capacity, diameter,
width, offset, and be mounted the same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts, or wheel nuts,
replace them only with new GM original equipment parts. This way,
you
will be sure to have the right wheel, wheel bolts, and wheel nuts for your
GM model.
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NOTICE:
The wrong wheel can also cause problems with bearing life,
brake cooling, speedometer/odometer calibration, headlight aim,
bumper height, vehicle ground clearance, and tire or tire chain
clearance to the body and chassis.
Used Replacement Wheels
Tire Chains
NOTICE:
If your vehicle has dual wheels or LT26Y75R16 size tires, don’t
use tire chains; they can damage your vehicle.
If you don’t have
dual wheels or
if you have a tire size other than LT265/75R16,
use tire chains only where legal and only when you must. Use
only SAE Class “S” type chains that are the proper size for your
tires. Install them on the tires of the rear axle. Tighten them as
tightly
as possible with the ends securely fastened. Drive slowly
and follow the chain manufacturer’s instructions.
If you can
hear the chains contacting your vehicle, stop and retighten them.
If the contact continues, slow down until it stops. Driving too
fast with chains on will damage your vehicle.
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Appearance Care
Remember, cleaning products can be hazardous. Some are toxic. Others can
burst into flame if you strike a match or get them on a hot
part of the
vehicle. Some are dangerous if you breathe their fumes in a closed space.
When you use anything from a container to clean your vehicle, be sure
to
follow the manufacturer's warnings and instructions. And always open your
doors or windows when you're cleaning the inside.
Never use these to clean your vehicle:
0 Gasoline
0 Benzene
0 Naphtha
0 Carbon Tetrachloride
0 Acetone
0 Paint Thinner
0 Turpentine
0 Lacquer Thinner
0 Nail Polish Remover
They can all be hazardous
- some more than others - and they can all
damage your vehicle, too.
NOTICE:
Don't use any of these unless this manual says you can. In many
uses, these will damage your vehicle:
0 Laundry Soap
Bleach I
Reducing Agents
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