1993 GMC SIERRA service

Service & Appearance Care
A Do not load your vehicle any heavier than the GWR or the
- b maximum front and rear GAWRs. If you do, parts on your vehicle
can break, or it can change the way your vehicle handles. These
could cause you to lose control.
Also, overloading can shorten the
life
of your vehicle.
Using heavier suspension components to get added durability migh\
t not
change your weight ratings. Ask your dealer to help you load \
your vehicle the right way.
.,ur warranty does
nnt cover par nr componentg that fail becausl
overloading.
If you put things inside your vehicle-like suitcases, tools, packag\
es, or
anything else-they will 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.
* Things you put inside your vehicle can strike and injure peopl\
e in a
9 Put things in the cargo area of your vehicle. Try to spread the
9 Never stack heavier things, like suitcases, inside the vehicle so
d sudden stop or turn, or in a crash.
weight evenly.
that some
of them are above the tops of the seats.
When you
carry something inside the vehicle, secure it
whenever you can.
Don’t have a seat folded down unless you need to.
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,. *.
’
Service & Appearance Care
Truck-Camper Loading Information
Open your glove box door and look for this label:
PO338
This label will tell you how much of a load your vehicle can carry, and how
to spread out your load the right way.
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.
I ne Cargo Weight Rating (CWR) is the maximum weight of the l\
oad your
vehicle can carry. It doesn’t include the weight of the people inside. But, you
can figure about
150 pounds for each seat.
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Service & Appearance Care
Trailer Recommendations
You must subtract your hitch loads from the CWR for your vehicle. Weigh
your vehicle with your trailer attached,
so that you won’t go over the GVWR
or the GAWR.
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 “Trailer Towing” in the Index.
If you want more information on curb weights, cargo weights, cargo wei\
ght
rating and the correct center of gravity zone for your vehicle, your dealer can
help you. Just ask for a copy of “Consumer Information, Truck-Cam\
per
Loading.”
Pickup Conversion lo. 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 Zone Office for your area for information on
such conversions. (See the “Warranty and Owner Assistance”\
booklet for
Zone Office.) Owners should be aware that, as manufactured, th\
ere are
differences between a chassis cab and a pickup with the box r\
emoved which may affect vehicle safety. The components necessary to adapt the pickup to
permit its safe use with a specialized body should be installed by a bod\
y
builder in accordance with the information available from the Z\
one Office.
Tires
We don’t make tires. Your new vehicle comes with high quali\
ty 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.
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Service & Appearance Care
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.
Simply looking at the tires will not tell you the pressure, e\
specially
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.
Special Tire Inflation
If you have 16 inch tires on your vehicle, and:
- You’ll be driving for very long at speeds of 66 mph (1 05 km/h) to 75
mph (120 kmlh) where legal, inflate tires 10 psi (70 kPa) more than
the recommended cold inflation pressure.
- You’ll be driving for very long at speeds of 76 mph (120 kmlh) to 85
mph (1 35 km/h) where legal, cold inflation pressure 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 kdh) even if
it’s legal.
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Service & Appearance Cam
Tire lnspecfion 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.
Q
-
-
K2655
Use this rotation pattern.
If your vehicle has front tires with different load ratings or tread designs (such
as all season
vs. onloff 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 CertificationRire label. Make certain that all wheel nuts are
properly tightened. See “Wheel Nut Torque”
in the Index.
A Rust or dirt on a wheel, or on the parts to which -it is fastened, can
make the wheel nuts become loose after a time. The wh.eel could
come
off and cause an accident. When you change- a- :wheel, remove
’ any -rust or dirt from places where the wheel attaches to the vehicle:
,: In an emergency, you can use a cloth or paper towel to do this; but
3 be sure to use a scraper or wire brush later, if you need- to, to get
-T all the rust or dirf off. See “Changing a Flat Tire” in the Index.
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Service & Appearance Cam
When It’s Time for New Tires
K1656
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:
You can see the indicators at three places around the tire.
You can see cord or fabric showing through the tire’s rubber.
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 repalred well
because of the size or location of the damage.
Dual Tire 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.
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r CAUTION I
If you operate your vehicle with a tire that is badly underinflated, the
tire can overheat. An overheated tire can lose air suddenly or catcl.
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 Certificationflire
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 num\
ber. That
way, your vehicle will continue to have tires that are designed to give proper
endurance, handling, speed rating, traction, ride and other thin\
gs 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.
1 CAUTION
* Mixing tires could cause you to lose control while driving. If you mix
vehicle may not handle properly, and you could have a crash. Be
- ) tires of different sizes or types (radial and bias-belted tires), the
I sure to use the same size and type tires on all wheels. I
Uniform Tire Qua/ity Grading
The following information relates to the system developed by the United
States National Highway Traffic Safety Administration which grade\
s tires by
treadwear, traction and temperature performance. (This applies o\
nly 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 governmen\
t 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 var\
iations in
driving habits, service practices and differences in road characteristics and
climate.
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Service & Appearance Care
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 and not overloaded. Excessive speed, underinfla\
tion, or
excessive loading, either separately or in combination, can caus\
e heat buildup
and possible tire failure.
These grades are molded on the sidewalls of passenger car tire\
s. 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 AIignment 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.
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