1997 GMC SIERRA tires

.............. .............
I
What’s the worst time for this? “Wet ice.” Very cold
snow or ice can be slick and hard to drive on. But wet
ice can be even more trouble because it may offer the
least traction of all. You can get wet ice when it’s about
freezing
(32°F; 0°C) and freezing rain begins to fall.
Try to avoid driving on wet ice until salt and sand crews
can get there.
.,
..
Whatever the condition -- smooth ice, packed, blowing
or loose snow
-- drive with caution.
Accelerate gently.
Try not to break the fragile traction. If
you accelerate too fast, the drive wheels will spin and
polish the surface under the tires even more.
Your anti-lock brakes improve your vehicle’s stability
when you make a hard stop on a slippery road. Even
though you have an anti-lock braking system, you’ll
want to begin stopping sooner than you would on
dry
pavement. See “Anti-Lock” in the Index.
Mow greater following distance on any slippery road.
Watch for slippery spots. The road might be fine
until you hit a spot that’s covered with
ice. On an
otherwise clear road, ice patches may appear in
shaded areas where the sun can’t reach: around
clumps of trees, behind buildings or under bridges.
Sometimes the surface
of a curve or an overpass may
remain icy when the surrounding roads are clear. If
you see a patch
of ice ahead of you, brake before you
are on it.
Try not to brake while you’re actually on
the ice, and avoid sudden steering maneuvers.
4-38
ProCarManuals.com

Loading Your Vehicle
I-
GAWR FRT
RIM COLD TIRE PRESSURE
-!=2 - I
The Certificationrnire 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 Certificationmire 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.
And, if you do have a heavy load, you should spread
it out.
/;1 CAUTION:
In the case of a den 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.
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.
4-41
ProCarManuals.com

a If you have an automatic transmission, you can tow
in OVERDRIVE (@). 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).
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.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. And, it can also depend
on any special
equipment that you have on your vehicle. Use
one of the following charts to determine how much
your vehicle can weigh, based upon your vehicle model
and options.
Maximum trailer weight is calculated assuming the
driver and one passenger are in the tow vehicle and it
has all
the required trailering equipment. The weight of
additional optional equipment, passengers and cargo in
the tow vehicle must be subtracted from the maximum
trailer weight.
Above the
2,000 lbs. (908 kg) trailer rating, the engine
oil cooler is required
on C/K-1500 and C/K-2500
models with gas engines. Refer to the Trailering Guide
for oil cooler recommendations.
Above the
5,000 lbs. (2 270 kg) trailer rating, heavy-duty
or gas shock absorbers are required on
C- 1500 models,
and heavy-duty shock absorbers or the off-road chassis
package are required on
K- 1500 models.
4-47
ProCarManuals.com

A B
If you’re using a weight-carrying hitch, the trailer
tongue
(A) should weigh 10 percent of the total loaded
trailer weight
(B). If you’re using a weight-distributing
hitch, the trailer tongue
(A) should weigh 12 percent of
the total loaded trailer weight (B).
After you’ve loaded your trailer, weigh the trailer and
then
the tongue, separately, to see if the weights are
proper. If they aren’t,
you may be able to get them right
simply by moving some items around
in the trailer.
Total Weight on Your Vehicle’s Tires
Be sure your vehicle’s tires are inflated to the upper
limit for cold tires. You’ll find these numbers on the
Certification label at the rear edge
of the driver’s door or
see “Tire Loading”
in the Index. Then be sure you don’t
go over the GVW limit for your vehicle, including the
weight of the trailer tongue.
Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads are a
few reasons why
you’ll need the right hitch. Here are
some rules to follow:
0 If you use a step-bumper hitch, your bumper could
be damaged in sharp turns. Make sure
you have
ample room when turning
to avoid contact between
the trailer and the bumper.
0 If you’ll be pulling a trailer that, when loaded, will
weigh more than
the capacity stamped on your step
bumper, be sure
to use a properly mounted,
weight-distributing hitch and sway control of the
proper size. This equipment
is very important for
proper vehicle loading and good handling when
you’re driving.
4-53
ProCarManuals.com

Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the tongue
of the trailer so that the tongue will not drop to the road
if it becomes separated from
the hitch. Instructions
about safety chains may be provided by the hitch
manufacturer or by the trailer manufacturer. Follow the
manufacturer’s recommendation for attaching safety
chains and do not attach them to
the bumper. Always
leave just enough slack
so you can turn with your rig.
And, never allow safety chains to drag on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 Ibs. (450 kg)
loaded, then it needs its own brakes
-- and they must be
adequate. Be sure
to read and follow the instructions for
the trailer brakes
so you’ll be able to install, adjust and
maintain them properly.
Your trailer brake system can tap into the vehicle’s
hydraulic brake system
only if:
The trailer parts can withstand 3,OOO psi (20 650 Wa)
of pressure.
The trailer’s brake system will use less than 0.02
cubic inch (0.3 cc) of fluid from your vehicle’s
master cylinder. Otherwise, both braking systems
won’t work well.
You could even lose your brakes.
If everything checks out this far, make the brake tap at the
port on the master cylinder that sends the fluid to the rear \
brakes. But don’t use copper tubing for this.
If you do, it
will bend and finally break off. Use steel brake tubing.
Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the
trailer. And always keep
in mind that the vehicle you are
driving is now a
good deal longer and not nearly as
responsive as your vehicle
is by itself.
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.
4-54
ProCarManuals.com

10. Try to start the vehicle with the dead battery.
If it won’t start after a few tries, it probably
needs service.
11. Remove the cables in reverse order to prevent
electrical shorting. Take care that they don’t touch
each other or any other metal.
A. Heavy Metal Engine Part
B. Good Battery
C. Dead Battery
Towing Your Vehicle
Try to have your GM dealer or a professional towing
service tow your vehicle. See “Roadside Assistance”
in
the Index.
If your vehicle has been changed since it was
factory-new, by adding such things as fog lamps, aero
skirting, or special tires and wheels, these instructions
may not be correct.
Before you do anything, turn on the hazard
warning flashers.
When you call, tell the towing service:
0 That your vehicle has rear-wheel drive, or that it has
the four-wheel-drive option.
0 The make, model and year of your vehicle.
0 Whether you can move the shift lever for the
0 If there was an accident, what was damaged.
transmission and transfer
case, if you have one.
When the towing service arrives, let the tow operator
know that this manual contains detailed towing
instructions and illustrations. The operator may want to
see them.
5-8
ProCarManuals.com

Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spi.ns faster to provide
more air
to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves
fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer towing and/or high outside temperatures, the fan speed
increases as the clutch more fully engages.
So you may
hear an increase in fan noise. This
is normal and should
not be mistaken as the transmission slipping or making
extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional
cooling is not required and the clutch disengages.
You may also hear this
fan noise when you start the engine.
It will
go away as the fan clutch partially disengages.
If a Tire Goes Flat
It’s unusual for a tire to “blow out” while you’re driving,
especially
if you maintain your tires properly. If air goes
out
of a tire, it’s much more likely to leak out slowly.
But if you should ever have
a “blowout,” here are a
few tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in
a skid. In any rear blowout, remove your foot from
the accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but
you can still steer. Gently
brake
to a stop -- well off the road if possible.
If a tire goes flat, the next part shows how to
use your
jacking equipment
to change a flat tire safely.
ProCarManuals.com

C
E
I
F
Chassis Cab Models
A. Nut
B. Retainer
C. Jack Handle
Extension
D. Jack Handle Extension
E. Wheel Wrench
E Jack and Tool
Storage Box
G. Ratchet
H. Jack Handle
I. Tool Retainer
J. Jack
If You’re Stuck: In Sand, Mud,
Ice or Snow
What you don’t want to do when your vehicle is stuck is
to spin your wheels too fast. The method known
as
“rocking” can help you get out when you’re stuck, but
you must use caution.
’ A CAUTION: I I
If you let your tires spin at high speed, they can
explode, and you or others could be injured.
And, the transmission or other parts
of the
vehicle can overheat. That could cause an engine
compartment fire or other damage. When you’re
stuck, spin the wheels
as little as possible. Don’t
spin the wheels above
35 mph (55 kmlh) as shown
on the speedometer.
5-34
ProCarManuals.com