1997 GMC SIERRA manual transmission

Driving Downhill
When off-roading takes you downhill, you 11 want to
consider
a number of things:
How steep is the downhill? Will I be able to maintain
What’s the surface like? Smooth? Rough? Slippery?
Are there hidden surface obstacles? Ruts? Logs?
What’s at the bottom of the hill? Is there a hidden
vehicle control?
Hard-packed dirt? Gravel?
Boulders?
creek bank or even a river bottom with large rocks?
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a low
gear. This way, engine drag can help your brakes and
they won’t have to do all the work. Descend slowly,
keeping your vehicle under control at all times.
I a CAUTIO, .:
0
0
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could
cause loss of control and
a serious accident.
Apply the brakes lightly when descending a
hill and use a low gear to keep vehicle speed
under control.
&: Are there some things I should not do when
A: Yes! These are important because if you ignore them
driving down a hill?
you could lose control and have a serious accident.
When driving downhill, avoid turns that take you
across the incline
of the hill. A hill that’s not too
steep to drive down may be too steep to drive across.
You could roll over if you don’t drive straight down.
Never
go downhill with the transmission in
NEUTRAL
(N), or with the clutch pedal depressed
in a manual shift. This is called “free-wheeling.”
Your brakes will have to do all the work and could
overheat and fade.
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Am I likely to stall when going downhill?
A: It’s much more likely to happen going uphill. But if
it happens going downhill, here’s what to do.
Stop your vehicle by applying the regular brakes.
Apply the parking brake.
Shift to PARK (P) (or to NEUTRAL (N) with the manual
transmission) and, while still braking, restart
the engine.
Shift back to a low gear, release the parking brake,
and drive straight down.
e If the engine won’t start, get out and get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go across
the incline of a hill. If this happens, you have to decide
whether to try to drive across the incl.ine. Here are some
things to consider:
A hill that can be driven straight up or down may
be too steep to drive across. When you go straight
up or down
a hill, the length of the wheel base (the
distance from the front wheels to the rear wheels)
reduces
the likelihood the vehicle will tumble end
over end. But when you drive across an incline, the
much more narrow track width (the distance between
the left and right wheels) may not prevent the vehicle
from tilting and rolling over. Also, driving across
an
e
e
incline puts more weight on the downhill wheels.
This could cause a downhill slide or
a rollover.
Surface conditions can be a problem
when you drive
across
a hill. Loose gravel, muddy spots, or even wet
grass can cause your tires
to slip sideways, downhill.
If the vehicle slips sideways, it can hit something
that will trip it (a rock, a rut, etc.) and roll over.
Hidden obstacles can make the steepness of
the
incline even worse. If you drive across a rock with
the uphill wheels, or if the downhill wheels drop into
a
rut or depression, your vehicle can tilt even more.
For reasons like these, you need to decide carefully
whether
to try to drive across an incline. Just because the
trail
goes across the incline doesn’t mean you have to
drive it. The last vehicle to
try it might have rolled over.
Driving across an incline that’s too steep will
make your vehicle roll over.
You could be
seriously injured or killed.
If you have any doubt
about the steepness
of the incline, don’t drive
across it. Find another route instead.
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If you drive regularly in steep country, or if you’re
planning to visit there, here are some tips
that can make
your trips safer and more enjoyable. (See “Off-Road
Driving” in the Index for information about
driving off-road.)
0 Keep your vehicle in good shape. Check all fluid
levels and also
the brakes, tires, cooling system and
transmission. These
parts can work hard on
mountain roads.
0 Know how to go down hills. The most important
thing
to know is this: let your engine do some of the
slowing down. Shift to a lower gear when you go
down a steep or long hill.
If you don’t shift down, your brakes could get
so hot that they wouldn’t work well. You would
then have poor braking or even none going
down a hill. You could crash. Shift down to let
your engine assist your brakes on a steep
downhill slope.
7-
Coasting downhill in NEUTRAL (N) or with the
ignition
off is dangerous. Your brakes will have to
do all the work of slowing down. They could get
so hot that they wouldn’t work well. You would
then have poor braking or even none going down
a hill.
You could crash. Always have your engine
running and your vehicle in gear when you
go downhill.
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Know how to go uphill. You may want to shift down
to
a lower gear. The lower gears help cool your engine
and transmission,
and you can climb the hill better.
Stay
in your own lane when driving on two-lane
roads in hills or mountains. Don’t swing wide
or cut
across the center
of the road. Drive at speeds that let
you stay in your own lane.
As you go over the top of a hill, be alert. There could be
something
in your lane, like a stalled car or an accident.
You may see highway signs on mountains that warn of
special problems. Examples are long grades, passing or
no-passing zones, a falling rocks area or winding
roads. Be alert
to these and take appropriate action.
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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.
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Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will flash for turns even if the bulbs
on the trailer
are burned out. Thus, you may think drivers behind you
are seeing your signal when they are not. It’s important
to check occasionally to be sure the trailer bulbs are
still working.
Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade. If you don’t shift
down,
you might have to use your brakes so much that
they would get hot and no longer work well.
On
a long uphill grade, shift down and reduce your
speed
to around 45 mph (70 km/h) to reduce the
possibility of engine and transmission overheating. If you have an automatic transmission, you can tow
in
AUTOMATIC OVERDRIVE (a). 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).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If
you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating.
To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in
PARK (P) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine
off.
If you do get the overheat warning, see “Engine
Overheating”
in the Index.
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Parking on Hills
You really should not park your vehicle, with a trailer
attached, on a hill.
If something goes wrong, your rig
could start to move. People can be injured, and both
your vehicle and
the trailer can be damaged.
But
if you ever have to park your rig on a hill, here's
how to do
it:
1. Apply your regular brakes, but don't shift into
PARK
(P) yet for an automatic transmission, or into
gear for a manual transmission.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your parking
brake and shift
into PARK (P) for an automatic
transmission, or
REVERSE (R) for a
manual transmission.
5. If you have a four-wheel-drive vehicle, be sure
the transfer case is
in a drive gear and not in
NEUTRAL
(N).
6. Release the regular brakes.
c
It can be dangerous to get out of your vehicle if
the shift lever
is not fully in PARK (P) with the
parking brake
firmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured.
To be sure your vehicle won't move, even
when you're on fairly level ground, use the steps
that follow.
If you have four-wheel drive and your transfer
case
is in NEUTRAL (N), your vehicle will be free
to roll, even if your shift lever
is in PARK (P). So,
be sure the transfer case is in a drive gear -- not
in
NEUTRAL (N).
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When You Are Ready to Leave After
Parkine
on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine;
Shift into a gear; and
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important
in trailer
operation are automatic transmission fluid (don’t
overfill), engine oil, axle lubricant, belt, cooling system
and brake adjustment. Each
of these is covered in this
manual, and
the Index will help you find them quickly.
If you’re trailering, it’s a good idea to review these
sections before you start your trip.
Trailer Wiring Harness
A seven-wire harness is stored under the rear end of
your vehicle, between
the frame rails. An electrical
connector will need to be installed at the trailer end of
the harness, by a qualified electrical technician. For
additional trailer wiring and towing information please
consult your
GM dealer. Securely attach the harness to
the trailer, then tape or strap
it to your vehicle’s frame
rail. Be sure you leave it loose enough
so the wiring
won’t bind or break when turning with the trailer, but
not
so loose that it drags on the ground. Store the
harness in its original position. Wrap the harness
together and tie
it neatly so it won’t be damaged. If you
tow
a trailer, your Center High-Mounted Stoplamp
(CHMSL) may not be properly visible from behind.
You
should select a trailer with a CHMSL on it or, if one is
not available, have one installed. See your
GM dealer
about how to connect your vehicle’s wiring
to a
trailer CHMSL.
Check periodically to see that all hitch nuts and bolts
are tight.
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Power Winches
If you wish to use a power winch on your vehicle, only
use it when your vehicle is stationary or anchored.
I NOTICE:
Using a power winch with the transmission in
gear may damage the transmission. When
operating a power winch, always leave the
transmission in NEUTRAL
(N).
Use the regular brakes, set the parking brake, or block
the wheels
to keep your vehicle from rolling.
Power Take-Off (PTO) (Manual Tkansmission)
NOTICE:
If you have a PTO that will exceed 35 hp installed
on your vehicle, it could damage the transfer case
or transmission. When having
a PTO installed
on
your vehicle, make sure that it will not exceed
35 hp. Before using
a PTO, refer to the manufacturer’s
or
installer’s instructions.
I NOTICE:
Using a PTO while operating in one place before
the vehicle has reached normal operating
temperature can damage the transfer case or
transmission. If you will be using the
PTO while
operating in one place, drive and warm up the
vehicle before using the
PTO.
To engage a PTO:
1. Hold the clutch pedal down.
2. Set the parking brake.
3. Shift the transmission into NEUTRAL (N).
4. Engage the PTO.
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