1998 GMC SIERRA Owners Manual

Four-wheel Drive (If Equipped)
If your vehicle has four-wheel drive, you can send your
engine’s driving power to all four wheels for
extra
traction. To get the most satisfaction out of four-wheel
drive, you must be familiar with its operation. Read the
part that follows before using four-wheel drive. You
should use
2-WHEEL HIGH (2H) for most normal
driving conditions.
I i
I NOTICE:
Driving in the 4-WHEEL HIGH (4H) or
4-WHEEL LOW (4L) positions for a long time
on dry or wet pavement could shorten the life
of
your vehicle’s drivetrain.
Front Axle Locking Feature
The front axle locks and unlocks automatically when you
shift the transfer case. Some delay for the axle to lock or
unlock is normal.
If the outside temperature is very hot, or
the vehicle has been used under hard driving conditions,
there may
be a slight delay for the axle to unlock.
Manual Transfer Case (If Equipped)
The transfer case shift lever is on the floor to the right of
the driver. Use this lever to shift into and out of
four-wheel drive.
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I ~ The front axle portion of the indicator diagram will light
up when you shift into four-wheel drive and the front
axle engages.
Some delay between shifting and the indicator’s lighting
is normal. If the front axle light does not go out
immediately after you shift out of four-wheel drive,
1 have your dealer check your system.
An indicator near the lever shows you the transfer
case settings:
2-Wheel High (2H): This setting is for driving in most
street and highway situations. Your front axle is not
engaged in two-wheel drive. 4-Wheel High
(4H): This setting engages your front
axle to help drive your vehicle. Use
4H when you need
extra traction and in most off-road situations.
Shifting the transfer case to
NEUTRAL (N) can
cause your vehicle to roll even
if the transmission
is in
PARK (P), or if you have a manual
transmission, even if you are in gear. You or
someone else could be seriously injured. Be
sure
to set the parking brake before placing the
transfer case in
NEUTRAL (N). See “Parking
Brake” in the Index.
NEUTRAL (N): Shift to this setting only when your
vehicle needs to be towed or when using a power take-off.
4-Wheel
Low (4L): This setting also engages your front
axle to give you extra power and also gives you
a higher
driveline ratio. It should be used only for off-road driving.
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You can shift from 2-WHEEL HIGH (2H) to 4-WHEEL
HIGH (4H) or from 4-WHEEL HIGH (4H) to
2-WHEEL HIGH (2H) while
the vehicle is moving.
Your front axle will engage faster
if you take your foot
off the accelerator for a few seconds after you shift. In
extremely cold weather, it may be necessary to stop or
slow the vehicle
to shift into 4-WHEEL HIGH (4H).
To
shift into or out of 4-WHEEL LOW (4L) or
NEUTRAL
(N):
1. Slow the vehicle to a roll, about 1 to 3 mph
(2
to 5 km/h) and shift an automatic transmission
into NEUTRAL
(N), or with a manual transmission,
press the clutch pedal.
2. Shift
the transfer case shift lever in one
continuous motion.
Don’t pause
in NEUTRAL (N) as you shift the
transfer case into 4-WHEEL LOW (4L), or your
gears
could clash.
Remember that driving
in 4-WHEEL HIGH (4H) or
4-WHEEL LOW (4L) may reduce
fuel economy. Also,
driving
in four-wheel drive on dry pavement could
cause your tires to wear faster and make your transfer
case harder
to shift and run noisier. When your headlamps
or parking lamps are on, rotate the
thumb wheel next
to the headlamp switch up to brighten
or down to dim your transfer case indicator light.
Electronic Transfer Case (If Equipped)
If your four-wheel-drive vehicle has the electronic
transfer case,
the transfer case switches are below and to
the left of the climate control system.
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Use these switches to shift into and out of four-wheel
drive. You can choose among three driving settings:
2HI: This setting is for driving in most street and
highway situations. Your front axle is not engaged
in
two-wheel drive.
4HI: This setting engages your front axle to help
drive your vehicle. Use 4HI when you need extra
traction, such as
on snowy or icy roads, or in most
off-road situations.
4LO: This setting also engages your front axle to give
you extra traction. You may never need 4LO. It sends
the maximum power to all
four wheels. You might
choose 4LO if you were driving off-road in sand, mud
or deep snow and climbing or descending steep hills.
Indicator lights in the switches show you which setting
you are in. The indicator lights will come on briefly when
you
turn on the ignition and the last chosen setting will
stay on. If the lights
do not come on, you should take your
vehicle in for service. An indicator light will flash while
shifting. It will remain illuminated when
the shift is
completed. If for some reason the transfer cannot make a
requested shift, it will return
to the last chosen setting.
Shifting from 2HI to 4HI
Press and release the 4HI switch. This can be done at
any speed, and the front axle will lock automatically
with some delay.
Shifting from 4HI to 2HI
Press and release the 2HI switch. This can be done at
any speed, and the front axle will unlock automatically
with some delay.
ting from 2HI or 4HI to 4LO
'li hift from 2HI or 4HI to 4L0, the vehicle must be
stopped or moving less than
3 mph (4.8 km/h) with the
transmission in
NEUTRAL (N). The preferred method
for shifting into 4LO is to have your vehicle moving
1 to
2 mph (1.6 to
3.2 kmh). Press and release the 4LO
switch. You must wait for the
4LO indicator light to stop
flashing and remain illuminated before shifting your
transmission into gear.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will flash
for 30 seconds and not complete the shift unless your
vehicle is moving slower than
3 mph (4.8 kmh) and the
transmission is
in NEUTRAL (N). After 30 seconds the
transfer case will return to 4HI.
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Shifting from 4LO to 4HI or 2HI
To shift from 4LO to 4HI or 2H1, your vehicle must be
stopped or moving less than
3 mph (4.8 km/h) with the
transmission in
NEUTRAL (N). The preferred method
for shifting out of
4LO is to have your vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Press and release the 4HI
switch. You must wait for the 4HI indicator light to stop
flashing and remain illuminated before shifting your
transmission into gear.
If the 4HI switch is pressed when your vehicle is in gear
and/or moving, the
4HI indicator light will flash for
30 seconds but will not complete the shift unless the
vehicle is moving slower than
3 mph (4.8 km/h) and the
transmission is in
NEUTRAL (N).
Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking brake
pedal with your left foot.
If the ignition is on, the brake system warning light will
come on.
To release the parking brake, hold the regular brake
pedal down. Pull
the lever, located
just above the parking
brake pedal, marked
BRAISE RELEASE.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
NOTICE:
Driving with the parking brake on can cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle. Always check to be sure
your parking brake is fully released before
you drive.
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If you are towing a trailer and are parking on any hill,
see “Towing a Trailer” in the Index. That section shows
what to do first
to keep the trailer from moving.
Shifting Into PARK (P) (Automatic
Transmission Only)
If you have a 3500 HD model, it is recommended that
the propshaft mounted parking brake be burnished
as
part of the new vehicle break-in. The parking brake
will work best after
it has been burnished following
these instructions.
Make
10 stops, using the parking brake foot pedal, from
20 mph (32 kmh) about 2 1/2 miles (4 km) apart. In
between stops, drive the vehicle at
20 mph (32 km/h).
A CAUTION:
-
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 fourwheel 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). If you’re pulling a trailer, see
“Towing a Trailer” in the Index.
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1.
2.
Hold the brake pedal down with your right foot and
set the parking brake.
Move
the shift lever into PARK (P) position like this:
r
3.
Pull the lever toward you.
4.
5.
Move the lever up as far as it will go.
If you have four-wheel drive, be sure the transfer
case is in a drive gear
-- not in NEUTRAL (N).
Turn the ignition key to LOCK.
Remove the key and take it with you. If you can
leave your vehicle with the ignition key in your
hand, your vehicle is in PARK
(P).
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Leaving Your Vehicle With the Engine
Running (Automatic Transmission
Only)
I A CATJTION:
It can be dangerous to leave your vehicle with the
engine running. Your vehicle could move
suddenly if the shift lever
is not fully in PARK (P)
with the parking brake firmly set. If you have
four-wheel drive with
a manual transfer case
shift lever 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). And, if you leave the vehicle with
the engine running, it could overheat and even
catch fire.
You or others could be injured. Don’t
leave your vehicle with the engine running unless
you have to. If you
have to leave your vehicle with the engine
running, be sure your vehicle
is in PARK (P) and the
parking brake is firmly set before you leave it. After
you
move the shift lever into PARK (P), hold the regular
brake pedal down. Then, see if you can move the shift
lever away from PARK
(P) without first pulling it
toward you. If you can, it means that
the shift lever
wasn’t
fully locked into PARK (P).
Torque Lock (Automatic Transmission)
If you are parking on a hill and you don’t shift your
transmission into PARK (P) properly, the weight of the
vehicle may put
too much force on the parking pawl in
the transmission.
You may find it difficult to pull the
shift lever out of PARK
(P). This is called “torque lock.”
To prevent torque lock, set the parking brake and then
shift
into PARK (P) properly before you leave the
driver’s seat.
To find out how, see “Shifting Into
PARK
(P)” in the Index.
When
you are ready to drive, move the shift lever out of
PARK (P)
before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some
of the
pressure from the parking pawl in the transmission,
so
you can pull the shift lever out of PARK (P).
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