clutch CHEVROLET C/K 2003 Owners Manual

2-16 Engine Starter Over-Crank Protection
(If Equipped)
Your vehicle may have an engine starter over-crank
protection system. If the starter motor overheats and
shuts off due to over
-cranking, the motor must cool
down before it will reset and allow starter operation.
It can take up to six minutes before the starter will
work again.
Starting Your Gasoline Engine
Engines start differently. The 8th digit of your Vehicle
Identification Number (VIN) shows the code letter for
your engine. See ªVehicle Identification Numberº in
the Index. Follow the proper steps to start the engine.
To start a diesel engine, see ªStarting Your Diesel
Engineº in the Index.
Automatic Transmission
Set the parking brake and move your shift lever to
NEUTRAL (N) or PARK (P) if so equipped. Your
engine won't start in any other position
-- that's a
safety feature.
Manual Transmission
Set the parking brake, shift to neutral and hold the clutch
pedal to the floor while starting the engine.
Starter Motor Operation

The starter motor will disengage if you release
the key or the engine reaches a predetermined
engine speed.

To prevent overheating, the starter motor will
disengage after continuously operating for
15 seconds. You must release the key from the
start position to re
-engage the starter.

The starter motor will not engage if the engine is
already running.

The starter motor will disengage if, after
two seconds, the starter pinion gear does not
engage the flywheel or there is no engine rpm
signal from the engine speed sensor.

2-18 Gasoline Engine Warm-Up
When you've started your engine, let it run for 20 or
30 seconds to warm up before you put a load on
the engine.
Drive at moderate speeds for the first few miles,
especially in cold weather. Running a cold engine at
high speed can damage it. See ªEngine High Idle
Systemº in the Index if your vehicle has this feature.
Restarting the Gasoline Engine While
Moving (Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, you'll first have to shift the automatic
transmission to NEUTRAL (N). This safety feature
prevents starting the engine when the transmission is
in a drive gear.
Stopping the Gasoline Engine
Let your engine idle for a few seconds before turning it
off after you have finished driving your vehicle.
If you shift to NEUTRAL (N) or PARK (P), set the
parking brake.
If your vehicle has a two
-speed axle, put the range
selector in LOW. To be sure the axle has shifted into
LOW, engage the clutch and transmission; the vehicle
may move slightly when you do this.
While your engine is idling before you turn it off, you
can make a list of any operational or handling concerns
to give to responsible maintenance personnel so they can
handle them right away.
Moisture will condense in a fuel tank that is almost
empty if the engine has not run for a while, even just
overnight under some conditions. So, it's always best to
refuel your vehicle at the end of each run.

2-21 Engine Alarm and Automatic Shutdown
(If Equipped)
Your check gages light will come on if the system senses
high engine temperature or low engine oil pressure. If high
engine temperature or low engine oil pressure is detected,
you will also hear a tone alarm at two beats per second.
The alarm and the light will remain on until the condition
is fixed. If the engine temperature or oil pressure condition
worsens, the tone alarm will go to five beats per second.
If the system senses low engine coolant, the five beat
per second alarm and the low coolant warning light will
come on.
The five beats per second tone alarm means that your
engine will shut down in approximately 25
-30 seconds.
There is also an engine shutdown light to indicate that
the engine will shut down. See ªAutomatic Engine
Shutdown Lightº later in this section.
Pull off the road and shut off the engine. Don't start it
until the reason for the problem is known, and the
problem is fixed. If the engine shuts down when you are
still in traffic, you can restart the engine and get another
25
-30 seconds of operation. Do this only if you have to,
since there is a problem that can harm the engine if it
isn't fixed. Engine automatic shutdown, for gasoline
engines, requires activation by your dealer.
High Idle System (Caterpillar
Diesel
and Gasoline Engines)
Your vehicle has both automatic and manual high idle
capabilities.
Automatic High Idle System (Diesel Engines)
(If Equipped)
The automatic high idle feature will engage whenever
you start your vehicle and the engine is below the preset
operating temperature. This will help decrease engine
warm
-up time.
Idle speed will then return to normal under any of the
following conditions:

The engine reaches the preset operating temperature
or has been operating for at least ten minutes.

The brake pedal is pressed.

The manual transmission clutch pedal is pressed or,
the automatic transmission (if equipped) is shifted
from NEUTRAL (N) or PARK (P).

The vehicle speed exceeds approximately
5 mph (8 km/h).

The throttle is pressed.

2-23 Exhaust Restrictor (Diesel Engines)
(If Equipped)
If your vehicle is equipped with this feature, there is an
exhaust restrictor valve located in the exhaust stream.
The valve closes to provide back pressure to the engine
for the purpose of warming the engine quickly.
The exhaust restrictor operates:

while the engine is running.

while the vehicle is not moving.

while the accelerator, brake and clutch pedals are
not pressed.

while idling or driving in cold temperatures.

when the shift lever is in NEUTRAL (N)
or PARK (P).On vehicles equipped with a diesel engine exhaust
brake, the exhaust brake switch must be on. The
indicator in the exhaust brake switch will be lit when the
exhaust restrictor is active. The exhaust brake indicator
light in the center of the instrument panel will also be lit
whenever the exhaust restrictor is active.
When the engine coolant temperature is below 149F
(65C) and the outside temperature is below 50F
(10C), the exhaust restrictor will come on within
45 seconds of starting the engine. After running the
engine for an additional 45 seconds, the engine idle
will increase.
The exhaust restrictor will shut off and engine idle will
return to normal once the engine is warmed up, or the
transmission is shifted into range.

2-24
Starting Your DURAMAX

Diesel Engine
Your diesel engine starts differently than a
gasoline engine.
Automatic Transmission
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine won't start in any other position
-- that's
a safety feature. To restart when you're already moving,
use NEUTRAL (N) only.
NOTICE:
Don't try to shift to PARK (P) if your vehicle is
moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.
Manual Transmission
Move your shift lever to neutral and hold the clutch
pedal to the floor while starting the engine. Your vehicle
won't start if the clutch pedal is not all the way
down
-- that's a safety feature.
Starting Your Engine
1. Turn your ignition key to RUN.
Observe the wait to start light. See ªWait To Start
Lightº in the Index. (This light may not come on
if the engine is hot.)
2. As soon as the wait to start light goes off,
IMMEDIATELY turn the ignition key to START.
When the engine starts, let go of the key.
NOTICE:
Holding your key in START for longer than
15 seconds at a time will cause your battery to be
drained much sooner. And the excessive heat can
damage your starter motor.

2-31
The accelerator and clutch pedals must be released in
order for the exhaust brake to engage. The exhaust brake
will not function when the cruise control feature is
active, and will automatically shut off when the
anti
-lock brake system is active.
CAUTION:
Be careful when using the exhaust brake or you
could lock the wheels and lose control of the
vehicle. Operators not familiar with an exhaust
brake should not use this brake on slippery
surfaces before learning to use it on dry surfaces.
If the vehicle's wheels begin to lock when using
the exhaust brake on slippery surfaces, switch the
exhaust brake off immediately. The exhaust
brake will turn off if the anti
-lock brake system
is activated.
Tw o-Speed Rear Axle Electric Shift
Control (If Equipped)
If your vehicle is equipped with this feature, you'll find
a label on the headliner above the windshield or in
another place near the driver that shows how to use it.
Be sure to follow the directions carefully.
Use the following directions based on the type of shift
control you have.
Manual Transmission
The rear axle shift control
switch for a manual
transmission is located
on the shift lever.
When the switch is up, the rear axle is in the high range.
Push the switch down to change to low range.

2-32
The two-speed axle should be in low when you park the
vehicle. You'll need to engage the transmission, even
move the vehicle a little, to be sure the axle is in the low
range. Then apply the parking brake, shift into
NEUTRAL and shut off the engine.
Also, always start the vehicle in motion with the
two
-speed axle in the low range. To shift up from low to
high, do the following:
1. Move the switch up for the high range,
2. disengage the clutch, and
3. after a brief pause, engage the clutch and then press
down on the accelerator.
To shift down from high to low, do the following:
1. Move the switch down to low,
2. release the accelerator and then quickly apply
it again.
Automatic Transmission
The rear axle shift control
switch for an automatic
transmission is located in
the instrument panel
switchbank.
Press the bottom of the switch to get to the low range.
The switch indicator light will come on when the
vehicle is in low range. Press the top of the switch to
return to the high range.
The two
-speed axle should be in low range when you
park the vehicle. Apply the parking brake, shift to
PARK (P) or NEUTRAL (N) and shut off the engine.
To operate off
-road or under a heavy load, shift into low
range when the vehicle is standing still and then operate
the transmission normally.

2-36 Overdrive Defeat (If Equipped)
If your vehicle has this feature, you can select not to
shift up to fifth gear. This is useful when towing or
under a heavy load.
The overdrive defeat switch
is located in the instrument
panel to the right of the
steering column.
Press the switch to limit the transmission to fourth gear.
This will allow for better fuel economy and fewer
downshifts while pulling a tractor or trailer or under a
heavy load. The indicator light in the switch will come
on whenever overdrive defeat is active.
Manual Transmission Operation
Using the Clutch
When you're starting to move the vehicle, it's important
to begin with the engine speed at idle. Then start to
engage the clutch and listen for an engine speed drop
of about 100 rpm. At this point, the clutch is engaging,
so you should increase the engine speed and fully
engage the clutch. It's important not to increase the
engine speed sooner or before the clutch begins it's
engagement. If you do, you can cause damage to
your vehicle.
Double-Clutching
You must use the double-clutching method when you
shift an unsynchronized gear set. Disengage the clutch,
shift to neutral and engage the clutch. When upshifting,
slow the engine until the engine rpm and road speed
match. When downshifting, accelerate the engine until
the engine rpm and road speed match. Then quickly
disengage the clutch and move the shift lever to the next
gear position and engage the clutch.

2-37 Eaton Fuller Five and Six-Speed
Transmissions and TTC Spicer
Seven-Speed Transmissions
These transmissions have gears that automatically
synchronize when you shift up or down (except
FIRST (1) gear on the five
-speed and seven-speed
transmission which is unsynchronized). Choose the gear
that will maintain the road speed you want while
keeping the engine above two
-thirds of the governed
speed. When the engine speed drops below two
-thirds of
the governed speed, shift into the next lower gear before
your engine begins to lug. When you shift down, be sure
to double
-clutch if required.
ZF Six-Speed Transmission
Here's how to operate
your transmission.
This six
-speed pattern is unique to GM manual
transmissions. The transmission always repositions
the shift lever to neutral, which is located between
FOURTH (4) and FIFTH (5) gear.
To prevent unintentional gear selections, additional
force is required to move the shift lever into
REVERSE (R) or FIRST (1). Use FIRST (1) when
trailer towing, driving with payload in the pickup box or
launching on a grade. Otherwise, start in SECOND (2)
gear. Only shift into FIRST (1) when the vehicle has
stopped moving.

2-38
During the first 500 miles (805 km) of vehicle use, start
the vehicle moving in FIRST (1) gear. This allows the
clutch components to wear
-in properly.
FIRST (1): With the vehicle at a stop, release the brake,
press the clutch pedal and shift into FIRST (1). Then,
slowly let up on the clutch pedal as you press the
accelerator pedal. Only downshift into FIRST (1) when
the vehicle has come to a complete stop. If the shift
lever will not go into FIRST (1), put the lever in neutral
and let up on the clutch pedal to fully engage the clutch.
Press the clutch pedal again. Then, shift into FIRST (1).
SECOND (2): With the vehicle at a stop, release the
brake, press the clutch pedal and shift into
SECOND (2). Then, slowly let up on the clutch pedal as
you press the accelerator pedal. With the vehicle
moving, press the clutch pedal and upshift into
SECOND (2) from FIRST (1) while applying light
pressure to the right on the shifter. Then, slowly let up
on the clutch pedal as you press the accelerator pedal.
If you come to a complete stop and the shift lever will
not go into SECOND (2), put the lever in neutral and let
up on the clutch pedal to fully engage the clutch. Press
the clutch pedal again. Then, shift into SECOND (2).THIRD (3): Press the clutch pedal and upshift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
FOURTH (4), FIFTH (5) and SIXTH (6): Upshift
into the higher forward gears the same way as you do
THIRD (3). Slowly let up on the clutch pedal as you
press the accelerator pedal.
NEUTRAL: Use this position when you start or idle
your engine.
REVERSE (R): To back up, press the clutch pedal.
Wait for the vehicle to stop moving and then, shift to
REVERSE (R). Let up on the clutch slowly while
pressing the accelerator pedal. Also, use REVERSE (R),
along with the parking brake, when turning off your
engine and parking your vehicle.