2007 GMC SIERRA CLASSIC clutch

Shifting from Four-Wheel Drive Low to
Four-Wheel Drive High or Two-Wheel
Drive High
To shift from Four-Wheel Drive Low to Four-Wheel
Drive High or Two-Wheel Drive High, your
vehicle must be stopped or moving less than
3 mph (5 km/h) with the transmission in
NEUTRAL (N) for an automatic transmission or
the clutch pedal pressed for a manual
transmission. The preferred method for shifting out
of Four-Wheel Drive Low is to have your vehicle
moving 3 mph (5 km/h).
Press and release the Two-Wheel Drive High or
Four-Wheel Drive High switch. You must wait
for the Two-Wheel Drive High or Four-Wheel Drive
High indicator light to stop ashing and stay on
before shifting the transmission into gear or
releasing the clutch pedal.
If the Four-Wheel Drive High switch is pressed
when your vehicle is in gear, the Four-Wheel Drive
High indicator light will ash for 30 seconds but
the vehicle will not complete the shift unless
it is moving slower than 3 mph (5 km/h) and the
transmission is in NEUTRAL (N).
Shifting into NEUTRAL
{CAUTION:
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or
someone else could be seriously injured.
Be sure to set the parking brake before
placing the transfer case in NEUTRAL.
SeeParking Brake on page 169.
To shift the transfer case to NEUTRAL, rst make
sure the vehicle is parked so that it will not roll:
1. Set the parking brake and apply the regular
brake pedal.
2. Start the vehicle or turn the ignition to RUN.
3. Press the foot brake pedal and put the
transmission in NEUTRAL (N).
4. Shift the transfer case to Two-Wheel
Drive High.
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5. Simultaneously press and hold the Two-Wheel
Drive High and Four-Wheel Drive Low buttons
for 10 seconds. The red NEUTRAL light will
come on when the transfer case shift to
NEUTRAL is complete.
6. Start the engine if it is not already running.
7. Press and hold the foot brake pedal and
Shift the transmission to REVERSE (R)
for one second, then shift the transmission for
one second to DRIVE (D) for an automatic
transmission, or FIRST (1) for vehicles
that have a manual transmission. Then let out
the clutch. This is to ensure the transfer
case is in NEUTRAL. If not, repeat this
procedure starting at Step 3.
8. Turn the engine off, by turning the key to
ACCESSORY.
9. Place the transmission shift lever in PARK (P)
for an automatic transmission, or FIRST (1)
for vehicles that have a manual transmission.
10. Release the parking brake prior to moving the
vehicle.
11. Turn the ignition to LOCK.Shifting Out of NEUTRAL
To shift out of NEUTRAL:
1. Set the parking brake and press and hold the
regular brake pedal.
2. Shift the transmission to NEUTRAL (N) for an
automatic transmission, or press the clutch
pedal for vehicles that have a manual
transmission. Then turn the ignition to RUN
with the engine off.
3. Press the button for the desired transfer case
shift position (Two-Wheel Drive High,
Four-Wheel Drive High, or Four-Wheel
Drive Low).
4. After the transfer case has shifted out of
NEUTRAL the red light will go out.
5. Release the parking brake prior to moving the
vehicle.
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TRANS (Transmission) HOT IDLE
ENGINE
Notice:If you drive your vehicle while the
transmission uid is overheating and the
transmission temperature warning is displayed
on the instrument panel cluster and/or DIC,
you can damage the transmission. This could
lead to costly repairs that would not be
covered by your warranty. Do not drive your
vehicle with overheated transmission uid
or while the transmission temperature warning
is displayed.
If the transmission uid in the vehicle gets hot, this
message will appear on the DIC along with a
continuous chime. Driving with the transmission
uid temperature high can cause damage to
the vehicle. Stop the vehicle and let it idle to allow
the transmission to cool. This message will
clear and the chime will stop when the uid
temperature reaches a safe level. See
Transmission Temperature Gage on page 257.
TRANS (Transmission) IN WARM UP
(Allison Transmission®Only)
When temperatures are very cold, the transmission
will prevent certain operations such as shifts to
some ranges and engaging the torque converter
clutch to protect against damage. When active, the
DIC will display the message TRANS IN
WARM UP.
TURN SIGNAL ON
If a turn signal is left on for 3/4 of a mile (1.2 km),
this message will appear on the display and
you will hear a chime. Move the turn
signal/multifunction lever to the off position.
Pressing any of the four DIC buttons will
acknowledge the message and clear it from the
DIC display. If your vehicle does not have the
four DIC buttons, pressing the trip odometer reset
stem will acknowledge the message and clear
it from the DIC display.
281

Q:What should I do if my vehicle stalls,
or is about to stall, and I cannot make it
up the hill?
A:If this happens, there are some things you
should do, and there are some things you
must not do. First, here is what youshoulddo:
Push the brake pedal to stop the vehicle
and keep it from rolling backwards. Also, apply
the parking brake.
If the engine is still running, shift the
transmission to REVERSE (R), release the
parking brake, and slowly back down the
hill in REVERSE (R).
If the engine has stopped running, you will
need to restart it. With the brake pedal
pressed and the parking brake still applied,
shift the transmission to PARK (P), or shift to
NEUTRAL if your vehicle has a manual
transmission, and restart the engine. Then,
shift to REVERSE (R), release the parking
brake, and slowly back down the hill as
straight as possible in REVERSE (R).
As you are backing down the hill, put your left
hand on the steering wheel at the 12 o’clock
position. This way, you will be able to tell if the
wheels are straight and maneuver as you back
down. It is best that you back down the hill with
the wheels straight rather than in the left or right
direction. Turning the wheel too far to the left or
right will increase the possibility of a rollover.
Here are some things youmust notdo if you stall,
or are about to stall, when going up a hill.
Never attempt to prevent a stall by shifting into
NEUTRAL (N), or pressing the clutch if your
vehicle has a manual transmission, to rev-up
the engine and regain forward momentum. This
will not work. Your vehicle will roll backwards
very quickly and you could go out of control.
Instead, apply the regular brake to stop the
vehicle. Then apply the parking brake. Shift to
REVERSE (R), release the parking brake, and
slowly back straight down.
Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep
enough to stall your vehicle, it is steep enough
to cause you to roll over if you turn around.
If you cannot make it up the hill, you must back
straight down the hill.
383

Q:Are there some things I should not do
when driving down a hill?
A:Yes! These are important because if you
ignore them 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
is not too steep to drive down may be
too steep to drive across. You could roll
over if you do not drive straight down.
Never go downhill with the transmission in
NEUTRAL (N), or with the clutch pedal
pressed down with a manual transmission.
This is called “free-wheeling.” The brakes will
have to do all the work and could overheat
and fade.
Q:Am I likely to stall when going downhill?
A:It is much more likely to happen going
uphill. But if it happens going downhill,
here is what to do.
1. Stop your vehicle by applying the regular
brakes. Apply the parking brake.
2. Shift to PARK (P), or to NEUTRAL with the
manual transmission, and, while still braking,
restart the engine.
3. Shift back to a low gear, release the parking
brake, and drive straight down.
4. If the engine will not start, get out and get help.
386

Power Take-Off (PTO)
Before using a Power Take-Off (PTO), if equipped,
refer to the manufacturer’s or installer’s instructions.
To engage a PTO on a vehicle with a manual
transmission do the following:
1. Hold the clutch pedal down.
2. Set the parking brake.
3. Shift the transmission into NEUTRAL.
4. Engage the PTO. Refer to the manufacturer’s
or installer’s for instructions on electrically
engaged PTOs.
5. For mobile operations, shift the transmission
into the gear you want, apply the regular
brakes and release the parking brake.
For stationary operations, leave the parking
brake applied.
6. Release the clutch and regular brakes as you
normally would. When the clutch is released,
the PTO will start.
7. Turn the PTO rotary switch to ON.To engage a PTO on a vehicle with an automatic
transmission do the following:
1. For stationary use shift the transmission into
PARK (P).
2. Turn the PTO rotary switch ON.
3. If the engine speed is below the PTO engage
speed limit, the PTO will start. The blinking
LED on the PTO control switch indicates PTO
engage is requested. When PTO engages the
LED will switch from blinking to a steady light.
To use PTO speed control in Preset Mode (Factory
Setting) do the following:
1. Engage the PTO.
2. Select PARK (P) or NEUTRAL (N) range.
Apply the parking brake if NEUTRAL (N) is
selected. Torque Converter Clutch (TCC)
is not available in NEUTRAL (N) and is
available only in PARK (P) when engine speed
is above 1,100 rpm.
3. Make sure your foot is off the brake pedal
(and off the clutch on vehicles equipped
with a manual transmission).
4. Select the desired engine speed for PTO
operation. Read the following preset mode
information regarding operation.
461

Preset Mode:PTO speed control mode is used
for stationary applications. (PTO will remain
engaged while mobile in the preset mode, however
PTO set and resume speed controls will be
inoperative.) This mode provides a default standby
speed of 800 or 850 rpm (depending on the
engine/transmission combination) and two default
PTO control speeds which follow:
1. PTO Set Speed of 1,250 rpm, or
2. PTO Resume Speed of 1,700 rpm.
Please note that the standby speed (800/850 rpm)
is not to be used as a PTO control speed.
Vehicles not equipped with cruise control will not
have the resume speed capability.
To use PTO speed control in variable mode (while
mobile) do the following:
1. Engage the PTO.
2. Vehicle speed must be greater than 5 mph.
3. Make sure your foot is off the brake pedal
(and off the clutch for vehicles equipped
with a manual transmission).
4. Select the desired engine speed by using the
foot pedal, and select SET on the PTO switch
or the cruise control.To use PTO speed control in variable mode (while
stationary) do the following:
1. Engage the PTO.
2. Vehicle speed must be less than 5 mph.
3. Make sure your foot is off the brake pedal
(and off the clutch for vehicles equipped
with a manual transmission).
4. Select the desired engine speed by using the
foot pedal, and select SET on the PTO switch
or the cruise control.
Variable Mode:PTO speed control mode can be
used for both stationary and mobile applications.
This mode allows PTO to be controlled in a fashion
similar to how cruise control sets vehicle speed.
The operator can set to an rpm (between 800 and
2,200) with the cruise control feature or with the
SET position on the PTO switch. The operator
is then able to increase rpm in increments of 100,
or “tap up” with the resume position on the
cruise control. The operator can also decrease
rpm in increments of 100 with the SET switch on
the PTO or the cruise control.
Vehicles not equipped with cruise control will not
have the “tap up” capability.
462

Service........................................................ 468
Accessories and Modications................... 468
California Proposition 65 Warning.............. 469
Doing Your Own Service Work.................. 469
Adding Equipment to the Outside of
Your Vehicle.......................................... 470
Fuel............................................................. 470
Gasoline Octane........................................ 470
Gasoline Specications.............................. 471
California Fuel........................................... 471
Additives................................................... 472
Fuel E85 (85% Ethanol)............................ 473
Fuels in Foreign Countries........................ 474
Filling the Tank......................................... 474
Filling a Portable Fuel Container............... 477
Checking Things Under the Hood.............. 478
Hood Release........................................... 479
Engine Compartment Overview.................. 480
Engine Oil (Gasoline Engine).................... 486
Engine Oil Life System
(Gasoline Engine).................................. 489
Engine Air Cleaner/Filter
(Gasoline Engines)................................. 491Automatic Transmission Fluid
(Allison Transmission®) .......................... 494
Automatic Transmission Fluid
(Except Allison Transmission
®) ............... 497
Manual Transmission Fluid........................ 500
Hydraulic Clutch........................................ 501
Engine Coolant.......................................... 502
Coolant Surge Tank Pressure Cap............ 505
Engine Overheating................................... 505
Overheated Engine Protection
Operating Mode (V8 Engines Only)........ 508
Cooling System......................................... 508
Engine Fan Noise..................................... 514
Power Steering Fluid ................................. 515
Windshield Washer Fluid........................... 516
Brakes...................................................... 517
Battery...................................................... 520
Jump Starting............................................ 521
Rear Axle.................................................... 527
Four-Wheel Drive........................................ 528
Front Axle................................................... 529
Section 5 Service and Appearance Care
465