2008 CHEVROLET SILVERADO transmission

REVERSE (R):Use this gear to back up.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
Shift to REVERSE (R) only after your vehicle is
stopped.
To rock your vehicle back and forth to get out of snow,
ice, or sand without damaging your transmission, seeIf
Your Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-34.
NEUTRAL (N):In this position, your engine does not
connect with the wheels. To restart when you are
already moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your vehicle is being towed.
{CAUTION:
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless
your foot is rmly on the brake pedal, your
vehicle could move very rapidly. You could
lose control and hit people or objects. Do not
shift into a drive gear while your engine is
running at high speed.Notice:Shifting out of PARK (P) or NEUTRAL (N)
with the engine running at high speed may damage
the transmission. The repairs would not be
covered by your warranty. Be sure the engine is not
running at high speed when shifting your vehicle.
DRIVE (D):This position is for normal driving.
It provides the best fuel economy for your vehicle.
If you need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next
gear and has more power.
DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road driving.
You might want to shift the transmission to a lower gear
selection if the transmission shifts too often.
Downshifting the transmission in slippery road conditions
could result in skidding. See Skidding underLoss of
Control on page 4-11.
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Your vehicle has a shift stabilization feature that adjusts
the transmission shifting to the current driving conditions
in order to reduce rapid upshifts and downshifts. This shift
stabilization feature is designed to determine, before
making an upshift, if the engine is able to maintain vehicle
speed by analyzing things such as vehicle speed, throttle
position, and vehicle load. If the shift stabilization feature
determines that a current vehicle speed cannot be
maintained, the transmission does not upshift and instead
holds the current gear. In some cases, this could appear
to be a delayed shift, however the transmission is
operating normally.
Your vehicle’s transmission uses adaptive shift controls.
Adaptive shift controls continually compares key shift
parameters to pre-programmed ideal shifts stored in the
transmissions computer. The transmission constantly
makes adjustments to improve vehicle performance
according to how the vehicle is being used, such as with
a heavy load or when temperature changes. During this
adaptive shift control process, shifting might feel different
as the transmission determines the best settings.
When temperatures are very cold, the Allison
Transmission
®and Hydra-Matic®6-Speed transmission’s
gear shifting could be delayed providing more stable
shifts until the engine warms up. Shifts could be more
noticeable with a cold transmission. This difference in
shifting is normal.MANUAL MODE (M):This position, is available on
vehicles with the Allison Transmission
®or Hydra-Matic®
6-Speed transmission. It lets drivers select the range
of gears appropriate for current driving conditions.
If your vehicle has this feature, see Range Select
Mode (Allison Transmission
®or Hydra-Matic®
6-Speed transmission) later in this section.
THIRD (3):This position is also used for normal driving.
It reduces vehicle speed more than DRIVE (D) without
using the brakes. You might choose THIRD (3)
instead of DRIVE (D) when driving on hilly, winding
roads, when towing a trailer, so there is less shifting
between gears and when going down a steep hill.
SECOND (2):This position reduces vehicle speed even
more than THIRD (3) without using your brakes. You can
use SECOND (2) on hills. It can help control your speed
as you go down steep mountain roads, but then you
would also want to use the brakes off and on.
If you manually select SECOND (2) in an automatic
transmission, the transmission will start in second gear.
You can use this feature for reducing the speed of the
rear wheels when you are trying to start your vehicle
from a stop on slippery road surfaces.
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FIRST (1):For the Hydra-Matic®4-Speed transmission
this position reduces vehicle speed even more than
SECOND (2) without using the brakes. You can use it on
very steep hills, or in deep snow or mud. If the shift lever
is put in FIRST (1) while the vehicle is moving forward,
the transmission does not shift into rst gear until the
vehicle is going slowly enough.
For an Allison Transmission
®or Hydra-Matic®6-Speed
transmission, this position reduces vehicle speed
without using your brakes. You can use it for
major/severe downgrades and off-road driving where
the vehicle would otherwise accelerate due to steepness
of grade. When you shift to FIRST (1) it provides the
lowest gear appropriate to your current road speed and
continues to downshift as the vehicle slows, eventually
downshifting to FIRST (1) gear.
Notice:Spinning the tires or holding the vehicle
in one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by your warranty. If you are stuck,
do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
Range Selection Mode (Allison®or
Hydra-Matic®6-Speed Transmission)
Your vehicle may have a Range Selection Mode.
The Range Selection Mode helps control the vehicle’s
transmission and vehicle speed while driving down hill or
towing a trailer by letting you select a desired range of
gears.
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To use this feature, do the following:
1. Move the shift lever to the MANUAL MODE (M).
2. Press the plus/minus buttons, located on the
steering column shift lever, to select the desired
range of gears for your current driving conditions.
When MANUAL MODE (M) is selected a number
displays next to the M, indicating the current gear.
This number is the highest gear that can be used.
However, your vehicle can automatically shift to lower
gears as it adjusts to driving conditions. This means
that all gears below that number are available. When
FIFTH (5) is selected, FIRST (1) through FIFTH (5)
gears are automatically shifted by the vehicle, but
SIXTH (6) cannot be used until the plus/minus button
located on the steering column lever is used to change
to the gear.
Grade Braking is not available when the Range
Selection Mode is active. SeeTow/Haul Mode on
page 2-34While using the Range Selection mode feature, cruise
control and the Tow/Haul mode can be used.
Notice:Spinning the tires or holding the vehicle
in one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by your warranty. If you are stuck,
do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
Low Traction Mode
If your vehicle has the Allison Transmission®,orthe
Hydra-Matic®6-Speed Automatic Transmission, it has a
Low Traction Mode that assist in vehicle acceleration
when road conditions are slippery, such as with ice or
snow. While the vehicle is at a stop, select the second
gear range using the Range Selection system. This will
limit torque to the wheels after it detects wheel slip,
preventing the tires from spinning.
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Tow/Haul ModeIf your vehicle has an automatic transmission, it
has a tow/haul mode. If your vehicle has an Allison
or Hydra-Matic
®6-speed automatic transmission see
“Tow/Haul Mode (Allison or Hydra-Matic®6-Speed
Automatic Transmission®) following. The tow/haul
mode adjusts the transmission shift pattern to reduce
shift cycling, providing increased performance, vehicle
control, and transmission cooling when towing or hauling
heavy loads.
The selector button is located on the end of the shift
lever. Turn the tow/haul on and off by pressing the
button. When the tow/haul is on, a light on the
instrument panel cluster will come on.
SeeTow/Haul Mode Light on page 3-54for more
information.
Also see Tow Haul Mode underTowing a Trailer on
page 4-55for more information.
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Tow/Haul Mode (Allison Transmission®
or Hydra-Matic®6-Speed Automatic
Transmission)
If your vehicle has an Allison or Hydra-Matic®6-speed
automatic transmission®, it has a tow/haul mode.
The tow/haul mode adjusts the transmission shift pattern
to reduce shift cycling, providing increased performance,
vehicle control, and transmission cooling when towing
or hauling heavy loads.
Turn the tow/haul mode on and off by pressing the
button, located on the end of the shift lever. When the
tow/haul is on, a light on the instrument panel cluster will
come on.
SeeTow/Haul Mode Light on page 3-54for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-55for more information.
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Grade Braking (Allison Transmission®
or Hydra-Matic®6-Speed Automatic
Transmission)
The Grade Braking shift modes can be activated by
pressing the button on the end of the shift control lever.
While in Range Selection Mode, Grade Braking is
deactivated allowing the driver to select a desired
range of gears.
Grade Braking is only active while the Tow/Haul Mode is
selected and you are not in the Range Selection Mode.
See “Tow/Haul Mode listed previously andAutomatic
Transmission Operation on page 2-28for more
information on the Range Selection Mode. Grade Braking
assists in maintaining desired vehicle speeds when
driving on downhill grades by automatically implementing
a shift schedule that utilizes the engine and transmission
to slow the vehicle. This reduces wear on the braking
system and increases control of the vehicle. Grade
Braking monitors vehicle speed, acceleration, engine
torque and brake pedal usage. Using this information,
it detects when the truck is on a downhill grade and the
driver desires to slow the vehicle by pressing the brake.
See the diesel supplement for information on Cruise
Grade Braking.
Also seeTowing a Trailer on page 4-55for more
information.
Four-Wheel Drive
If your vehicle has Four-Wheel Drive, you can send the
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. See the
appropriate text for the transfer case in your vehicle.
Notice:Driving on clean, dry pavement in
Four-Wheel-Drive High or Four-Wheel-Drive Low for
an extended period of time may cause premature
wear on your vehicle’s powertrain. Do not drive on
clean, dry pavement in Four-Wheel-Drive High or
Four-Wheel-Drive Low for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience vibration in the steering
system.
Front Axle
The front axle engages and disengages automatically
when you shift the transfer case. Some delay for
the axle to engage or disengage is normal.
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4n(Four-Wheel-Drive Low):This setting also
engages the front axle and delivers extra torque.
You may never need Four-Wheel-Drive Low. It sends
maximum power to all four wheels. You might choose
Four-Wheel-Drive Low if you are driving off-road in deep
sand, deep mud, deep snow, and while climbing or
descending steep hills. When operating in Four-Wheel
Low, the gear ratio provides additional torque when
compared to Four-Wheel-Drive High. The transmission
gear shift feel is exaggerated.
A parking brake symbol
is located next to the N
(NEUTRAL) symbol as a
reminder to set the parking
brake before shifting the
transfer case in 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 2-50.
N (NEUTRAL):Shift to this setting only when your
vehicle needs to be towed. SeeRecreational Vehicle
Towing on page 4-50orTowing Your Vehicle on
page 4-50.
2
m(Two-Wheel-Drive High):This setting is used
for driving in most street and highway situations.
The front axle is not engaged in two-wheel drive.
This setting also provides the best fuel economy.
4
m(Four-Wheel-Drive High):Use this setting when
you need extra traction, such as on snowy or icy roads or
in most off-road situations. This setting also engages the
front axle to help drive your vehicle. This is the best
setting to use when plowing snow.
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