The 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.
The 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.M (Manual Mode):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 the
vehicle has this feature, see Range Select Mode
(Allison Transmission
®or Hydra-Matic®6-Speed
transmission) later in this section.
3 (Third):This position is also used for normal driving.
It reduces vehicle speed more than D (Drive) without
using the brakes. You might choose 3 (Third) instead of
D (Drive) when driving on hilly, winding roads, when
towing a trailer, so there is less shifting between gears
and when going down a steep hill.
2 (Second):This position reduces vehicle speed even
more than 3 (Third) without using the brakes. You
can use 2 (Second) on hills. It can help control vehicle
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 2 (Second) 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 the vehicle
from a stop on slippery road surfaces.
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Shifting Out of Four-Wheel-Drive Low
To shift from Four-Wheel-Drive Low to Four-Wheel-Drive
High, or Two-Wheel-Drive High, the vehicle must be
stopped or moving less than 3 mph (5 km/h) with
the transmission in N (Neutral) and the ignition in
ON/RUN. The preferred method for shifting out of
Four-Wheel-Drive Low is to have the vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Turn the knob to the
Four-Wheel-Drive High, or Two-Wheel-Drive High
position. You must wait for the Four-Wheel-Drive High,
or Two-Wheel-Drive High indicator light to stop
ashing and remain on before shifting the transmission
into gear.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To
help avoid damaging the vehicle, always wait for the
mode indicator lights to stop ashing before
shifting the transmission into gear.
It is typical for the vehicle to exhibit signi cant
engagement noise and bump when shifting between
Four-Wheel-Drive Low and Four-Wheel-Drive High
ranges or from transfer case N (Neutral) with the engine
running.If the knob is turned to the Four-Wheel-Drive High, or
Two-Wheel-Drive High switch position when the vehicle
is in gear and/or moving, the Four-Wheel-Drive High,
or Two-Wheel-Drive High indicator light will ash
for 30 seconds but will not complete the shift unless
your vehicle is moving less than 3 mph (5 km/h) and the
transmission is in N (Neutral).
Shifting into Neutral
To shift the transfer case to N (Neutral) do the following:
1. Make sure the vehicle is parked so that it will not roll.
2. Set the parking brake and press and hold the
regular brake pedal. SeeParking Brake on
page 2-50for more information.
3. Start the vehicle or turn the ignition to ON/RUN.
4. Shift the transmission to N (Neutral).
5. Shift the transfer case to Two-Wheel-Drive High.
6. Turn the transfer case dial clockwise to N (Neutral)
until it stops and hold it there until the Neutral light
starts blinking. This will take at least 10 seconds.
Then slowly release the dial to the four low position.
The N (Neutral) light will come on when the
transfer case shift to N (Neutral) is complete.
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7. If the engine is running, verify that the transfer case
is in N (Neutral) by shifting the transmission to
R (Reverse) for one second, then shift the
transmission to D (Drive) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in P (Park).
10. Release the parking brake prior to moving the
vehicle.
11. Turn the ignition to LOCK/OFF.
Shifting Out of Neutral
To shift the transfer case out of N (Neutral) do the
following:
1. Set the parking brake and apply the regular brake
pedal.
2. Turn the ignition to ON/RUN with the engine off,
and shift the transmission to N (Neutral).
3. Turn the transfer case dial to Two-Wheel-Drive High.
After the transfer case has shifted out of N (Neutral),
the N (Neutral) light will go out.
4. Release the parking brake prior to moving the
vehicle.Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To
help avoid damaging the vehicle, always wait for the
mode indicator lights to stop ashing before
shifting the transmission into gear.
5. Start the engine and shift the transmission to the
desired position.
Excessively shifting the transfer case into or out of the
different modes may cause the transfer case to
enter the shift protection mode. This will protect the
transfer case from possible damage and will only allow
the transfer case to respond to one shift per
10 seconds. The transfer case may stay in this mode for
up to three minutes.
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Shifting into Neutral
To shift the transfer case to N (Neutral) do the following:
1. Make sure the vehicle is parked so that it will
not roll.
2. Set the parking brake and apply the regular brake
pedal. SeeParking Brake on page 2-50for more
information.
3. Start the vehicle or turn the ignition to ON/RUN.
4. Put the transmission in N (Neutral).
5. Shift the transfer case to Two-Wheel Drive High.
6. Turn the transfer case dial clockwise to N (Neutral)
until it stops and hold it there until the N (Neutral)
light starts blinking. This will take at least
10 seconds. Then slowly release the dial to the four
low position. The N (Neutral) light will come on
when the transfer case shift to N (Neutral) is
complete.
7. If the engine is running, make sure that the transfer
case is in N (Neutral) by shifting the transmission to
R (Reverse) for one second, then shift the
transmission to D (Drive) for one second.
8. Turn the ignition to ACC/ACCESSORY, which will
turn the engine off.
9. Place the transmission shift lever in P (Park).10. Release the parking brake prior to moving the
vehicle.
11. Turn the ignition to LOCK/OFF.
Shifting Out of Neutral
To shift out of N (Neutral) do the following:
1. Set the parking brake and apply the regular brake
pedal.
2. Turn the ignition to ON/RUN with the engine off,
and shift the transmission to N (Neutral).
3. Turn the transfer case dial to Two-Wheel-Drive
High, Four-Wheel-Drive High, AUTO.
After the transfer case has shifted out of N (Neutral),
the N (Neutral) light will go out.
4. Release the parking brake prior to moving the
vehicle.
Notice:Shifting the transmission into gear before
the requested mode indicator light has stopped
ashing could damage the transfer case. To
help avoid damaging the vehicle, always wait for the
mode indicator lights to stop ashing before
shifting the transmission into gear.
5. Start the engine and shift the transmission to the
desired position.
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