2008 DODGE RAM 2500 DIESEL engine

Downshifting
Moving from a high gear down to a lower gear is
recommended to preserve brakes when driving down
steep hills. In addition, downshifting at the right time
provides better acceleration when you desire to resume
speed. Downshift progressively. Do not skip gears to
avoid overspeeding the engine and clutch.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip and the vehicle could skid.
CAUTION!
When descending a hill, be very careful to downshift
one gear at a time to prevent overspeeding the engine
which can cause valve damage, and / or clutch disc
damage even if the clutch pedal is depressed.
Maximum Recommended Downshift Speeds
CAUTION!
Failure to follow the recommended downshifting
speeds may cause the engine to overspeed and/or
damage the clutch disc even if the clutch pedal is
depressed.
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This transfer case is intended to be driven in the 2-wheel
drive position (2H) for normal street and highway con-
ditions such as dry hard surfaced roads.
When additional traction is required the transfer case 4H
and 4L positions can be used to lock the front and rear
driveshafts together and force the front and rear wheels
to rotate at the same speed. This is accomplished by
simply moving the shift lever to the desired positions.
The 4H and 4L positions are intended for loose, slippery
road surfaces only. Driving in the 4H and 4L positions on
dry hard surfaced roads may cause increased tire wear
and damage to the driveline components.
The 4-wheel drive light (4WD), located in the instrument
cluster, alerts the driver that the vehicle is in 4-wheel
drive and that the front and rear driveshafts are locked
together. This light illuminates when the transfer case is
shifted to either the 4H or 4L positions. There is no light
for the 2H or NEUTRAL positions.When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions
at a given road speed. Take care not to overspeed the
engine and do not exceed 25 mph (40 km/h).
Proper operation of 4-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can
cause damage to the transfer case.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning. The transfer case is not
equipped with a synchronizer and therefore the front and
rear driveshaft speeds must be equal for the shift to take
place. Shifting while only the front or rear wheels are
spinning can cause damage to the transfer case.
Because 4-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds.
Do not go faster than road conditions permit.
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vehicle in motion, the transfer case will engage/
disengage faster if you momentarily release the accelera-
tor pedal after completing the shift. Apply a constant
force when shifting the transfer case lever.
2H or 4H,4L
With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift
an automatic transmission to NEUTRAL or depress the
clutch on a manual transmission. While the vehicle is
coasting at 2 to 3 mph (3 to 5 km/h), shift the transfer
case lever firmly to the desired position. Do not pause in
transfer case NEUTRAL.
NOTE:Pausing in transfer case NEUTRAL in vehicles
equipped with an automatic transmission may require
shutting the engine OFF to avoid gear clash while
completing the shift. If difficulty occurs, shift automatic
transmission to NEUTRAL, hold foot on brake, and turn
engine OFF. Make shift to the desired mode.NOTE:Shifting into or out of 4L is possible with the
vehicle completely stopped, however difficulty may oc-
cur due to the mating clutch teeth not being properly
aligned. Several attempts may be required for clutch
teeth alignment and shift completion to occur. The pre-
ferred method is with the vehicle rolling 2 to 3 mph (3 to
5 km/h). Avoid attempting to engage or disengage 4L
with the vehicle moving faster than 2 to 3 mph (3 to 5
km/h).
NOTE:Do not attempt to shift to or from 4L while the
transmission is in gear or clutch is engaged.
Transfer Case Reminder Light
The four-wheel drive operating light (4WD), located in
the instrument cluster, is used to alert the driver that the
front axle is fully engaged and all four wheels are
driving.
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If One or More Shift Conditions Are Not Met:
1. The indicator light for the current position will remain
ON.
2. The newly selected position indicator light will con-
tinue to flash.
3. The transfer casewill notshift.
NOTE:Before retrying a selection, make certain that all
the necessary requirements for selecting a new transfer
case position have been met. To retry the selection, turn
the control knob back to the current position, wait five
seconds, and retry selection. To find the shift require-
ments, refer to the9Shifting Procedure9for your transfer
case, located in this section.
The ªSERVICE 4WDº warning light monitors the electric
shift 4WD system. If this light remains on after enginestart up or illuminates during driving, it means that the
4WD system is not functioning properly and that service
is required.
WARNING!
Always engage the parking brake when powering
down the vehicle if the(SERVICE 4WD(light is
illuminated. Not engaging the parking brake may
allow the vehicle to roll, which may cause personal
injury.
NOTE:Do not attempt to make a shift while only the
front or rear wheels are spinning, as this can cause
damage to driveline components.
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When operating your vehicle in 4WD LOW, the engine
speed is approximately three times that of the 2WD or
4WD LOCK positions at a given road speed. Take care
not to overspeed the engine and do not exceed 25 mph
(40 km/h).
Proper operation of 4-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference in tire size can cause damage to the
transfer case.
Because 4-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds.
Do not go faster than road conditions permit.WARNING!
You or others could be injured if you leave the
vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear driveshafts from
the powertrain and will allow the vehicle to move
regardless of the transmission position. The parking
brake should always be applied when the driver is
not in the vehicle.
For additional information on the appropriate use of each
transfer case mode position see the information below:
2WD
Rear Wheel Drive High Range - Normal street and
highway driving. Dry, hard surfaced roads.
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light will continue to flash until all the requirements for
the selected position have been met. To retry a shift:
return the control knob back to the original position,
make certain all shift requirements have been met, wait
five seconds and try the shift again.
NOTE:If all the requirements to select a new transfer
case position have been met, the current position indica-
tor light will turn OFF, the selected position indicator
light will flash until the transfer case completes the shift.
When the shift is complete, the indicator light for the
selected position will stop flashing and remain ON.
2WD,4WD LOCK
Rotate the 4WD control switch to the desired position.
Shifts between 2WD and 4WD LOCK can be done with
the vehicle stopped or in motion. With the vehicle in
motion, the transfer case will engage/disengage faster if
you momentarily release the accelerator pedal after turn-
ing the control switch. If the vehicle is stopped, theignition key must be in the ON position with the engine
either running or off. This shift cannot be completed if the
key is in the ACC position.
NOTE:The 4x4 system will not allow shifts between
2WD/4WD LOCK if the front and/or rear wheels are
spinning (no traction). In this situation the selected
position indicator light will flash and the original posi-
tion indicator light will remain ON. At this time, reduce
speed and stop spinning the wheels to complete the shift.
2WD or 4WD LOCK,4WD LOW
NOTE:When shifting into or out of 4WD LOW some
gear noise may be heard. This noise is normal and is not
detrimental to the vehicle or occupants.
Shifting can be performed with the vehicle rolling 2 to 3
mph (3 to 5 km/h) or completely stopped. USE EITHER
OF THE FOLLOWING PROCEDURES:
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Preferred Procedure
1. With engine running, slow vehicle to 2 to 3 mph (3 to
5 km/h).
2. Shift the transmission into NEUTRAL (depress clutch
on manual transmissions).
3. While still rolling, rotate the transfer case control
switch to the desired position.
4. After the desired position indicator light is ON (not
flashing), shift transmission back into gear (release clutch
on manual transmissions).
Alternate Procedure
1. Bring the vehicle to complete stop.
2. With the key ON and the engine either OFF or
running, shift the transmission into NEUTRAL (depress
clutch on manual transmissions).3. Rotate the transfer case control switch to the desired
position.
4. After the desired position indicator light is ON (not
flashing), shift transmission back into gear (release clutch
on manual transmissions).
NOTE:If steps 1 or 2 of either the Preferred or Alternate
Procedure are not satisfied prior to attempting the shift
then the desired position indicator light will flash con-
tinuously while the original position indicator light is
ON, until all requirements have been met.
NOTE:The ignition key must be ON for a shift to take
place and for the position indicator lights to be operable.
If the key is not ON then the shift will not take place and
no position indicator lights will be on or flashing.
NOTE:If your are leaving your vehicle stored for longer
than 21 days, refer to ªVehicle Storageº in section 7.
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LIMITED-SLIP DIFFERENTIAL Ð IF EQUIPPED
The limited-slip differential provides additional traction
on snow, ice, mud, sand and gravel, particularly when
there is a difference between the traction characteristics
of the surface under the right and left rear wheels. During
normal driving and cornering, the limited-slip unit per-
forms similarly to a conventional differential. On slip-
pery surfaces, however, the differential delivers more of
the driving effort to the rear wheel having the better
traction.
The limited-slip differential is especially helpful during
slippery driving conditions. With both rear wheels on a
slippery surface, a slight application of the accelerator
will supply maximum traction. When starting with only
one rear wheel on an excessively slippery surface, slight
momentary application of the parking brake may be
necessary to gain maximum traction.WARNING!
On vehicles equipped with a limited-slip differen-
tial, never run the engine with one rear wheel off the
ground, since the vehicle may drive through the rear
wheel remaining on the ground. You could lose
control of the vehicle.
Care should be taken to avoid sudden accelerations when
both rear wheels are on a slippery surface. This could
cause both rear wheels to spin, and allow the vehicle to
slide sideways on the crowned surface of a road or in a
turn.
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