engine DODGE RAM 2500 DIESEL 2004 3.G Repair Manual

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.
FOUR-WHEEL- DRIVE OPERATION Ð IF
EQUIPPED
²
Four-Wheel-Drive Dodge Ram Trucks are equipped
with either a Manually Shifted transfer case or an
Electronically Shifted transfer case. See the operating
instructions for your transfer case, located within this
section.
Manually Shifted Transfer Case Operating
Information/Precautions
The transfer case provides 4 mode positions-2(rear)-
wheel-drive high range, 4-wheel-drive high range, neu-
tral, and 4-wheel-drive low range.
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.
226 STARTING AND OPERATING

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 N (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.
NOTE:Delayed shifts out of four-wheel drive may be
experienced due to uneven tire wear, low or uneven tire
pressures, excessive vehicle loading, or cold tempera-
tures.
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5

Shifting Procedure - Manually Shifted Transfer
Case
2H,4H
Shifting between 2H and 4H can be made with the
vehicle stopped or in motion. If the vehicle is in motion,
shifts can be made up to 55 mph (88 km/h). With thevehicle in motion, the transfer case will engage / disen-
gage faster if you momentarily release the accelerator
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 N (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 N (Neutral).
NOTE:Pausing in transfer case N (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 N (Neutral), hold foot on brake, and turn
engine OFF. Make shift to the desired mode.
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5

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 (5)
seconds, and retry selection. To find the shift require-
ments, refer to the9Shifting Procedure9for your transfer
case, located in this section of the owner's manual.
The ªSERVICE 4WDº warning light monitors the electric
shift 4WD system. If this light remains on after engine
start 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 illu-
minated. 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. 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.
When operating your vehicle in 4LO, the engine speed is
approximately three times that of the 2WD/AWD or 4HI
positions at a given road speed. Take care not to over-
speed 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.
232 STARTING AND OPERATING

return the control knob back to the original position,
make certain all shift requirements have been met, wait
five (5) 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/AWD,4HI
Rotate the 4WD Control Switch to the desired position.
Shifts between 2WD/AWD and 4HI 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 turning
the control switch. If the vehicle is stopped, the ignitionkey must be in the ON position with the engine either
RUNNING or OFF. This shift cannot be completed if the
key is in the accessory position.
NOTE:The 4x4 system will not allow shifts between
(2WD/AWD)/4HI 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/AWD or 4HI,4LO
NOTE:When shifting into or out of 4LO 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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5

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 (de-
press 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 or
if they no longer are being met while the shift attempt is
in process then the desired position indicator light will
flash continuously 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 the section on ªVehicle Storage.º
236 STARTING AND OPERATING

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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5

WARNING!
²Always fully apply the parking brake when leav-
ing your vehicle, or it may roll and cause damage
or injury. Also be certain to leave an automatic
transmission in Park, a manual transmission in
Reverse or first gear. Failure to do so may allow
the vehicle to roll and cause damage or injury.
²Leaving children in a vehicle unattended is dan-
gerous for a number of reasons. A child or others
could be injured. Children should be warned not
to touch the parking brake or the gear selector
lever. Don't leave the keys in the ignition. A child
could operate power windows, other controls, or
move the vehicle.
²Be sure the parking brake is fully disengaged before
driving, failure to do so can lead to brake problems
due to excessive heating of the rear brakes.
When parking on a hill, turn the front wheels toward the
curb on a downhill grade and away from the curb on an
uphill grade.
The parking brake should always be applied whenever
the driver is not in the vehicle.
BRAKE SYSTEM
If power assist is lost for any reason (for example,
repeated brake applications with the engine off), the
brakes will still function. However, you will experience a
substantial increase in braking effort to stop the vehicle.
If either the front or rear hydraulic systems lose normal
capability, the remaining system will still function with
some loss of overall braking effectiveness. This will be
evident by increased pedal travel during application,
greater pedal force required to slow or stop, and activa-
tion of the BRAKE warning lamp and the ABS lamp (if
equipped) during brake use.
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Radial-Ply Tires
WARNING!
Combining radial ply tires with other types of tires
on your vehicle will cause your vehicle to handle
poorly. The instability could cause an accident. Al-
ways use radial ply tires in sets of four (or 6, in case
of trucks with dual rear wheels). Never combine
them with other types of tires.
Cuts and punctures in radial tires are repairable only in
the tread area because of sidewall flexing. Consult your
authorized tire dealer for radial tire repairs.
Compact Spare Tire Ð If Equipped
The compact spare is for temporary emergency use with
radial tires. It is engineered to be used on your style
vehicle only. Since this tire has limited tread life, the
original tire should be repaired (or replaced) and rein-
stalled at the first opportunity.
WARNING!
Temporary use spare tires are for emergency use
only. With these tires, do not drive more than 50 mph
(80 km/h). Temporary-use spare tires have limited
tread life. When two or more tread wear indicators
appear in adjacent grooves, the temporary use spare
tire needs to be replaced. Be sure to follow the
warnings which apply to your spare. Failure to do so
could result in spare tire failure and loss of vehicle
control.
STARTING AND OPERATING 255
5

ENGINE RUNAWAY
WARNING!
In case of engine runaway due to flammable fumes
from gasoline spills or turbocharger oil leaks being
sucked into the engine do the following to help
avoid personal injury and/or vehicle damage:
1. Shut off engine ignition switch.
2. Using a CO
2or dry chemical type fire extin-
guisher, direct the spray from the fire extinguisher
into the grille on the passenger side so that the spray
enters the engine air intake.
The inlet for the engine air intake is located behind the
passenger side headlamp and receives air through the
grille
FUEL REQUIREMENTS
Use good quality diesel fuel from a reputable supplier in
your Dodge truck. For most year-round service, No. 2
diesel fuel meeting ASTM specification D-975 will pro-
vide good performance. If the vehicle is exposed to
extreme cold (below 20ÉF or -7ÉC), or is required to
operate at colder-than-normal conditions for prolonged
periods, use climatized No. 2 diesel fuel or dilute the No.
2 diesel fuel with 50% No. 1 diesel fuel. This will provide
better protection from fuel gelling or wax-plugging of the
fuel filters.
WARNING!
Do not use alcohol or gasoline as a fuel blending
agent. They can be unstable under certain conditions
and hazardous or explosive when mixed with diesel
fuel.
264 STARTING AND OPERATING