DODGE RAM 3500 DIESEL 2008 3.G Owners Manual

NOTE:An optional driver-controlled high idle speed is
available on automatic transmission equipped vehicles
with speed control. This feature allows the driver to
select an elevated idle speed between 1100 and 1500
rpms. Your dealer can enable this feature.
The optional driver-controlled high idle speed will help
increase cylinder temperatures and provide additional
cab heat, however, may still cause the exhaust aftertreat-
ment system to not properly regenerate. Extended peri-
ods of idle time should be avoided.
NOTE:
²If ambient temperatures are low and the coolant
temperature is below 200ÉF (93ÉC), the engine idle
speed will slowly increase to 1000 RPM after 2 minutes
of idle, if the following conditions are met:
²foot is off brake pedal and throttle pedal
²automatic transmission is in Park (P)
²vehicle speed is zero
²Applying the throttle will cancel fast idle
²If the engine is equipped with an exhaust brake,
operating the exhaust brake at idle will greatly im-
prove warm up rate and will help keep the engine
close to operating temperature during extended idle.
CAUTION!
Use of aftermarket exhaust brakes is not recom-
mended and could lead to engine damage
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5

Stopping The Engine
Idle the engine a few minutes before routine shutdown.
After full load operation, idle the engine 3 to 5 minutes
before shutting it down. This idle period will allow the
lubricating oil and coolant to carry excess heat away from
the combustion chamber, bearings, internal components,
and turbocharger. This is especially important for turbo-
charged, charge air cooled engines.
NOTE:During engine shutdown on vehicles equipped
with manual transmissions, it is normal for the diesel
engine to resonate heavily for a moment during engine
shut off. When the engine is connected to a manual
transmission, this resonance causes loud gear rattle from
the transmission. This is commonly referred to as ªshut
down rattleº. The manufacturer recommends performing
engine shut down with the clutch pedal pushed to the
floor (clutch disengaged). When engine shut down is
performed in this manner the rattle is reduced (not
eliminated).Driving
ConditionLoadTurbo-
charger
TemperatureIdle Time
(min.) Be-
fore Engine
Shutdown
Stop and
GoEmpty Cool Less than
One
Stop and
GoMedium One
Highway
SpeedsMedium Warm Two
City Traffic Maximum
GCWRThree
Highway
SpeedsMaximum
GCWRFour
Uphill
GradeMaximum
GCWRHot Five
280 STARTING AND OPERATING

Engine Speed Control
CAUTION!
Prevent overspeeding the engine going down hill.
When descending steep grades, use a combination of
gears and service brakes to control vehicle/engine
speed. Overspeed can cause severe engine damage.
Operating Precautions
Avoid Overheating The Engine
The temperature of the coolant (a mixture of 50%
ethylene-glycol and 50% water) must not exceed the
normal range of the temperature gauge (240ÉF/116ÉC)
with a 16 psi (110 kPa) radiator cap.
Usually the coolant temperature indicated during opera-
tion will be to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low coolant temperature below
the normal range on the gauge (140ÉF/60ÉC) can be
harmful to the engine. Low coolant temperature can
cause incomplete combustion which allows carbon and
varnish to form on piston rings and injector nozzles.
Also, the unburned fuel can enter the crankcase, diluting
the lubricating oil and causing rapid wear to the engine.
Cooling System Tips Ð Automatic Transmission
To reduce potential for engine and transmission over-
heating in high ambient temperature conditions, take the
following actions:
²City Driving Ð
when stopped, put transmission in neutral and increase
engine idle speed.
²Highway Driving Ð
reduce your speed.
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5

²Up Steep Hills Ð
select a lower transmission gear, but try and keep the
torque converter clutch engaged.
²Air Conditioning Ð
turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating temperature, the
minimum oil pressures required are:
Idle 700 to 800 RPM............... 10psi(69kPa)
Full speed and load.............. 30psi(207 kPa)
CAUTION!
If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could
result in immediate and severe engine damage.
Do Not Operate The Engine With Failed Parts
Practically all failures give some warning before the parts
fail. Be on the alert for changes in performance, sounds,
and visual evidence that the engine requires service.
Some important clues are:
²engine misfiring or vibrating severely
²sudden loss of power
²unusual engine noises
²fuel, oil or coolant leaks
²sudden change, outside the normal operating range, in
the engine operating temperature
²excessive smoke
²oil pressure drop
282 STARTING AND OPERATING

DIESEL EXHAUST BRAKE (ENGINE BRAKING) ±
IF EQUIPPED
The exhaust brake feature will only function when the
driver turns the exhaust brake switch to the ON position.
Once the switch is in the ON position and the vehicle is
moving faster than 5 mph (8 km/h); the exhaust brake
will automatically operate when the driver removes
pressure from the accelerator pedal. Exhaust braking is
most effective when the engine RPM is higher. The
automatic transmission has been programmed to down-
shift more aggressively when the exhaust brake is en-
abled to increase brake performance.
Exhaust Brake Switch
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5

WARNING!
Do not use the Exhaust Brake feature when driving
in icy or slippery conditions as the increased engine
braking can cause the rear wheels to slide and the
vehicle to swing around with the possible loss of
vehicle control, which may cause an accident possi-
bly resulting in personal injury or death.
NOTE:For optimum braking power it is recommended
to use the Exhaust Brake while in Tow/Haul Mode.
The purpose of the exhaust brake (engine braking) fea-
ture is to supply negative (braking) torque to the engine.
Typically, the engine braking is used for, but not limited
to, vehicle towing applications where vehicle braking can
be achieved by the internal engine power, thereby spar-
ing the mechanical brakes of the vehicle.Benefits of the exhaust brake are:²vehicle driving control
²reduced brake fade
²longer brake life
²faster cab warm-up.
The exhaust brake feature can also be used to reduce the
engine warm up time. To use the exhaust brake as a
warm-up device, the vehicle must be moving less than 5
mph (8 km/h), the exhaust brake switch must be in the
ON position, and the coolant temperature must below
180ÉF (82ÉC) and ambient temperature below 60ÉF (16ÉC).
284 STARTING AND OPERATING

TRANSMISSION SHIFTING
Automatic Transmission with Overdrive
(68RFE) Ð If Equipped
The gear selector lever display located in the instrument
panel cluster indicates the transmission gear range (the
selector is illuminated for night driving). The selector
lever is mounted on the right side of the steering column.
You must depress the brake pedal to pull the selector
lever out of PARK position (Brake Interlock System). To
drive, move the selector lever from PARK or NEUTRAL
to the desired DRIVE position. Pull the selector lever
toward you when shifting into REVERSE, SECOND,
FIRST or PARK, or when shifting out of PARK.
Gear Ranges
DO NOT race the engine when shifting from PARK or
NEUTRAL position into another gear range.PARK
This gear position supplements the parking brake by
locking the transmission. The engine can be started in
this range. Never use PARK while the vehicle is in
motion. Apply the parking brake when leaving the
vehicle in this range. Always apply parking brake first,
then place the selector in PARK position. On 4-wheel
drive vehicles be sure that the transfer case is in a drive
position!
WARNING!
Never use PARK position on an automatic transmis-
sion as a substitute for the parking brake. Always
apply parking brake fully when parked to guard
against vehicle movement and possible injury or
damage.
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5

WARNING!
Your vehicle could move and injure you and others if
it is not completely in PARK. Check by trying to
move the shift lever back and forth without first
pulling it toward you after you have set it in PARK.
Make sure it is in PARK before leaving the vehicle.
WARNING!
It is dangerous to shift the shift lever out of PARK or
NEUTRAL if the engine speed is higher than idle
speed. If your foot is not firmly on the brake pedal,
the vehicle could accelerate quickly forward or in
reverse. You could lose control of the vehicle and hit
someone or something. Only shift into gear when the
engine is idling normally and when your right foot is
firmly on the brake pedal.REVERSE
Use this range only after the vehicle has come to a
complete stop.
NEUTRAL
Shift to NEUTRAL when the vehicle is standing for
prolonged periods with the engine running. The engine
may be started in this range. Set the parking brake if you
must leave the vehicle.
DRIVE
Drive range provides underdrive 1st, 2nd and 3rd gears,
direct 4th gear and overdrive 5th and 6th gears. The shift
into overdrive 5th and 6th gear occurs only after the
transmission has completed the shift into 4th gear. No
other movement of the shift mechanism is required to
complete the 4±5 or 5±6 gear shifts.
The 4th and 5th gear upshifts occurs automatically unless
the Tow/Haul mode is enabled.
286 STARTING AND OPERATING

Upshifts into both overdrive gears, 5th and 6th, will be
delayed when the transmission fluid temperature is
below 40É F (4.5É C) or above 240É F (115.5É C).
NOTE:Use caution when operating a heavily loaded
vehicle in 2nd or 1st gear in high ambients as torque
converter slip can impose significant additional heat load
on the cooling system.
WARNING!
Never use Park position on an automatic transmis-
sion as a substitute for the parking brake. Always
apply parking brake fully when parked to guard
against vehicle movement and possible injury or
damage.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled 5th and 6th (Overdrive). The trans-
mission will automatically shift from Drive to Overdrive
if the following conditions are present:
²the transmission selector is in DRIVE;
²the engine coolant has reached normal operating tem-
perature;
²vehicle speed is above approximately 30 mph (48
km/h);
²the ªTOW HAUL O/D OFFº switch has not been
activated;
²transmission has reached normal operating tempera-
ture.
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5

NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission may not shift into Overdrive
and will automatically select the most desirable gear for
operation at this temperature. Normal operation will
resume when the transmission fluid temperature has
risen to a suitable level. Refer also to the Note under
torque converter clutch, later in this section.
If the transmission temperature gets extremely hot, the
transmission will automatically select the most desirable
gear for operation at this temperature. If the transmission
temperature becomes hot enough the TRANS TEMP light
may illuminate and the transmission may downshift out
of Overdrive until the transmission cools down. After
cooldown, the transmission will resume normal opera-
tion.
The transmission will downshift from Overdrive to Drive
if the accelerator pedal is fully depressed at vehicle
speeds above approximately 35 mph (56 km/h).When To Use TOW HAUL
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the TOW HAUL button once to select TOW
HAUL. In TOW HAUL mode, 4th to 5th gear upshifts are
1 Ð Tow/Haul Switch
2 Ð AUTO-6 (ERS) Switch 288 STARTING AND OPERATING