cooling DODGE RAM 5500 CHASSIS CAB 2008 3.G Owners Manual

9. Oil Pressure Gauge
The pointer should always indicate some oil pres-
sure when the engine is running. A continuous
high or low reading, under normal driving conditions,
may indicate a lubrication system malfunction. Immedi-
ate service should be obtained.(See page 406 for more
information.)
NOTE:If the gauge pointer moves to either extreme of
the gauge, the ªCheck Gagesº indicator will illuminate
and a single chime will sound.
10. Transfer Case Position
(See page 289 for more information.)
11 .TOW HAUL
The TOW HAUL button is located at the end of the gear
shift lever. This light will illuminate when the TOW
HAUL OD/OFF button is pushed once.(See page 277 for
more information.)12.OD/OFF
the OD/OFF button is located at the end of the gear shift
lever. This light will illuminate when the TOW HAUL
OD/OFF button is pushed twice.(See page 277 for more
information.)
13. Temperature Gauge
The temperature gauge indicates engine coolant
temperature. Any reading within the normal
range indicates that the cooling system is operat-
ing satisfactorily. The gauge needle will likely indicate a
higher temperature when driving in hot weather, up
mountain grades, in heavy traffic, or when towing a
trailer. If the needle rises to the ª245ÉFº mark, stop the
vehicle, shift into N (Neutral), and increase the engine
idle speed for 2 to 3 minutes. If the temperature reading
does not return to normal, shut your engine OFF and
allow it to cool. Seek authorized service immediately. See
Cooling System information in the section on ªMaintain-
ing Your Vehicle.º
176 UNDERSTANDING YOUR INSTRUMENT PANEL

CAUTION!
Do not leave your vehicle unattended with the en-
gine running as you would not be able to react to the
temperature indicator if the engine overheats.
NOTE:Engine idle speed will automatically increase to
1000 rpm at elevated coolant temperatures to improve
engine cooling.
NOTE:If the gauge pointer moves to either extreme of
the gauge, the ªCheck Gagesº indicator will illuminate
and a single chime will sound.
14. Security Light
The light will flash rapidly for approximately 16 seconds
when the vehicle theft alarm is arming. The light willflash at a slower rate after the alarm is set. The security
light will also come on for about two seconds when the
ignition is first turned ON.
15. Transmission Range Indicator (Automatic
Transmissions Only)
When the gear selector lever is moved, this indicator
shows the automatic transmission gear range selected.
16. Odometer/Trip Odometer
The odometer shows the total distance the vehicle has
been driven. U.S. federal regulations require that upon
transfer of vehicle ownership, the seller certify to the
purchaser the correct mileage that the vehicle has been
driven. Therefore, if the odometer reading is changed
during repair or replacement, be sure to keep a record of
the reading before and after the service so that the correct
mileage can be determined.
UNDERSTANDING YOUR INSTRUMENT PANEL 177
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The mode control (at the right of the
control panel) can be set in any of the
following positions:
NOTE:To improve your selection choices, the system
allows you to operate at intermediate positions between
the major modes. These intermediate positions are iden-
tified by the small dots.
Recirculation Modes (Panel or Bi-Level)
Select the recirculation modes when
the outside air contains smoke, odors,
high humidity, or if rapid cooling is
desired. This feature allows for recir-
culation of interior air only. Air flows
through the panel only or throughboth the panel and floor vents depending on the selected
mode (panel vs bi-level).
NOTE:Selecting a ªRecirculation Modeº mode does not
necessarily consume more fuel than normal A/C mode.
Panel
Outside air flows through the outlets located in the
instrument panel.
Bi-Level
Outside air flows through the outlets located in the
instrument panel and at the floor.
Floor
Outside air flows primarily through the floor out-
lets located under the instrument panel.
Mix
Outside air flows in equal proportions through the
floor and defroster outlets, and the air conditioning
may be on.
238 UNDERSTANDING YOUR INSTRUMENT PANEL

Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
UNDERSTANDING YOUR INSTRUMENT PANEL 245
4

NOperating Precautions..................268
NCooling System Tips Ð Automatic
Transmission........................268
mEngine Block Heater (Gas Engines)Ð
If Equipped...........................270
mDiesel Exhaust Brake (Engine Braking) ±
If Equipped...........................270
mAutomatic Transmission..................273
NAutomatic Transmission With Overdrive
(5 Speed 545RFE) Ð If Equipped..........273
NAutomatic Transmission (6 Speed AS68RC) Ð
If Equipped.........................279
mManual Transmission....................285
NManual Transmission Ð 6 Speed (G56)......286
NRecommended Vehicle Shift Speeds........287NDownshifting ± Gas Engine..............288
NDownshifting ± Diesel Engine............288
mFour-Wheel-Drive Operation Ð If Equipped....289
NManually Shifted Transfer Case Operating
Information/Precautions................289
NShifting Procedure Ð Manually Shifted
Transfer Case........................292
NTransfer Case Reminder Light............293
NElectronically Shifted Transfer Case Operating
Information/Precautions (4 Position Switch) Ð
If Equipped.........................294
NShifting Procedure Ð Electronically Shifted
Transfer Case........................298
mLimited-Slip Differential Ð If Equipped.......301
mPower Take Off Operation ± If Equipped......302
248 STARTING AND OPERATING

Winter Front Usage
If a winter front or cold weather cover is to be used, a
percentage of the total grille opening area must be left
uncovered to provide sufficient air flow to the charge air
cooler and automatic transmission oil cooler. The per-
centage of opening must be increased with the increasing
ambient air temperature and/or engine load. If the
cooling fan can be heard cycling frequently, increase the
size of the opening in the winter front. A suitable cold
weather cover is available from your Mopartdealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0ÉF (-18É). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 VAC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized Mopartdealer.
Arctic Operation
Where there are no provisions to keep the engine warm
when it is operating in ambient temperatures consistently
below (-10ÉF/-23ÉC), use 5W-40syntheticengine oil and
fuel that meets the requirements in Section 7, ªMainte-
nance Procedures,º Engine Oil Selection.
Engine Warm-Up
Avoid full throttle operation when the engine is cold.
When starting a cold engine, bring the engine up to
operating speed slowly to allow the oil pressure to
stabilize as the engine warms up.
NOTE:High-speed, no-load running of a cold engine
can result in excessive white smoke and poor engine
performance. No-load engine speeds should be kept
under 1,200 rpm during the warm-up period, especially
in cold ambient temperature conditions.
STARTING AND OPERATING 265
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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.
268 STARTING AND OPERATING

ª1º First
Use this position for driving up very steep hills and for
engine braking at low speeds 20 mph (32 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 25 mph (40 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in ª2º Second or ª1º First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled fourth and fifth speed (Overdrive).
The transmission 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.
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.
276 STARTING AND OPERATING

ª2º Second
Use this position for driving on more severe conditions
and lower speeds than ª3º third. To prevent excessive
engine speed do not exceed 25 mph (40 km/h) in this
range.
ª1º First
Use this position for driving up very steep hills and for
engine braking at low speeds 12 mph (19 km/h) or less
when going downhill. To prevent excessive engine speed,
do not exceed 12 mph (19 km/h) in this range.
NOTE:Use caution when operating a heavily loaded
vehicle in ª2º Second or ª1º First gear selections in high
ambients as torque converter slip can impose significant
additional heat load on the cooling system.
Overdrive Operation
The overdrive automatic transmission contains an elec-
tronically controlled 5th and 6th (if equipped) speed(Overdrive). The transmission 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 38 mph (61
km/h) for 5th gear and 55 mph (89 km/h) for 6th gear;
²the ªTOW HAUL O/D OFFº switch has not been
activated;
²transmission has reached normal operating tempera-
ture.
NOTE:If the vehicle is started in extremely cold tem-
peratures, the transmission shift schedule initially re-
stricts transmission operation in forward gear ranges to
3rd gear until the transmission fluid temperature rises to
282 STARTING AND OPERATING

The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Maintenance
Schedule in section 8 of this manual for transmission
fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the ªTOW HAUL OD/OFFº feature ON when
driving in hilly areas or shift the transmission to Drive
position 2 on more severe grades.
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
STARTING AND OPERATING 363
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