2008 DODGE RAM 3500 CHASSIS CAB trailer

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
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NAlignment And Balance.................332
mSupplemental Tire Pressure Information Ð If
Equipped............................333
mTire Chains...........................333
mSnow Tires...........................334
mTire Rotation Recommendations............335
NDual Rear Wheels.....................336
mEngine Runaway.......................337
mFuel Requirements......................337
NFuel Requirements (5.7L Gas Engines).......337
NFuel Requirements (6.7L Diesel Engines).....341
mAdding Fuel..........................343
NAdding Fuel (Gas Engines)..............343NAdding Fuel (Diesel Engines).............345
mVehicle Loading........................347
NCertification Label.....................347
mTrailer Towing.........................351
NCommon Towing Definitions.............351
NTrailer Hitch Classification...............355
NTrailer Towing Weights (Maximum Trailer
Weight Ratings)......................356
NTrailer And Tongue Weight..............356
NTowing Requirements..................357
NTowing Tips.........................362
NTrailer Towing Mirrors Ð If Equipped......364
mSnowplow............................365
250 STARTING AND OPERATING

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 ªTOW HAULº and ªO/D OFFº
Modes
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the ªTOW HAUL O/D OFFº button once to
select TOW HAUL. This will improve performance and
Tow Haul O/D Off Switch
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5

reduce the potential for transmission overheating or
failure due to excessive shifting. When operating in
ªTOW HAULº mode, 5th gear is disabled and 2-3 and 3-4
shift patterns are modified. Shifts into Overdrive (4th
gear) are allowed during steady cruise (for improved fuel
economy) and automatic closed-throttle downshifts to
3rd gear (for improved braking) will occur during steady
braking. Pressing the ªTOW HAUL O/D OFFº button a
second time to select O/D OFF will disable 4th and 5th
gear completely, which should eliminate any excessive
transmission shifting.
The ªTOW HAULº or ªO/D OFFº light will illuminate in
the instrument cluster to indicate when the switch has
been activated. Pressing the switch a third time restores
normal operation. If the ªTOW HAULº or ªO/D OFFº
modes are desired, the button must be pressed each time
the engine is started.When To Lock Out Overdrive
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent 4±3±4 transmission shifting
occurs, press the ªTOW/HAULº button twice to disable
the overdrive. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting.
Torque Converter Clutch
A feature, designed to improve fuel economy, has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
high gear. When the vehicle speed drops or during
acceleration when the transmission downshifts to second
gear, the clutch automatically disengages.
278 STARTING AND OPERATING

a suitable level. During this condition, the ability of the
vehicle to accelerate under heavily loaded conditions
may be reduced. 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 37 mph (60 km/h) for 6th to
5th and 29 mph (47 km/h) for 5th to 4th.When To Use ªTOW HAULº and ªO/D OFFº
Modes
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the ªTOW HAUL O/D OFFº button once to
select TOW HAUL. This will improve performance and
Tow Haul O/D Off Switch
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5

reduce the potential for transmission overheating or
failure due to excessive shifting. When operating in
ªTOW HAULº mode, 6th gear (if equipped) is disabled
and 2-3 and 3-4 and 4±5 shift patterns are modified. Shifts
into Overdrive (5th gear) are allowed during steady
cruise (for improved fuel economy). Pressing the ªTOW
HAUL O/D OFFº button a second time to select O/D
OFF will disable 5th and 6th gear completely, which
should eliminate any excessive transmission shifting.
The ªTOW HAULº or ªO/D OFFº light will illuminate in
the instrument cluster to indicate when the switch has
been activated. Pressing the switch a third time restores
normal operation. If the ªTOW HAULº or ªO/D OFFº
modes are desired, the button must be pressed each time
the engine is started.WARNING!
Do not use the Tow/Haul feature when driving in icy
or slippery conditions as the increased engine brak-
ing 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 possibly result-
ing in personal injury or death.
When To Lock Out Overdrive
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent 6±5±6 or 5±4±5 transmis-
sion shifting occurs, press the ªTOW/HAULº button.
This will improve performance and reduce the potential
for transmission overheating or failure due to excessive
shifting.
284 STARTING AND OPERATING

Truck models with manual transmission are equipped
with a clutch interlocking ignition system. The clutch
pedal must be fully depressed to start the vehicle.
Fully depress the clutch pedal before shifting gears. As
you release the clutch pedal, lightly depress the accelera-
tor pedal.
To shift into Reverse, come to a complete stop. Depress
the clutch and pause briefly to allow the gear train to
stop. Move the shift lever from the Neutral position
straight across and back into Reverse.
Never drive with your foot resting on the clutch pedal, or
attempt to hold the vehicle on a hill with the clutch pedal
partially engaged, as this will cause abnormal wear on
the clutch.Manual Transmission Ð 6 Speed (G56)
Your vehicle may be equipped with the G56 manual
transmission. This transmission has a ªcreeperº 1st gear
which should be used to start from a standing position
when carrying a payload or towing a trailer. Damage to
the clutch can result from starting in 2nd or 3rd gear with
a loaded vehicle. An unloaded vehicle may be launched
in 2nd gear. Use each gear in numerical order ± do not
skip a gear.
For most city driving you may find it easier to use only
1st through 5th gear ranges. For steady highway driving
with light accelerations, 6th gear is recommended. To
shift into 5th gear, move the shift lever to the right
beyond the spring pressure point and push it forward.
When shifting from 5th to 4th gear, pull the lever down
toward you in one motion. Do not pull the lever sharply
left as you may shift accidentally into 2nd gear and
damage the transmission.
286 STARTING AND OPERATING

6. Do not use trailer tow mode on vehicle's with the
AISIN 6 speed automatic transmission (6.7L Diesel En-
gine only).
DRIVING THROUGH WATER
Driving through water more than a few inches deep will
require extra caution to ensure safety and prevent dam-
age to your vehicle.
Flowing/Rising Water
WARNING!
Do not drive on or cross a road or a path where water
is flowing and/or rising (as in storm run-off). Flow-
ing water can wear away the road or path's surface
and cause your vehicle to sink into deeper water.
Furthermore, flowing and/or rising water can carry
your vehicle away swiftly. Failure to follow this
warning may result in injuries that are serious or
fatal to you, your passengers, and others around you.
Shallow Standing Water
Although your vehicle is capable of driving through
shallow standing water, consider the following before
doing so:
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