2008 DODGE RAM 3500 CHASSIS CAB cooling

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
5

þAir Conditioning
Turn off temporarily.
þrefer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
Trailer Towing Mirrors Ð If Equipped
These mirrors are designed with an adjustable mirror
head to provide a greater vision range when towing
extra-wide loads. To change position inboard or out-
board, the mirror head should be rotated (flipped Out or
In). A small blindspot mirror is integrated onto the main
mirror surface.
NOTE: Fold the7x10inch trailer towing mirrors
rearward prior to entering an automated car wash.
Blindspot Mirror
364 STARTING AND OPERATING

NCatalytic Converter (Gas Engines).........420
NIntervention Regeneration Strategy ± EVIC
Message Process Flow (Catalyst Full Message)
(Diesel Engines Only)..................422
NEmission-Related Components (Gas Engines) . . 425
NMaintenance Free Battery (Gas Engines).....425
NMaintenance Free Batteries (Diesel Engines) . . . 426
NAir Conditioner Maintenance.............427
NPower Steering Ð Fluid Check............428
NFront Suspension Ball Joints..............429
NSteering Linkage Ð Inspection............429
NFront Prop Shaft Lubrication.............430
NFront Axle Universal Drive Joints And
Ball Joints...........................430NBody Lubrication.....................430
NWindshield Wiper Blades................431
NWindshield Washers...................431
NExhaust System......................432
NCooling System.......................433
NFan ...............................439
NCharge Air Cooler Ð Inter-Cooler
(Diesel Engines)......................439
NHoses And Vacuum/Vapor Harnesses.......440
NFuel System Connections................440
NBrake System........................440
NClutch Hydraulic System................443
NClutch Linkage.......................443
398 MAINTAINING YOUR VEHICLE

²If you have your vehicle undercoated, make sure no
undercoating material is sprayed on the exhaust sys-
tem or components of the seat belt system.
NOTE:It is not possible for the manufacturer and
Cummins, Inc. to anticipate every possible circumstance
that can involve a potential hazard.
WARNING!
To maintain your vehicle safely and avoid personal
injury, follow these guidelines:
²Never spray or pour diesel fuel, flammable liquid or
starting fluids (ether) into the air cleaner assembly, air
intake piping or turbocharger inlet in an attempt to
start the vehicle, unintended engine acceleration may
occur.
²Do not use alcohol or gasoline as a fuel blending agent.
They can be unstable under certain conditions and be
hazardous or explosive when mixed with diesel fuel.
²If an engine has been operating and the coolant is hot,
allow the engine to cool before you slowly loosen the
filler cap and relieve the pressure from the cooling
system.
²To avoid burns, remember that the engine components
will stay hot after the engine is shut off.
²Do not use gasoline or other flammable materials to
clean parts. Always use approved cleaning solvents.
²Relieve all pressure in the fuel, oil and cooling systems
before any lines, fittings or related items are removed
or disconnected. Be alert for possible pressure when
disconnecting any device from a system that utilizes
MAINTAINING YOUR VEHICLE 405
7

Use a container that can hold at least 12 quarts (11.3
Liters) to hold the used oil.
Always check the condition of the used oil. This can give
you an indication of some engine problems that might
exist.
²Thin, black oil indicates fuel dilution.
²Milky discoloration indicates coolant dilution.
Clean the area around the oil filter base. Remove the filter
from the underside of the vehicle using a cap style oil
filter wrench.
Clean the gasket surface of the filter mount. The filter
gasket can stick on the filter mount. Make sure it is
removed.
Change the engine oil filter with every engine oil change.
Only a high quality MOPAR filter should be used to
assure most efficient service.
CAUTION!
The filtering medium of other aftermarket filters
may disintegrate. Debris from failed filters may plug
the piston oil cooling nozzles, resulting in scuffed
pistons and engine failure.
CAUTION!
Fill the oil filter element with clean oil before instal-
lation. Use the same type oil that will be used in the
engine. When filling the oil filter, prevent foreign
material from falling into the filter. Severe engine
damage may occur.
Apply a light film of lubricating oil to the sealing surface
of the filter gasket before installing the filter.
MAINTAINING YOUR VEHICLE 411
7

WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO) which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison you. To avoid breathing CO, fol-
low the preceding safety tips.
Exhaust System Rubber Isolator and Loop-Type
Hanger Ð If Equipped
Inspect surfaces whenever the vehicle is hoisted for
rubber to metal separation or deep cracks. If, however,
excessively deep localized cracks are present, or any part
of the exhaust system abnormally contacts the under-
body hardware, the isolator and/or hanger should be
replaced.
Cooling System
WARNING!
You or others can be badly burned by hot coolant or
steam from your radiator. If you see or hear steam
coming from under the hood, don't open the hood
until the radiator has had time to cool. Never try to
open a cooling system pressure cap when the radiator
is hot.
Engine Coolant Checks
Check the engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
coolant. Check the front of the A/C condenser for any
MAINTAINING YOUR VEHICLE 433
7

accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the condenser.
Check the coolant recovery bottle tubing for brittle rub-
ber, cracking, tears, cuts and tightness of the connection
at the bottle and radiator. Inspect the entire system for
leaks.
Extremely cold ambient temperature may require the
addition of a ªwinter frontº for effective operation of the
cab heating/cooling system. Make certain that a percent-
age of the radiator is exposed for adequate air flow
through the charge air cooler and automatic transmission
oil cooler. The percentage 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.Coolant bottle level check
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling, and warmed to the normal
operating temperature, the level of the coolant on the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.
The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.
WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool overheated engine! The coolant is under pres-
sure and severe scalding could result.
434 MAINTAINING YOUR VEHICLE