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CAUTION!(Continued)
•Your vehicle has been built with improved fluids
that protect the performance and durability of your
vehicle and also allow extended maintenance inter-
vals. Do not use chemical flushes in these compo-
nents as the chemicals can damage your engine,
transmission, power steering or air conditioning.
Such damage is not covered by the New Vehicle
Limited Warranty. If a flush is needed because of
component malfunction, use only the specified
fluid for the flushing procedure.
Engine Oil
Checking Oil Level
To assure proper lubrication of your vehicle’s engine, the
engine oil must be maintained at the correct level. Check
the oil level at regular intervals, such as every fuel stop. The best time to check the engine oil level is about five
minutes after a fully warmed up engine is shut off.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Always
maintain the oil level within the SAFE zone on the
dipstick. Adding one quart of oil when the reading is at
the bottom of the SAFE zone will result in a reading at the
top of the safe zone on these engines.
CAUTION!
Overfilling or underfilling the crankcase will cause
oil aeration or loss of oil pressure. This could damage
your engine.
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To minimize the possibility of catalytic converter damage:
•Do not shut off the engine or interrupt the ignition,
when the transmission is in gear and the vehicle is in
motion.
• Do not try to start the engine by pushing or towing the
vehicle.
• Do not idle the engine with any spark plug wires
disconnected or removed, such as when diagnostic
testing, or for prolonged periods during very rough
idle or malfunctioning operating conditions.
Cooling System
WARNING!
You or others can be badly burned by hot engine
coolant (antifreeze) or steam from your radiator. If
(Continued)
WARNING! (Continued)
you see or hear steam coming from under the hood,
do not 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 the engine coolant (antifreeze) 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 (if equipped) or radiator for any
accumulation of bugs, leaves, etc. If dirty, clean by gently
spraying water from a garden hose vertically down the
face of the A/C condenser (if equipped) or the back of the
radiator core.
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Automatic Transmission — Aisin F21-250 HD
Transmission — If Equipped
Selection Of Lubricant
It is important to use the proper transmission fluid to
ensure optimum transmission performance and life. Use
only the manufacturer ’s specified transmission fluid.
Refer to “Fluids, Lubricants, and Genuine Parts” in this
section for fluid specifications. It is important to maintain
the transmission fluid at the correct level using the
recommended fluid. No chemical flushes should be used
in any transmission; only the approved lubricant should
be used.
CAUTION!
Using a transmission fluid other than the manufac-
turer ’s recommended fluid may cause deterioration
(Continued)
CAUTION!(Continued)
in transmission shift quality and/or torque converter
shudder, and will require more frequent fluid and
filter changes. Refer to “Fluids, Lubricants, and
Genuine Parts” in this section for fluid specifica-
tions.
Special Additives
The manufacturer strongly recommends against using
any special additives in the transmission. Automatic
Transmission Fluid (ATF) is an engineered product and
its performance may be impaired by supplemental addi-
tives. Therefore, do not add any fluid additives to the
transmission. The only exception to this policy is the use
of special dyes for diagnosing fluid leaks. Avoid using
transmission sealers as they may adversely affect seals.
474 MAINTAINING YOUR VEHICLE
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CAUTION!
Do not use chemical flushes in your transmission as
the chemicals can damage your transmission compo-
nents. Such damage is not covered by the New
Vehicle Limited Warranty.
Fluid Level Check
Check the fluid level when the engine is fully warmed up
and the transmission fluid is at normal operating tem-
perature. Driving with an improper fluid level will
greatly reduce the life of the transmission and of the
fluid. Check the fluid level whenever the vehicle is
serviced.
Fluid Level Check — Procedure
It is best to check the fluid level when the transmission is
at normal operating temperature (170-180°F / 77-82°C for
66RFE transmission, or 158–176°F / 70–80°C for AS66RCtransmission). This normally occurs after at least 15 miles
(25 km) of driving. At normal operating temperature the
fluid cannot be held comfortably between the fingertips.
You can read the transmission sump temperature in the
EVIC display (see Electronic Vehicle Information Center
[EVIC] for further information).
Use the following procedure to check the transmission
fluid level properly:
1. Monitor the transmission temperature using the EVIC
display, and operate the vehicle as required to reach
the normal operating temperature.
2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60 seconds, and leave the engine running for the rest of
this procedure.
4. Fully apply the parking brake and press the brake.
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5. Place the shift lever momentarily into each gear posi-tion (allowing time for the transmission to fully en-
gage in each position), ending with the transmission in
PARK.
6. Wipe the area around the dipstick clean to prevent dirt from entering the transmission.
7. Remove the dipstick, wipe it clean and reinsert it until seated.
8. Remove the dipstick again and note the fluid level on both sides. The fluid level reading is only valid if there
is a solid coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full of fluid
if the actual level is at or above the hole. The fluid level
should be between the “HOT” (upper) reference holes
on the dipstick at normal operating temperature. If the
fluid level is low, add fluid through the dipstick tube
to bring it to the proper level. Do not overfill.UseONLY the recommended fluid (see
Fluids, Lubri-
cants, and Genuine Parts for fluid specifications).
After adding any quantity of oil through the dipstick
tube, wait a minimum of two minutes for the oil to
fully drain into the transmission before rechecking the
fluid level.
NOTE: If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the dipstick
with the fluid at 60-70°F / 16-21°C for 66RFE transmis-
sion, or 68-86°F / 20-30°C for AS66RC transmission. Only
use the COLD region of the dipstick as a rough reference
when setting the fluid level after a transmission service
or fluid change. Re-check the fluid level, and adjust as
required, once the transmission reaches normal operating
temperature.
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CAUTION!
If the fluid temperature is below 50°F (10°C) it may
not register on the dipstick. Do not add fluid until
the temperature is elevated enough to produce an
accurate reading. Run the engine at idle, in PARK, to
warm the fluid.
9. Check for leaks. Release the parking brake.
NOTE: To prevent dirt and water from entering the
transmission after checking or replenishing fluid, make
sure that the dipstick cap is properly reseated. It is
normal for the dipstick cap to spring back slightly from
its fully seated position, as long as its seal remains
engaged in the dipstick tube.
Fluid And Filter Changes — Six-Speed
Transmission
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
In addition, change the fluid and filter(s) if the fluid
becomes contaminated (with water, etc.), or if the trans-
mission is disassembled for any reason.
Appearance Care And Protection From Corrosion
Protection Of Body And Paint From Corrosion
Vehicle body care requirements vary according to geo-
graphic locations and usage. Chemicals that make roads
passable in snow and ice, and chemicals that are sprayed
on trees and road surfaces during other seasons, are
highly corrosive to the metal in your vehicle. Outside
parking, which exposes your vehicle to airborne contami-
nants, road surfaces on which the vehicle is operated,
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Cavity Cartridge Fuse Micro FuseDescription
F47 10 Amp RedSnow Plow (Right) – If Equipped
F49 10 Amp RedInstrument Panel Cluster
F50 20 Amp Yellow Air Suspension Control Module – If
Equipped
F51 10 Amp Red Ignition Node Module / Keyless Ignition
F52 5 Amp TanBattery Sensor
F53 20 Amp Yellow Trailer Tow – Left Turn/Stop Lights
F54 20 Amp YellowAdjustable Pedals
F55 20 Amp YellowE38 Radio – If Equipped
F56 15 Amp Blue Additional Diesel Content – If Equipped
F57 20 Amp YellowTransmission
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Chassis
ComponentFluid, Lubricant, or Genuine Part
Automatic Transmission (5.7L, and 6.4L En-
gine with 66RFE Transmission) (For Diesel
Engine see Diesel Supplement) We recommend you use MOPAR® ATF+4® Automatic Transmis-
sion Fluid or equivalent licensed ATF+4® product. Failure to use
ATF+4® fluid may affect the function or performance of your
transmission.
Automatic Transmission (6.4L Engine with
AS66RC Transmission) We recommend you use MOPAR® ASRC Automatic Transmission
Fluid or equivalent. Failure to use the proper fluid may affect the
function or performance of your transmission.
Transfer Case We recommend you use MOPAR® BW44-44 Transfer Case Fluid.
Front and Rear Axle Fluid (4500/5500) We recommend you use GL-5 SAE 75W-90 Synthetic (MS-9763).
Brake Master Cylinder We recommend you use MOPAR® DOT 3 and SAE J1703. If DOT
3 brake fluid is not available, then DOT 4 is acceptable.
Power Steering Reservoir We recommend you use MOPAR® Power Steering Fluid +4,
MOPAR® ATF+4® Automatic Transmission Fluid.
506 MAINTAINING YOUR VEHICLE