440 SERVICING AND MAINTENANCE
Fluid Level Check — Eight-Speed Transmission
The fluid level is preset at the factory and does not require
adjustment under normal operating conditions. Routine
fluid level checks are not required, therefore the transmis-
sion has no dipstick. An authorized dealer can check your
transmission fluid level using special service tools.
If you notice fluid leakage or transmission malfunction, visit
an authorized dealer immediately to have the transmission
fluid level checked. Operating the vehicle with an improper
fluid level can cause severe transmission damage. Fluid Level Check — Six-Speed Transmission
It is best to check the fluid level when the transmission is at
normal operating temperature (158-176°F / 70-80°C). 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 trans
-
mission sump temperature in the instrument cluster screen
(refer to “Instrument Cluster Display” for further informa -
tion).
Use the following procedure to check the transmission fluid
level properly:
1. Monitor the transmission temperature using the instru -
ment cluster display, and operate the vehicle as required
to reach the normal operating temperature. If the trans-
mission is not functioning properly, or the vehicle cannot
be driven, see the NOTE and CAUTION below about
checking the fluid level at colder temperatures.
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 pedal.
CAUTION!
Do not use chemical flushes in your transmission as the
chemicals can damage your transmission components.
Such damage is not covered by the New Vehicle Limited
Warranty.
CAUTION!
If a transmission fluid leak occurs, visit an authorized
dealer immediately. Severe transmission damage may
occur. An authorized dealer has the proper tools to adjust
the fluid level accurately.
SERVICING AND MAINTENANCE 441
5. Place the gear selector momentarily into each gear posi-
tion (allowing time for the transmission to fully engage in
each position), ending with the transmission in PARK.
6. Remove the dipstick, wipe it clean and reinsert it until seated.
7. 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. Use ONLY the spec -
ified fluid (see "Fluids And Lubricants" for fluid specifica -
tions). 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 oper -
ating 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. Only use the COLD region of the dipstick as a rough reference when setting the fluid level after a trans
-
mission service or fluid change. Re-check the fluid level, and
adjust as required, once the transmission reaches normal
operating temperature.
8. Reinsert the dipstick. Check for leaks. Release the parking brake.
NOTE:
If it is necessary to check the transmission below the oper -
ating temperature, the fluid level should be between the two
COLD (lower) holes on the dipstick with the fluid at 68-86°F
/ 20-30°C. Only use the COLD region of the dipstick as a
rough reference when setting the fluid level after a transmis -
sion service or fluid change. Re-check the fluid level, and
adjust as required, once the transmission reaches normal
operating temperature. 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.
7
442 SERVICING AND MAINTENANCE
Fluid And Filter Changes — Eight-Speed Transmission
Under normal operating conditions, the fluid installed at the
factory will provide satisfactory lubrication for the life of the
vehicle.
Routine fluid and filter changes are not required. However,
change the fluid and filter if the fluid becomes contaminated
(with water, etc.), or if the transmission is disassembled for
any reason.
Fluid And Filter Changes — Six Speed Transmission
Refer to the “Maintenance Plan” for the proper maintenance
intervals.
In addition, change the fluid and filters if the fluid becomes
contaminated (with water, etc.), or if the transmission is
disassembled for any reason.
Rear Axle And 4x4 Front Driving Axle Fluid Level
For models with 9.25 in Front Axles and 11.5 in Rear Axles,
refer to “Fluids And Lubricants” in “Servicing And Mainte-
nance” for further information. For normal service, periodic
fluid level checks are not required. When the vehicle is
serviced for other reasons, the exterior surfaces of the axle
assembly should be inspected.
When checking the fluid level, the vehicle should be in a
level position. The fluid level at room temperature should be
as follows:
3500 Front Axle: ¼ in ± ¼ in (6.4 mm ± 6.4 mm) below the
bottom of the fill hole.
3500 Rear Axle: ¼ in ± ¼ in (6.4 mm ± 6.4 mm) below the
bottom of the fill hole.
4500/5500 Front Axle: ¼ in +/- ¼ in (6.4 mm ± 6.4 mm)
below the bottom of the fill hole.
4500/5500 Rear Axle: 1/8 in +/- 1/8 in (3.2 mm +/- 3.2 mm)
below the bottom of the fill hole.
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.
476 TECHNICAL SPECIFICATIONS
BRAKE SYSTEM
If power assist is lost for any reason (for example, repeated
brake applications with the engine off), the brakes will still
function. However, you will experience a substantial
increase in braking effort to stop the vehicle.
If either the front or rear hydraulic system loses normal
braking capability, the remaining system will still function
with some loss of overall braking effectiveness. This will be
evident by increased pedal travel during application, greater
pedal force required to slow or stop, and activation of the
“Brake Warning Light” and the “ABS Warning Light” (if
equipped) during brake use.
The brake system power assist is provided by a hydro-boost
unit which shares fluid with the power steering system. You
may experience some clicking or hissing noises from the
hydro-boost system during hard braking conditions.
NOTE:
Under cold temperatures, pedal effort will be higher than
normal until the power steering fluid reaches operating
temperature.
Hydraulic Brake Assist
The brake system power assist is provided by a hydro-boost
unit which shares fluid with the power steering system. You
may experience some clicking or hissing noises from the
hydro-boost system during hard braking conditions.
NOTE:
Under cold temperatures, pedal effort will be higher than
normal until the power steering fluid reaches operating
temperature.
WHEEL AND TIRE TORQUE SPECIFICATIONS
Proper lug nut/bolt torque is very important to ensure that
the wheel is properly mounted to the vehicle. Any time a
wheel has been removed and reinstalled on the vehicle, the
lug nuts/bolts should be torqued using a properly calibrated
torque wrench using a high quality six sided (hex) deep wall
socket.
TECHNICAL SPECIFICATIONS 479
The wheel nuts should then be tightened to recommended
torque. Tighten the wheel nuts to final torque in increments.
Progress around the bolt circle, tightening the wheel nut
opposite to the wheel nut just previously tightened until
final torque is achieved.
FUEL REQUIREMENTS
6.4L Engine
Do not use E-85 flex fuel or ethanol blends greater than 15%
in this engine.This engines is designed to meet all emissions regu -
lations and provide satisfactory fuel economy and
performance when using high quality unleaded
gasoline having a posted octane number range of 87 to 89 as
specified by the (R+M)/2 method. The use of 89 octane
“Plus” gasoline is recommended for optimum performance
and fuel economy. While operating on gasoline with an octane number of 87,
hearing a light knocking sound from the engine is not a cause
for concern. However, if the engine is heard making a heavy
knocking sound, see your dealer immediately. Use of gaso
-
line with an octane number lower than 87 can cause engine
failure and may void or not be covered by the New Vehicle
Limited Warranty.
Poor quality gasoline can cause problems such as hard
starting, stalling, and hesitations. If you experience these
symptoms, try another brand of gasoline before considering
service for the vehicle.
Reformulated Gasoline
Many areas of the country require the use of cleaner burning
gasoline referred to as “Reformulated Gasoline”. Reformu-
lated gasoline contains oxygenates and are specifically
blended to reduce vehicle emissions and improve air quality.
The use of reformulated gasoline is recommended. Properly
blended reformulated gasoline will provide improved
performance and durability of engine and fuel system
components.
WARNING!
To avoid the risk of forcing the vehicle off the jack, do
not tighten the lug nuts/bolts fully until the vehicle has
been lowered. Failure to follow this warning may result
in personal injury.
8
480 TECHNICAL SPECIFICATIONS
Materials Added To Fuel
Besides using unleaded gasoline with the proper octane
rating, gasolines that contain detergents, corrosion and
stability additives are recommended. Using gasolines that
have these additives will help improve fuel economy, reduce
emissions, and maintain vehicle performance.Designated TOP TIER Detergent Gasoline contains a
higher level of detergents to further aide in mini -
mizing engine and fuel system deposits. When avail -
able, the usage of TOP TIER Detergent gasoline is
recommended. Visit www.toptiergas.com for a list of TOP
TIER Detergent Gasoline Retailers.
Indiscriminate use of fuel system cleaning agents should be
avoided. Many of these materials intended for gum and
varnish removal may contain active solvents or similar
ingredients. These can harm fuel system gasket and
diaphragm materials.
Gasoline/Oxygenate Blends
Some fuel suppliers blend unleaded gasoline with oxygen -
ates such as ethanol.
Problems that result from using gasoline containing more
than 15% ethanol (E-15) or gasoline containing methanol are
not the responsibility of the manufacturer and may void or
not be covered under New Vehicle Limited Warranty.
CAUTION!
DO NOT use E-85, gasoline containing methanol, or
gasoline containing more than 15% ethanol (E-15). Use of
these blends may result in starting and drivability
problems, damage critical fuel system components, cause
emissions to exceed the applicable standard, and/or
cause the Malfunction Indicator Light to illuminate.
Please observe pump labels as they should clearly
communicate if a fuel contains greater than 15% ethanol
(E-15).
TECHNICAL SPECIFICATIONS 481
(Continued)
Do Not Use E-85 In Non-Flex Fuel Vehicles
Non-Flex Fuel Vehicles (FFV) are compatible with gasoline
containing up to 15% ethanol (E-15). Use of gasoline with
higher ethanol content may void the New Vehicle Limited
Warranty.
If a Non-FFV vehicle is inadvertently fueled with E-85 fuel,
the engine will have some or all of these symptoms:
• Operate in a lean mode.
• OBD II Malfunction Indicator Light on.
• Poor engine performance.
• Poor cold start and cold drivability.
• Increased risk for fuel system component corrosion.
CNG And LP Fuel System Modifications
Modifications that allow the engine to run on Compressed
Natural Gas (CNG) or Liquid Propane (LP) may result in
damage to the engine, emissions, and fuel system compo-
nents. Problems that result from running CNG or LP are not
the responsibility of the manufacturer and may void or not
be covered under the New Vehicle Limited Warranty.
MMT In Gasoline
Methylcyclopentadienyl Manganese Tricarbonyl (MMT) is a
manganese-containing metallic additive that is blended into
some gasoline to increase octane. Gasoline blended with
MMT provides no performance advantage beyond gasoline
of the same octane number without MMT. Gasoline blended
with MMT reduces spark plug life and reduces emissions
system performance in some vehicles. The manufacturer
recommends that gasoline without MMT be used in your
vehicle. The MMT content of gasoline may not be indicated
on the gasoline pump; therefore, you should ask your gaso -
line retailer whether the gasoline contains MMT. MMT is
prohibited in Federal and California reformulated gasoline.
Fuel System Cautions
CAUTION!
Follow these guidelines to maintain your vehicle’s
performance:
• The use of leaded gasoline is prohibited by Federal law. Using leaded gasoline can impair engine perfor -
mance and damage the emissions control system.
8
482 TECHNICAL SPECIFICATIONS
NOTE:
Intentional tampering with the emissions control system can
result in civil penalties being assessed against you.
Carbon Monoxide Warnings
• An out-of-tune engine or certain fuel or ignitionmalfunctions can cause the catalytic converter to over -
heat. If you notice a pungent burning odor or some
light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact an authorized dealer for service assistance.
• The use of fuel additives, which are now being sold as octane enhancers, is not recommended. Most of these
products contain high concentrations of methanol. Fuel
system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer and may void or
not be covered under the New Vehicle Limited
Warranty. CAUTION!
(Continued)WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
• Do not inhale exhaust gases. They contain carbon monoxide, a colorless and odorless gas, which can kill.
Never run the engine in a closed area, such as a garage,
and never sit in a parked vehicle with the engine
running for an extended period. If the vehicle is
stopped in an open area with the engine running for
more than a short period, adjust the ventilation system
to force fresh, outside air into the vehicle.
• Guard against carbon monoxide with proper mainte -
nance. Have the exhaust system inspected every time
the vehicle is raised. Have any abnormal conditions
repaired promptly. Until repaired, drive with all side
windows fully open.