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6-12
Engine:
Removal or rendering engine speed governor
(if equipped) inoperative so as to allow engine speed
to exceed manufacturer specifications.
Fan and Drive:
Removal of fan clutch (if equipped) or rendering
clutch inoperative.
Removal of the fan shroud (if equipped).
Air Intake:
Removal of the air cleaner silencer.
Reversing the air cleaner cover.
Exhaust:
Removal of the muffler and/or resonator.
Removal of the exhaust pipes and exhaust
pipe clamps.Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see ªEngine Oil
(Diesel Engine)º in the Diesel Engine Supplement.
Checking Engine Oil
It's a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil must
be warm and the vehicle must be on level ground.
The engine oil dipstick has
a yellow handle and is
located near the center of
the engine compartment.
See ªEngine Compartment Overviewº in the Index for
more information on location.
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6-13
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you don't, the oil dipstick
might not show the actual level.
Pull out the dipstick and clean it with a paper towel or
cloth, then push it back in all the way. Remove it again,
keeping the tip down, and check the level.
When to Add Engine Oil
If the oil is at or below the ADD mark, then you'll need
to add at least one quart of oil. But you must use the
right kind. This part explains what kind of oil to use. For
crankcase capacity, see ªCapacities and Specificationsº
in the Index.
NOTICE:
Don't add too much oil. If your engine has so
much oil that the oil level gets above the upper
mark that shows the proper operating range,
your engine could be damaged.
The engine oil filler cap
is located between the
coolant recovery tank and
the engine air cleaner/filter.
See ªEngine Compartment
Overviewº in the Index
for more information
on location.
Be sure to fill it enough to put the level somewhere in
the proper operating range. Push the dipstick all the way
back in when you're through.
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6-16
If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months
-- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions causes engine oil to
break down slower.
What to Do with Used Oil
Did you know that used engine oil contains certain
elements that may be unhealthy for your skin and could
even cause cancer? Don't let used oil stay on your skin
for very long. Clean your skin and nails with soap and
water, or a good hand cleaner. Wash or properly throw
away clothing or rags containing used engine oil. See
the manufacturer's warnings about the use and disposal
of oil products.
Used oil can be a real threat to the environment. If you
change your own oil, be sure to drain all free
-flowing oil
from the filter before disposal. Don't ever dispose of oil
by putting it in the trash, pouring it on the ground, into
sewers, or into streams or bodies of water. Instead,
recycle it by taking it to a place that collects used oil. If
you have a problem properly disposing of your used oil,
ask your dealer, a service station or a local recycling
center for help.
Engine Air Cleaner/Filter
(Gasoline Engines)
The engine air cleaner/filter
assembly has an indicator
that lets you know when the
air filter is dirty and needs
to be serviced. See ªOwner
Checks and Servicesº in the
Index to determine when to
check the indicator.
If the area inside the clear section of the indicator is
green, no air filter service is required. When the area
inside the indicator is orange and CHANGE AIR
FILTER appears, the filter should be replaced.
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6-18
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can
cause a damaging engine fire. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/filter in place when
you're driving.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see ªAutomatic
Transmission Fluidº in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 50,000 miles
(83 000 km) if the vehicle's GVWR is over 8,600 or
if the vehicle is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches 90F (32C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery service.
If your vehicle's GVWR is not over 8,600 and you do not
use your vehicle under any of these conditions, change the
fluid and filter every 100,000 miles (166 000 km).
See ªScheduled Maintenance Servicesº in the Index.
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6-22
Rear Axle
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it.
See ªScheduled Maintenance Servicesº in the Index.
How to Check Lubricant
If the level is below the
bottom of the filler plug
hole, you'll need to add
some lubricant. Add enough
lubricant to raise the level
to the bottom of the filler
plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see ªEngine Overheatingº in
the Index.
A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:
Give freezing protection down to
-34F (-37C).
Give boiling protection up to 265F (129C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
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6-69 Crankcase Capacity
ENGINE VIN Quantity With Filter
ªVORTECº 4300 V6 W 4.5 quarts (4.3 L)
ªVORTECº 5000 V8 M 5.0 quarts (4.8 L)
ªVORTECº 5700 V8 R 5.0 quarts (4.8 L)
ªVORTECº 8100 V8 G 6.5 quarts (6.15 L)
After refill, the level MUST be rechecked. Add enough engine oil so that the fluid is within the proper operating
range. Variation in oil filter size and oil cooler drainback can cause different fill levels. See ªEngine Oilº in the Index.
Fuel Tank Capacity
TYPE QUANTITY MODEL TYPE
Standard Tank 31.0 U.S. gallons (117.3 L) Passenger and Cargo
Standard Tank 35.0 U.S. gallons (132.5 L) Cab and Chassis
Optional Tank* 55.0 U.S. gallons (208.1 L) Cab and Chassis
*159 inch wheelbase or 177 inch wheelbase
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Scheduled Maintenance
7-5
Short Trip/City Definition
Follow the Short Trip/City Scheduled Maintenance if
any one of these conditions is true for your vehicle:
Most trips are less than 5 to 10 miles (8 to 16 km).
This is particularly important when outside
temperatures are below freezing.
Most trips include extensive idling (such as frequent
driving in stop
-and-go traffic).
Most trips are through dusty areas.
You frequently tow a trailer or use a carrier on top of
your vehicle.
If the vehicle is used for delivery service, police, taxi
or other commercial application.
One of the reasons you should follow this schedule
if you operate your vehicle under any of these
conditions is that these conditions cause engine oil to
break down sooner.
Short Trip/City Intervals
Every 3,000 Miles (5 000 km): Engine Oil and
Filter Change (or 3 months, whichever occurs first).
Chassis Lubrication (or 3 months, whichever occurs
first). Drive Axle Service (or 3 months, whichever
occurs first).
Every 6,000 Miles (10 000 km): Tire Rotation.
Every 15,000 Miles (25 000 km): Diesel Engine Only:
Engine Air Cleaner Filter Inspection, if driving in
dusty conditions. Gasoline Engine Only: Noise
Shields Inspection (GVWR above 10,000 lbs. only).
Diesel Engine Only: Shields and Underhood
Insulation Inspection. Diesel Engine Only:
Thermostatically Controlled Engine Cooling Fan
Check (or every 12 months, whichever occurs first).
Diesel Engine Only: Air Intake System Inspection.
Front Wheel Bearing Repack (or at each brake
relining, whichever occurs first).
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Scheduled Maintenance
7-7
Long Trip/Highway Definition
Follow this scheduled maintenance only if none of the
conditions from the Short Trip/City Scheduled
Maintenance are true. Do not use this schedule if the
vehicle is used for trailer towing, driven in a dusty area
or used off paved roads. Use the Short Trip/City
schedule for these conditions.
Driving a vehicle with a fully warmed engine
under highway conditions causes engine oil to
break down slower.
Long Trip/Highway Intervals
Every 7,500 Miles (12 500 km): Engine Oil and Filter
Change (or every 12 months, whichever occurs first).
Chassis Lubrication (or every 12 months, whichever
occurs first). Drive Axle Service. Tire Rotation.
Every 15,000 Miles (25 000 km): Gasoline Engine
Only: Noise Shields Inspection (GVWR above
10,000 lbs. only). Diesel Engine Only: Shields and
Underhood Insulation Inspection. Diesel Engine
Only: Thermostatically Controlled Engine
Cooling Fan Check (or every 12 months, whichever
occurs first). Diesel Engine Only: Air Intake
System Inspection.
Every 30,000 Miles (50 000 km): Fuel Filter
Replacement. Diesel Engine Only: Engine Air
Cleaner Filter Replacement. Front Wheel
Bearing Repack (or at each brake relining,
whichever occurs first).