Page 529 of 734

WARNING!
Tires and the spare tire should be replaced after six
years, regardless of the remaining tread. Failure to
follow this warning can result in sudden tire failure.
You could lose control and have a collision resulting in
serious injury or death.
Keep dismounted tires in a cool, dry place with as little
exposure to light as possible. Protect tires from contact with
oil, grease, and gasoline.
Replacement Tires
The tires on your new vehicle provide a balance of many
characteristics. They should be inspected regularly for
wear and correct cold tire inflation pressures. The manu-
facturer strongly recommends that you use tires equivalent
to the originals in size, quality and performance when
replacement is needed. Refer to the paragraph on “Tread
Wear Indicator” in this section. Refer to the Tire and
Loading Information placard or the Vehicle Certification
Label for the size designation of your tire. The Load Index
and Speed Symbol for your tire will be found on the
original equipment tire sidewall. See the Tire Sizing Chart example found in the “Tire Safety Information” section of
this manual for more information relating to the Load
Index and Speed Symbol of a tire.
It is recommended to replace the two front tires or two rear
tires as a pair. Replacing just one tire can seriously affect
your vehicle’s handling. If you ever replace a wheel, make
sure that the wheel’s specifications match those of the
original wheels.
It is recommended you contact your authorized tire dealer
or original equipment dealer with any questions you may
have on tire specifications or capability. Failure to use
equivalent replacement tires may adversely affect the
safety, handling, and ride of your vehicle.
5
STARTING AND OPERATING 527
Page 614 of 734

6. Finish tightening the lug nuts. Push down on thewrench while at the end of the handle for increased
leverage. Tighten the lug nuts in a star pattern until each
nut has been tightened twice. For the correct lug nut
torque refer to “Torque Specifications” in this section. If
in doubt about the correct tightness, have them checked
with a torque wrench by you authorized dealer or
service station.
WARNING!
A loose tire or jack thrown forward in a collision or
hard stop could injure someone in the vehicle. Always
stow the jack parts and the extra tire and wheel in the
places provided.
7. Install the wheel center cap and remove the wheel blocks. Do not install chrome or aluminum wheel center
caps on the spare wheel. This may result in cap damage.
8. Lower the jack to its fully closed position. Stow the replaced tire, jack, and tools as previously described.
NOTE: If the bottle jack will not lower by turning the dial
(thumbwheel) by hand, it may be necessary to use the jack
drive tube in order to lower the jack.
9. Adjust the tire pressure when possible.
NOTE: Do not oil wheel studs. For chrome wheels, do not
substitute with chrome plated wheel nuts.
Dual Rear Wheel Placement
612 WHAT TO DO IN EMERGENCIES
Page 642 of 734

CAUTION!(Continued)
have potential malfunctions examined by an autho-
rized dealer or qualified repair center.
• 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, 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 proce-
dure.
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.
Change Engine Oil
The oil change indicator system will remind you that it is
time to take your vehicle in for scheduled maintenance.
Refer to the “Maintenance Schedule” for further informa-
tion.
1500 Models Only
NOTE:
Under no circumstances should oil change inter-
vals exceed 10,000 miles (16,000 km), twelve months or 350
hours of engine run time, whichever comes first. The 350
hours of engine run or idle time is generally only a concern
for fleet customers.
640 MAINTAINING YOUR VEHICLE
Page 707 of 734

Once A Month Or Before A Long Trip:
•Check engine oil level
• Check windshield washer fluid level
• Check tire pressure and look for unusual wear or
damage. Rotate tires at the first sign of irregular wear,
even if it occurs before the oil indicator system turns on.
• Check the fluid levels of the coolant reservoir, brake
master cylinder, power steering (2500/3500 Models
Only) and automatic transmission (six-speed only) and
fill as needed
• Check function of all interior and exterior lights
Maintenance Chart
Required Maintenance
Refer to the Maintenance Schedules on the following pages
for required maintenance.
At Every Oil Change Interval As Indicated By Oil
Change Indicator System:
•Change oil and filter.
• Rotate the tires. Rotate at the first sign of irregular
wear, even if it occurs before the oil indicator
system turns on.
• Inspect battery and clean and tighten terminals as
required.
• Inspect automatic transmission fluid if equipped
with dipstick.
• Inspect brake pads, shoes, rotors, drums, hoses and
park brake.
• Inspect engine cooling system protection and hoses.
• Inspect exhaust system.
• Inspect engine air cleaner if using in dusty or
off-road conditions.
• Lube the front drive shaft fitting (2500/3500 (4x4)
models only). 8
MAINTENANCE SCHEDULES 705