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When to Change Lubricant
Refer to the Maintenance Schedule to determine how
often to change the lubricant. SeeScheduled
Maintenance on page 6-5.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. SeePart C: Recommended
Fluids and Lubricants on page 6-31.
Front Axle
When to Check Lubricant
It is not necessary to regularly check front axle fluid
unless you suspect there is a leak or you hear an
unusual noise. A fluid loss could indicate a problem.
Have it inspected and repaired.
Notice:If you drive your vehicle through deep
water that is higher than the front or rear axle, water
may enter the axle housing and cause the axle
lubricant to break down. This could damage the
gears inside. Avoid driving your vehicle through
deep water.You should avoid driving your vehicle through deep
puddles or standing water. If you must drive through
water that is higher than the front or rear axle, see your
dealer immediately afterward to have the condition of
the axle lubricant checked.
How to Check Lubricant
To get an accurate reading, the vehicle should be on a
level surface.
If the level is below the bottom of the filler plug hole,
you may need to add some lubricant.
Add enough lubricant to raise the level to the bottom of
the filler plug hole.
5-74
Page 288 of 384

Dual Tire Operation
When the vehicle is new, check the wheel nut tightness
on all wheels with a torque wrench after your first
100 miles (160 km) and then 1,000 miles (1 600 km)
after that. Whenever a wheel, wheel bolt or wheel nut is
removed or serviced, repeat the 100 miles (160 km),
and then 1,000 mile (1 600 km) wheel nut tightness
check.
SeeTightening the Wheel Nuts on page 5-86for wheel
nut tightening information and proper torque values.
{CAUTION:
If you operate your vehicle with a tire that is
badly underin ated, the tire can overheat. An
overheated tire can lose air suddenly or catch
re. You or others could be injured. Be sure all
tires (including the spare, if any) are properly
in ated.
SeeTires on page 5-82andInflation - Tire Pressure on
page 5-82for more information on proper tire inflation.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
influence when you need new tires.
Replace your tires when the tread depth is down to
1/8 of an inch (3.2 mm) for the front tires, or 1/16 of an
inch (1.6 mm) for a rear tire. Also, you need a new
tire if:
•You can see cord or fabric showing through the
tire’s rubber.
•The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
•The tire has a bump, bulge, or split.
•The tire has a puncture, cut, or other damage that
cannot be repaired well because of the size or
location of the damage.
The rubber in tires degrades over time, even if they are
not being used. This is also true for the spare tire, if
your vehicle has one. Multiple conditions affect how fast
this aging takes place, including temperatures, loading
conditions, and inflation pressure maintenance. With
proper care and maintenance tires will typically wear out
before they degrade due to age. If you are unsure about
the need to replace your tires as they get older, consult
the tire manufacturer for more information.
5-84
Page 304 of 384

Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, floor pan,
and exhaust system even though they have corrosion
protection.
At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of
the frame should be loosened before being flushed.
Your dealer/retailer or an underbody car washing system
can do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on the vehicle. This damage can
take two forms: blotchy, ring-shaped discolorations,
and small, irregular dark spots etched into the paint
surface.
Although no defect in the paint job causes this, we will
repair, at no charge to the owner, the surfaces of new
vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs first.
Vehicle Care/Appearance Materials
Description Usage
Polishing Cloth
Wax-TreatedInterior and exterior
polishing cloth.
Tar and Road Oil
RemoverRemoves tar, road oil and
asphalt.
Chrome Cleaner and
PolishUse on chrome or
stainless steel.
White Sidewall Tire
CleanerRemoves soil and black
marks from whitewalls.
Vinyl Cleaner Cleans vinyl.
Glass CleanerRemoves dirt, grime,
smoke and fingerprints.
Chrome and Wire Wheel
CleanerRemoves dirt and grime
from chrome wheels and
wire wheel covers.
Finish EnhancerRemoves dust,
fingerprints, and surface
contaminants. Spray on
wipe off.
Swirl Remover PolishRemoves swirl marks,
fine scratches and other
light surface
contamination.
5-100
Page 308 of 384
Fuse Usage
1 Stoplamps
2 Not Used
3 Parking Lamps
4 Powertrain Control Module
5 Auxiliary Wiring
6 Heater/Air ConditioningFuse Usage
7 Hazard Warning Flashers
8 Power Post
9 Courtesy Lamps
10Warning Lights, Gages and
Indicators
11 Starter
12 Rear Axle/Four-Wheel-Drive
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Fuse Usage
RR DEFOG Rear Defogger
ENG 1 Engine 1
ENG 3 Engine 3 (L18/LF6/LF8)
PCM-B Powertrain Control Module
TCM Transmissions (LF8)
ENG 4 Engine 4 (LMM/LF6/LF8)
ENG 2 Engine 2 (L18/LMM)
HTD FUEL Heated Fuel (LMM)
BLANK Not Used
BLANK Not Used
NOTE 3 Fan Relay (LMM), Emissions (L18)
A/C COMP Air Conditioning Compressor
ABS 1 Antilock Brake System 1
ABS 2 Antilock Brake System 2
ABS 3 Antilock Brake System 3
ENGINE Engine
E/A PUMP Electronic/Automatic Pump
HORN HornFuse Usage
NOTE 2Fuel (L18/LMM), Electronic Control
Module (LF6)
NOTE 4 Electronic Control Module (LF6)
STUD A Spare
STUD B Spare
Relay Usage
NOTE 1 LMM/L18 Fuel Pump Relay
IGN B RELAY Ignition Relay
STARTER
RELAYStarter Relay
HORN RELAY Horn Relay
IGN A RELAY Ignition Relay
PTO/ECU*
RELAYPower Take-Off/Engine Control Unit
(*Diesel 7.8L LF8)
REVERSE
RELAYReverse Relay
FAN RELAY Fan Relay (LMM)
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