slick mud. As when you are driving over sand, apply the accelerator
slowly and avoid spinning your wheels. If the vehicle does slide, steer in
the direction of the slide until you regain control of the vehicle.
If the transmission, transfer case or front axle are submerged in water,
their fluids should be checked and changed, if necessary.
Driving through deep water may damage the transmission.
If the front or rear axle is submerged in water, the axle lubricant should
be replaced.
After driving through mud, clean off residue stuck to rotating driveshafts
and tires. Excess mud stuck on tires and rotating driveshafts causes an
imbalance that could damage drive components.
“ Tread Lightly ” is an educational
program designed to increase public
awareness of land-use regulations
and responsibilities in our nations
wilderness areas. Ford Motor
Company joins the U.S. Forest Service and the Bureau of Land
Management in encouraging you to help preserve our national forest and
other public and private lands by “ treading lightly. ”
Driving on hilly or sloping terrain
Although natural obstacles may make it necessary to travel diagonally up
or down a hill or steep incline, you should always try to drive straight up
or straight down. Avoid driving crosswise or turning on steep
slopes or hills . A danger lies in losing traction, slipping sideways and
possibly rolling over. Whenever driving on a hill, determine beforehand
the route you will use. Do not drive over the crest of a hill without
seeing what conditions are on the other side. Do not drive in reverse
over a hill without the aid of an observer.
When climbing a steep slope or hill,
start in a lower gear rather than
downshifting to a lower gear from a
higher gear once the ascent has
started. This reduces strain on the
engine and the possibility of stalling.
If you do stall out, do not try to
turn around because you might roll
over. It is better to back down to a
safe location.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus)Driving
248
Apply just enough power to the wheels to climb the hill. Too much
power will cause the tires to slip, spin or lose traction, resulting in loss of
vehicle control.
Descend a hill in the same gear you
would use to climb up the hill to
avoid excessive brake application
and brake overheating. Do not
descend in neutral; instead,
disengage overdrive or manually
shift to a lower gear. When
descending a steep hill, avoid
sudden hard braking as you could
lose control. When you brake hard,
the front wheels can ’ t turn and if
they aren ’ t turning, you won ’ tbe
able to steer. The front wheels have to be turning in order to steer the
vehicle. Rapid pumping of the brake pedal will help you slow the vehicle
and still maintain steering control.
If your vehicle has anti-lock brakes, apply the brakes steadily. Do not
“ pump ” the brakes.
Driving on snow and ice
Four – wheel drive vehicles have advantages over two – wheel drive
vehicles in snow and ice but can skid like any other vehicle.
Should you start to slide while driving on snowy or icy roads, turn the
steering wheel in the direction of the slide until you regain control.
Avoid sudden applications of power and quick changes of direction on
snow and ice. Apply the accelerator slowly and steadily when starting
from a full stop.
Avoid sudden braking as well. Although a four – wheel drive vehicle may
accelerate better than a two-wheel drive vehicle in snow and ice, it won ’ t
stop any faster, because as in other vehicles, braking occurs at all four
wheels. Do not become overconfident as to road conditions.
Make sure you allow sufficient distance between you and other vehicles
for stopping. Drive slower than usual and consider using one of the lower
gears. In emergency stopping situations, apply the brake forcefully and
steadily. Do not “ pump ” the brakes. Refer to the Brakes section of this
chapter for additional information on the operation of the anti-lock brake
system.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus) Driving
249
Each day before you drive, check
your tires. If one looks lower than
the others, use a tire gauge to check
pressure of all tires, and adjust if
required. Check tire pressure with a
tire gauge every few weeks
(including spare). Safe operation
requires tires that are neither
underinflated nor a vehicle which is
overloaded.
Periodically inspect the tire treads and remove stones, nails, glass or
other objects that may be wedged in the tread grooves. Check for holes
or cuts that may permit air leakage from the tire and make necessary
repairs.
Inspect the tire side walls for cuts, bruises and other damage. If internal
damage to the tire is suspected, have the tire demounted and inspected
to determine whether it needs to be repaired or replaced.
Maintenance and Modifications
The suspension and steering systems on your vehicle have been designed
and tested to provide predictable performance whether loaded or empty
and durable load carrying capability. For this reason, Ford Motor
Company strongly recommends that you do not make modifications such
as adding or removing parts (such as lift kits or stabilizer bars) or by
using replacement parts not equivalent to the original factory equipment.
Any modifications to a vehicle that raise the center of gravity can make
it more likely the vehicle will roll over as a result of a loss of control.
Ford Motor Company recommends that caution be used with any vehicle
equipped with a high load or device (such as ladder racks or pickup box
cover).
Failure to maintain your vehicle properly may void the warranty, increase
your repair cost, reduce vehicle performance and operational capabilities
and adversely affect driver and passenger safety. Frequent inspection of
vehicle chassis components is recommended if the vehicle is subjected to
heavy off-road usage.
DRIVING THROUGH WATER
Do not drive quickly through standing water, especially if the depth is
unknown. Traction or brake capability may be limited and if the ignition
system gets wet, your engine may stall. Water may also enter your
engine ’ s air intake and severely damage your engine.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus) Driving
251
3. Remove the air filter element
from the air filter housing.
4. Install a new air filter element. Be careful not to crimp the filter
element edges between the air filter housing and cover. This could cause
filter damage and allow unmetered air to enter the engine if not properly
seated.
5. Replace the air filter cover and secure the clamp.
6. Replace the air inlet tube and secure the clamp.
INFORMATION ABOUT UNIFORM TIRE QUALITY GRADING
New vehicles are fitted with tires
that have a rating on them called
Tire Quality Grades. The Quality
grades can be found where
applicable on the tire sidewall
between tread shoulder and
maximum section width. For
example:
• Treadwear 200 Traction AA Temperature A
These Tire Quality Grades are determined by standards that the United
States Department of Transportation has set.
Tire Quality Grades apply to new pneumatic tires for use on passenger
cars. They do not apply to deep tread, winter-type snow tires,
space-saver or temporary use spare tires, tires with nominal rim
diameters of 10 to 12 inches or limited production tires as defined in
Title 49 Code of Federal Regulations Part 575.104(c)(2).
U.S. Department of Transportation-Tire quality grades: The U.S.
Department of Transportation requires Ford to give you the following
information about tire grades exactly as the government has written it.
Treadwear
The treadwear grade is a comparative rating based on the wear rate of
the tire when tested under controlled conditions on a specified
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus) Maintenance and Specifications
333
government test course. For example, a tire graded 150 would wear one
and one-half (1 1/2) times as well on the government course as a tire
graded 100. The relative performance of tires depends upon the actual
conditions of their use, however, and may depart significantly from the
norm due to variations in driving habits, service practices, and
differences in road characteristics and climate.
Traction AA A B C
The traction grades, from highest to lowest are AA, A, B, and C. The
grades represent the tire ’ s ability to stop on wet pavement as measured
under controlled conditions on specified government test surfaces of
asphalt and concrete. A tire marked C may have poor traction
performance.
The traction grade assigned to this tire is based on
straight-ahead braking traction tests, and does not include
acceleration, cornering, hydroplaning or peak traction characteristics.
Temperature A B C
The temperature grades are A (the highest), B and C, representing the
tire ’ s resistance to the generation of heat and its ability to dissipate heat
when tested under controlled conditions on a specified indoor laboratory
test wheel. Sustained high temperature can cause the material of the tire
to degenerate and reduce tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to a level of performance
which all passenger car tires must meet under the Federal Motor Vehicle
Safety Standard No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the minimum required by
law.
The temperature grade for this tire is established for a tire that
is properly inflated and not overloaded. Excessive speed,
underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
TIRES
Tires are designed to give many thousands of miles of service, but they
must be maintained in order to get the maximum benefit from them.
Glossary of tire terminology
• Tire label: A label showing the OE (Original Equipment) tire sizes,
recommended inflation pressure and the maximum weight the vehicle
can carry.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus)Maintenance and Specifications
334
12. Treadwear, Traction and Temperature Grades
• Treadwear: The treadwear grade is a comparative rating based on the
wear rate of the tire when tested under controlled conditions on a
specified government test course. For example, a tire graded 150
would wear one and one-half (1 1
2
) times as well on the government
course as a tire graded 100.
• Traction: The traction grades, from highest to lowest are AA, A, B,
and C. The grades represent the tire ’ s ability to stop on wet pavement
as measured under controlled conditions on specified government test
surfaces of asphalt and concrete. A tire marked C may have poor
traction performance.
• Temperature: The temperature grades are A (the highest), B and C,
representing the tire ’ s resistance to the generation of heat and its
ability to dissipate heat when tested under controlled conditions on a
specified indoor laboratory test wheel.
13. Maximum Permissible Inflation Pressure: Tire manufactures
maximum permissible pressure and/or the pressure at which the
maximum load can be carried by the tire. This pressure is normally
higher than the manufacturer ’ s recommended cold inflation pressure
which can be found on either the tire label or certification label which is
located on the structure by the trailing edge of the driver ’ s door or the
edge of the driver ’ s door. The cold inflation pressure should never be set
lower than the recommended pressure on the label.
Note: You may not find this information on all tires because it is not
required by federal law.
The tire suppliers may have additional markings, notes or warnings such
as standard load, radial tubeless, etc.
2004 Navigator (nav)
Owners Guide (post-2002-fmt)
USA English (fus)Maintenance and Specifications
338