STEERING
To help prevent damage to the power
steering system:
•
Never hold the steering wheel at its
furthest turning points (until it stops)
for more than three to five seconds
when the engine is running.
• Do not operate the vehicle with a low
power steering pump fluid level (below
the MIN mark on the reservoir).
• Some noise is normal during operation.
If excessive, check for low power
steering pump fluid level before
seeking service by your dealer.
• Heavy or uneven efforts may be caused
by low power steering fluid. Check for
low power steering pump fluid level
before seeking service by your dealer.
• Do not fill the power steering pump
reservoir above the MAX mark on the
reservoir, as this may result in leaks
from the reservoir.
If the power steering system breaks down
(or if the engine is turned off), you can
steer the vehicle manually, but it takes
more effort.
Operating the steering system excessively
at an elevated engine RPM (>1200 rpm)
for more than 2 minutes can result in
steering system damage from overheating.
Move the steering wheel to the full left
position then full right position at idle
speed, or stop using the system for 2
minutes to allow the system to cool down.
If the power steering system exhibits heavy
or uneven efforts, check for the following
before seeking service from your dealer:
• An improperly inflated tire.
• Overloading of front suspension.
• Uneven vehicle loading.
• Binding suspension components. If the power steering system wanders or
pulls, check for:
•
An improperly inflated tire.
• Uneven vehicle loading.
• Uneven tire wear.
• Loose or worn suspension
components.
• Loose or worn steering components.
• Improper vehicle alignment.
• High crosswinds.
If any steering components are serviced or
replaced, install new fasteners (many are
coated with thread adhesive or have
prevailing torque features which may not
be re-used). Never re-use a bolt or nut.
Torque fasteners to specifications.
A high crown in the road or high crosswinds
may also make the steering seem to
wander or pull.
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Parking
WARNING
When parking your vehicle, do not
leave the transmission in gear; if the
key is in the on position and the
vehicle rolls, the engine could start. Failure
to follow these instructions could result in
an unattended vehicle moving, possibly
causing personal injury or property
damage. Always use the parking brake. When
parking on a grade, block the wheels and
turn the front wheels to one side so that if
your vehicle rolls, the front tires act against
the curb to stop your vehicle. The front
wheels are more effective at stopping a
rolling vehicle than the rear wheels.
ECONOMICAL DRIVING
Your fuel economy is affected by several
things, such as how you drive, the
conditions you drive under, and how you
maintain your vehicle.
You may improve your fuel economy by
keeping these things in mind:
•
Accelerate and slow down in a smooth,
moderate fashion.
• Drive at steady speeds without
stopping.
• Anticipate stops; slowing down may
eliminate the need to stop.
• Close the windows for high-speed
driving.
• Drive at reasonable speeds (traveling
at 55 mph [88 km/h] uses 15% less
fuel than traveling at 65 mph [105
km/h]).
• Keep the tires properly inflated and use
only the recommended size. •
Use the recommended engine oil.
• Perform all regularly scheduled
maintenance.
Avoid these actions; they reduce your fuel
economy:
• Sudden accelerations or hard
accelerations.
• Warm up your vehicle on cold
mornings.
• Use the air conditioner or front
defroster.
• Use the speed control in hilly terrain.
• Rest your foot on the brake pedal while
driving.
• Carry unnecessary weight
(approximately 1 mpg [0.4 km/L] is
lost for every 400 lb [180 kilogram] of
weight carried).
• Driving with the wheels out of
alignment.
Conditions
• Adding certain accessories to your
vehicle (for example bug deflectors,
rollbars, light bars, running boards, ski
racks or luggage racks) may reduce
fuel economy.
• Using fuel blended with alcohol may
lower fuel economy.
• Fuel economy may decrease with lower
temperatures during the first 8– 10
miles (12 –16 kilometers) of driving.
• Driving on flat terrain offers improved
fuel economy as compared to driving
on hilly terrain.
• Transmissions give their best fuel
economy when operated in the top
cruise gear and with steady pressure
on the gas pedal.
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F-650/750 (TBC) , enUSA, First Printing Driving Hints
AXLE INSPECTION
Front Axle
Maintaining the front axle alignment to
specifications is very important. A qualified
technician should check and maintain the
alignment.
Regular inspections should include:
•
Toe-in inspection and adjustment (if
necessary), particularly with radial
tires.
• Checking for proper tightness of axle
mounting U-bolt nuts, attaching or
mounting bolts and nuts.
• Checking the axle for damage, binding,
worn parts and adequate lubrication.
• Checking the kingpins for excessive
wear. Also, perform this check during
other scheduled maintenance, for
example as tire rotation or service,
wheel bearing service and alignment.
See the workshop manual for proper
procedures.
Toe-in
It is essential to maintain correct toe-in
and tire pressure for optimum tire wear.
Inspecting steer axle tires in the first
3,000– 10,000 mi (5,000– 16,000 km)
generally shows if tires are wearing
normally.
Rapid outside shoulder wear on both tires
indicates too much toe-in.
Rapid inside shoulder wear on both tires
indicates too much toe-out.
In P&D-type service, there can be a
left-to-right steer tire tread life differential
up to 40% depending on routes and other
variables. Follow the tire manufacturer's
recommended cold inflation pressure for
the tire size, load range (ply rating) and
steer axle loading typical for their operation
(each steer axle tire equals ½ steer axle
loading).
Special applications may warrant a setting
based on experience with the type of tire
operating loads and conditions. Radial tires
are more sensitive to toe-in setting than
bias ply tires. Fine tuning school bus
alignment to line-haul truck standards
does not drastically improve tire tread life.
STEERING SYSTEM
INSPECTION
WARNING
Failure to maintain the steering
system in proper condition can cause
reduced steering ability resulting in
property damage, personal injury or death. Note:
Have any steering problems
immediately corrected by a qualified service
technician.
Ask your service technician to examine the
steering mechanism. Only minor
adjustments may be necessary.
Regular inspections should include:
• Checking the tie rod, drag link end
clamp bolts and ball joints for proper
tightness.
• Checking for installation and spread of
cotter pins and tightness of nuts at
both ends of the tie rod and drag link.
• Checking that the pitman arm (steering
arm at steering gear) mounting is tight
and locked. Check system for leaks or
hose chafing. Repair immediately, if
necessary.
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*Do not run over curbs or hit the
tire against a curb when parking
Highway Hazards
No matter how carefully you drive
there
’s always the possibility that
you may eventually have a flat tire
on the highway. Drive slowly to the
closest safe area out of traffic.
This may further damage the flat
tire, but your safety is more
important.
If you feel a sudden vibration or
ride disturbance while driving, or
you suspect your tire or vehicle
has been damaged, immediately
reduce your speed. Drive with
caution until you can safely pull
off the road. Stop and inspect the
tires for damage. If a tire is
under-inflated or damaged,
deflate it, remove wheel and
replace it with your spare tire and
wheel. If you cannot detect a
cause, have the vehicle towed to
the nearest repair facility or tire
dealer to have the vehicle
inspected.
Tire and Wheel Alignment
A bad jolt from hitting a curb or
pothole can cause the front end
of your vehicle to become
misaligned or cause damage to
your tires. If your vehicle seems to
pull to one side when you’re
driving, the wheels may be out of
alignment. Have an authorized
dealer check the wheel alignment
periodically. Wheel misalignment in the front
or the rear can cause uneven and
rapid treadwear of your tires and
should be corrected by an
authorized dealer. Front-wheel
drive vehicles and those with an
independent rear suspension may
require alignment of all four
wheels.
The tires should also be balanced
periodically. An unbalanced tire
and wheel assembly may result in
irregular tire wear.
Tire Rotation
Note:
If your tires show uneven
wear ask an authorized dealer to
check for and correct any wheel
misalignment, tire imbalance or
mechanical problem involved
before tire rotation.
Note: Your vehicle may be
equipped with a dissimilar spare
wheel and tire assembly. A
dissimilar spare wheel and tire
assembly is defined as a spare
wheel and tire assembly that is
different in brand, size or
appearance from the road tires and
wheels. If you have a dissimilar
spare wheel and tire assembly it is
intended for temporary use only
and should not be used in a tire
rotation.
Rotating your tires at the
recommended interval will help
your tires wear more evenly,
providing better tire performance
and longer tire life.
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