2015 FORD F750 tire type

You can lock and unlock the differential when your vehicle is moving at a
constant speed of less than 25 mph (40 km/h) and while the wheels are
not slipping. Do not lock the differential when your vehicle is traveling
down steep grades and traction is minimal.
The differential lock and differential lock light automatically disengage at
speeds above 25 mph (40 km/h). The differential lock remains off until
either you restart your vehicle or you turn the differential lock switch off
then back on.
Turn the engine off and raise all drive wheels of the locker differential
axle in order to prevent your vehicle from moving when servicing the
wheels, tires or brakes. Axles equipped with a NoSPIN Detroit Locker
differential deliver power to both wheels even when only one wheel is on
the ground.
WARNING:Failure to raise all drive wheels with this type of
differential could cause the vehicle to move unexpectedly,
resulting in property damage, personal injury or death.
Take care to avoid sudden accelerations when both drive wheels are on a
slippery surface.
WARNING:Sudden accelerations on slippery surfaces could
cause the wheels to spin, the vehicle to turn sideways on a
crowned road surface or in a turn, possibly resulting in loss of vehicle
control and personal injury.
Fluid Temperature
Axle operating temperatures normally do not exceed 100°F (38°C). If
the operating temperature exceeds 230°F (110°C), the rate of axle
lubrication oxidation increases and shortens the life of the lubricant and
seals, requiring axle lubrication changes to become more frequent to
preserve the axle. Do not consistently run extreme pressure (EP)
lubricants above 230°F (110°C).
Axle Conversions
WARNING:When operating a loaded vehicle, the driver must
keep all adjustable axles on the ground at all times, supporting
their share of the vehicle’s load. Failure to do so can overload other
axles, tires, wheels, springs, steering components, brakes and frames,
resulting in early component failure, loss of vehicle control, possible
property damage and personal injury.
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If you install an electrical back up alarm, connect it to the backup lamp
circuit.
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.
Cold Weather
Note:Idling in cold weather does not heat the engine to its normal
operating temperature. Long periods of idling in cold weather can cause
a build-up of heavy deposits of carbon and rust on valve stems causing
them to stick which, in turn, can cause valvetrain damage.
Note:We recommend against using winter fronts, or other air-restrictive
devices mounted in front of the radiator on vehicles with
chassis-mounted charge air coolers, unless extremely cold weather
conditions exist. Airflow restriction can cause high exhaust temperatures,
power loss, excessive fan usage and a reduction in fuel economy. If you
must use a winter front, the device should have a permanent opening of
at least 120 square inches (774 square centimeters) directly in line with
the fan hub.
For best engine operation in temperatures of 32°F (0°C) or lower:
•Make sure the batteries are the correct type and are fully charged.
Check other electrical components to make sure they are in optimum
condition.
•Use a permanent-type engine coolant to protect the engine against
damage from freezing.
•If your vehicle is equipped with a water-fuel separator, drain it daily.
Fill the fuel tank at the end of daily operation to prevent
condensation in the fuel system.
•Use the proper engine oil and maintain it at its proper level.
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Climate Control System
Have the air conditioning system checked each spring. The refrigerant
charge, cleanliness of the condenser-evaporator cores and belt condition
are essential to system performance.
When the air conditioning system is being used daily, remove the fresh
air filter (if equipped) once each season and check for things such as
dirt and lint. Replace the filter if necessary. Vehicles operating in
unusually dusty conditions may require more frequent filter inspection
and replacement.
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 (such 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 3000–10000 service miles
(5000–16000 service kilometers) 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
12steer axle loading).
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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.
Rear Axle
Regular inspections should include:
•Checking for proper tightness of axle mounting U-bolt nuts, attaching
or mounting bolts and nuts. SeeSpring U-bolt checkslater in this
chapter.
•Checking the axle for damage, binding, worn parts and adequate
lubrication.
NoSpin Detroit Locker Positive Locking Differential
Vehicles equipped with this type differential have the operator’s manual
supplied with the vehicle. See that manual for maintenance inspections.
Brake System
Note:People handling brake linings should follow all precautions listed
below:
200Maintenance
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Inspection and adjustment:Establish a regular schedule for periodic
cleaning, lubrication and adjustment inspection based on vehicle use.
Exact maintenance intervals are difficult to predetermine due to vehicle
applications and operating conditions. If you are uncertain of the proper
schedule for your vehicle, contact an authorized dealer.
Regular inspections should include:
•Periodic checking (every service interval) of push rod travel or brake
adjustment. This is essential for effective braking. Brake chamber
push rods on original equipment chambers now incorporate an orange
paint marker near the base of the push rod as a stroke indicator to
aid in adjustment checks. If the push rod is clean and the brakes are
out of adjustment, you can see the orange marker protruding from
the chamber when the brakes are applied.
•Checking the brake lining (every service interval). When brake lining
or blocks wear within 1/16th inch (1.6 millimeters) of rivets, replace
the brake linings. A qualified technician should perform this
inspection and keep to instructions provided by the service manual.
Do not back off or disconnect the front brakes so that they are less
effective, letting the rear brakes do all the stopping of your vehicle. Do
not overlook the brakes on the trailer either. Brake condition on the
trailer is just as important as the tractor. Proper brake balance on trucks
and tractor-trailers is essential for effective braking.
Once a year, inspect the entire brake system:
•Rubber components for deterioration. A qualified technician should
inspect these components and replace them as necessary.
Replacement intervals vary according to the severity and length of
vehicle service.
•Condition of brake drums, brake chambers and slack adjusters.
•System for air leaks.
•Hose or pipes for rust, damage and deterioration.
•Operation of service and parking brakes.
Periodically inspect parts such as air brake chamber diaphragm, air
compressor and air cleaner. Replace any parts if you can consider them
unserviceable.
Air dryer:Climactic conditions affect performance of desiccant or
after-cooler type air dryers. You must establish a maintenance schedule
for each specific operation.
The use of an air dryer on a vehicle does not eliminate the need to drain
the air reservoirs periodically.
202Maintenance
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
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WARNING(Continued)
•Do not change from aluminum wheels to steel wheels or vice-versa
without changing the mounting hardware where required or, in some
cases with flange nut mounting systems, changing the hub and stud
assembly. Mixing components could cause wheel or fastener failures
and result in property damage, personal injury, or death.
WARNING:An inflated tire and rim can be very dangerous if
improperly used, serviced or maintained. To avoid serious injury,
never attempt to re-inflate a tire which has been run flat or seriously
under-inflated without first removing the tire from the wheel assembly
for inspection. Do not attempt to add air to tires or replace tires or
wheels without first taking precautions to protect persons and property.
All tires with Steel Carcass Plies (if equipped):This type of tire
utilizes steel cords in the sidewalls. As such, they cannot be treated like
normal light truck tires. Tire service, including adjusting the air pressure,
must be performed by personnel trained, supervised and equipped
according to Federal Occupational Safety and Health Administration
(OSHA) regulations. For example, during any procedure involving tire
inflation, the technician or individual must utilize a remote inflation
device, and make sure that all persons are clear of the trajectory area.
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2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
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Stay out of the trajectory (1) as indicated in the illustration.
WARNING:Do not mount tube type tires on tubeless wheels or
tubeless tires on tube type wheels. To do so could result in tire
or wheel failure and cause property damage, personal injury or death.
Preserving proper inflation pressure is a very important maintenance
practice to make sure safe vehicle operation and long life for the tires.
Failure to maintain correct inflation pressure may result in sudden tire
destruction, improper vehicle handling, and may cause rapid and
irregular tire wear. Therefore, inflation pressures should be checked daily
and always before long distance trips.
Follow the tire manufacturer’s recommended cold inflation pressure for
the tire size, type, load range (ply rating) and axle loading typical for
your operation. (Each steer axle tire load equals one-half steer axle
loading; each drive tire load is one-quarter the axle-loading if fitted with
four tires).
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Rotation may not advisable:
•Front (Steering) Axle:Remove tires when tread wears down to
four–thirty seconds inch (3 millimeters) or less. Retread or rotate
worn tires to drive position. We do not recommend using retreaded
tires on steering axles.
•Rear Axles:Remove tires when tread wears down to two–thirty
seconds inch (2 millimeters).
If using a rib tire on front axle and lug or off-road type on rear axle
positions:
•Front (Steering) Axle:Replace tires at front wheels when tread is
worn to four–thirty seconds inch (3 millimeters) or less.
•Rear Axles:Remove tires when the tread wears down to two–thirty
seconds inch (2 millimeters) or less. Tires identified with the word
re-groovable molded on the sidewall can be re-grooved. There must
be a minimum of three–thirty seconds inch (2.5 millimeters) of
under-tread at the bottom of the grooves.
Wheel and Tire Balancing
Out-of-round or out-of-balance wheels or tires can cause vehicle
vibration, bounce and shimmy. Replace damaged or out-of-round wheels.
You can correct out-of-round tires and wheel assemblies by re-clocking
the tire relative to the wheel.
You should then dynamically balance the tire and wheel assembly.
Tire Wear
Radial tires can exhibit three types of normal wear patterns:
•Even
•Erosion
•Chamfer
Even wear:A sign that the tire is being properly used and maintained.
Erosion wear:Also called rolling wear, channel or river wear, erosion
wear occurs more often on free-rolling tires. This is an indication of
using the tire in a slow wearing operation. What happens is that the belt
plies are held very rigid and the tread is not allowed to distort as it
passes through the contact area. Wear only occurs at the edge of the
tread. No corrective action required. If erosion gets to be one–sixteenth
inch (2 millimeters) or more, you can rotate the tire to a drive axle.
Chamfer or shoulder wear:With tires inflated properly, this is a
normal tendency of most radial tire designs. If both inside and outside
shoulders are wearing evenly around the tire, no further action is
required. Over-inflation is not effective in correcting this effect.
248Wheels and Tires
2015 F-650/750(f67)
Owners Guide gf(ownloose), 1st Printing, December 2013
Canadian_French(fr_can)