wheel torque FORD F650 2004 11.G Owners Manual

Releasing spring brake with air pressure
The air system in all vehicles with spring-actuated rear wheel parking
brakes is equipped with a tank valve located on the supply or service air
tank for connection to an outside air supply. The valve permits the
system to be recharged with air from an outside source, releasing the
spring-actuated parking brakes. The vehicle may then be towed in an
emergency.
An outside air source can be used only if the protected system is in
operating condition. If air pressure cannot be restored in the protected
air system, the spring-actuated brakes must be released manually.
Releasing spring brake manually
Do not attempt to disassemble the parking brake chamber under
any circumstances. The high spring load may cause serious
injury if the chamber clamps are removed.
If air pressure is released from the spring brake chamber the power
spring applies the brake and, unless air pressure can be re-established,
the spring brake must be released as follows in order to move the
vehicle.
Block the wheels to prevent the vehicle from moving.
Unexpected and possibly sudden vehicle movement may occur if
these precautions are not taken.
Impact wrenches should not be used as they may damage the piston and
prevent proper caging of the spring. Do not apply more than 68 Nm (50
lb-ft) torque to the release bolt nut.
1. Remove the stud tool and nut
from the carrying pocket on the
brake chamber assembly.
2. Remove the access plug from the
end of the spring chamber.
3. Insert the release stud through
the opening in the chamber and into
the spring pressure plate.
2004 F650/750(f67)
Supplement
USA English(fus)
Driving
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Power take-off (PTO) operation with an Allison automatic
transmission (MD applications)
The PTO drive gear is engine driven and provides direct engine power.
The PTO can be operated when the vehicle is either stationary or
moving.
The PTO gear is in constant mesh with the drive gear in the torque
converter housing. A friction clutch or constant drive is used to transmit
power to the PTO.
CLUTCH (IF EQUIPPED)
Properly maintain the clutch to prolong it’s life. Do not ride or slip the
clutch as this will cause unnecessary heat and wear.
Clutch precautions
Maintain specified clutch adjustment; regularly inspect the clutch control
linkage for tightness.
When adjustment of the clutch is necessary, it is very important that the
work be performed properly or early clutch failure may result and a
costly clutch overhaul may become necessary. Clutch work should only
be performed by a qualified technician.
Engaging the clutch
•Always start in the proper gear.An empty vehicle can start in a
higher gear than a fully loaded vehicle. Starting in too high a gear can
cause clutch slippage and excessive heat and wear on the clutch. A
gear that will start the vehicle moving at idle speed is the correct gear.
If the engine has to be revved to get the vehicle going, the gear
selection is too high.
•Do not shift until the vehicle has reached the proper speed.
Upshifting before the vehicle has reached the proper speed can cause
clutch slippage and excessive heat and wear on the clutch.
•Never hold a vehicle on a grade with the clutch.This will cause
the clutch to slip and can actually burn up the clutch.
•Never coast with the clutch disengaged.The high RPM
(sometimes over 10,000), can actually burst the facing material of the
clutch.
•Never engage the clutch while coasting.Re-engaging the clutch
after coasting may not only cause a great shock to the clutch, but the
whole drivetrain. Internal engine damage and/or clutch and flywheel
failure can result from this.
2004 F650/750(f67)
Supplement
USA English(fus)
Driving
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Installing the axle shafts
1. Remove the covers from the wheel ends
2. Shift the differential lock to the unlocked position (disengaged)
position.
3. Install the axle shafts
•Place the gaskets on the wheel hub studs.
•Push the right-hand axle shaft and gasket in to the wheel end and
housing until the shaft stops against the differential shift collar.
•Push down and in on the axle shaft flange and rotate the shaft until
the splines of the shaft and shift collar are engaged.
•Push the axle shaft further into the housing until the shaft stops
against the differential side gear.
•Push down on the axle shaft flange and rotate the shaft until the
splines of the shaft and side gear are engaged.
•Push the axle shaft completely into the housing until the axle shaft
flange and the gasket are flush against the wheel hub.
•Install the left-hand axle shaft and gasket into the wheel end.
4. If tapered dowels are required, install them at each stud and into the
flange of the axle shaft. Use a punch or drift and hammer, if needed.
5. Install the fasteners and tighten to correct torque value. Refer to the
Service Manual section.
Towing the vehicle with the rear wheels suspended
Note:To avoid damage to the cab roof or air deflector when towing the
vehicle backward (rear wheels suspended) the air deflector must be
removed.
Whenever possible, it is preferable to tow a disabled vehicle from the
rear by raising the rear of the chassis. When towing a vehicle with the
rear of the chassis suspended the front wheels must be locked in the
straight-ahead position.
Vehicles equipped with a manual-shift transmission must have at least
one (1) pint of transmission fluid drained from the case. This will
prevent the transmission fluid from entering the clutch housing and fluid
saturating the clutch discs. Make sure that the transmission fluid is
replaced before the vehicle is returned to service.
2004 F650/750(f67)
Supplement
USA English(fus)
Roadside emergencies
149

Check to make sure that the axle mounting U-bolt nuts, attaching or
mounting bolts and nuts are securely tightened. Regularly check front
axle for damage, binding, worn parts and adequate lubrication.
At regular intervals, or during other scheduled maintenance, (tire
rotation/service, wheel bearing service, alignment, etc.) the kingpins
should be checked for excessive wear. Refer to the service manual for
proper procedures.
Toe-in setting - general inspection
Inspecting steer axle tires in the first 4,800–16,000 service km
(3,000–10,000 service miles) will generally show 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, which includes school buses, left-to-right steer tire
tread life differentials up to 40% can be observed 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 will equal
1⁄2steer axle loading).
Special applications may warrant a setting based on past experience with
the type of tire operating loads and conditions. Radial tires are more
sensitive to toe-in setting than bias ply tires. While not insensitive to
vehicle alignment, fine tuning school bus alignment to line-haul truck
standards will not drastically improve tire tread life.
It is essential that correct toe-in and tire pressure be maintained for
optimum tire wear.
Rear axle - general inspection
Check to make sure that the axle mounting U-bolts, attaching or
mounting bolts and nuts are securely tightened. Refer toU-bolt nut
torque chartin this chapter. Regularly check the rear axle for damaged,
binding or worn parts.
NoSpin Detroit Locker positive locking differential
Vehicle equipped with this type differential have the operator’s manual
supplied with the vehicle. Refer to this manual for maintenance checks.
Brake system - general inspection
Your vehicle is equipped with non-asbestos brake linings. However,
exposure to excessive amounts of brake material (whether asbestos or
2004 F650/750(f67)
Supplement
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Maintenance and specifications
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•Check that torque rod mounting fasteners are tight.
•Check to be sure the suspension alignment is maintained at all time.
•Check U-bolts after the chassis has been operating under load for
1,600 km (1,000 miles) or six months, whichever comes first, the
U-Bolt nuts must be re-torqued. The U-Bolt nuts thereafter must be
re-torqued every 58,000 km (36,000 miles). The U-Bolt and nut
threads and seats should be cleaned and lubricated to assure a“like
new”condition when re-torquing.
Note:See theU-Bolt Nut Torquechart later in this section.
Supporting your vehicle for service
When performing service repairs on your vehicle, first prepare the
vehicle by doing the following:
1. Park the vehicle on a level concrete floor.
2. Set the parking brake and block the wheels to prevent the vehicle
from moving.
3. Select a jack (floor jack preferred) with a rated capacity sufficient to
lift and hold up the vehicle.
4. Raise the vehicle with the jack applied to the axle(s). DO NOT use the
bumper as a lifting point.
5. Support the vehicle with floor stands under the axle(s). If the axle or
the suspension are being serviced, support the vehicle with floor stands
under the frame side-members, preferably between the axles.
Do not use a jack when working under a vehicle. It may give
way, causing the vehicle to fall and result in property damage,
personal injury or death. Always use floor stands to support the
vehicle.
FRAME AND TOW HOOKS
Your vehicles chassis is manufactured with frame rails of either mild
carbon steel, or HSLA steel. Each must be handled in a specific manner
to assure maximum service life. Before attempting frame repair or
modification, consult the service manual or your dealer.
It is important, particularly on vehicles where the tow hooks are used
frequently to inspect the front and rear tow hooks for damage or a loose
mounting.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
196

4. Draw up the nuts alternately following the crisscross sequence
illustrated underInstallation, tightening and alignment. Do not fully
tighten the nuts. This will allow uniform seating of the nuts and assure
even face-to-face contact of the wheel and hub.
5. Continue tightening the nuts to the torque specifications in the torque
chart using the same crisscross sequence shown.
6. After operating the vehicle approximately 80 km (50 miles), check the
nuts for tightness. Some natural seating of parts may be encountered
and the torque on the nuts will drop. Retighten all nuts to specifications.
Once a week, inspect and retighten the wheel stud nuts.
Aluminum rear disc wheel with flange nuts (hub-piloted)
1. Flange nut
2. Wheel(s)
3. Brake drum
4. Wheel stud (22 mm)
5. Wheel hub
6. Wheel locator pad
1
6
5
4
32
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
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Prior to re-installing rear aluminum hub-piloted wheels, clean each wheel
locator pad on the hub from all dirt, rust and foreign material. Apply a
light coat of chassis grease, never-seize or disc brake corrosion control
grease, only to the wheel locator pad.
When installing the tire and rim assembly on disc-brake equipped axles,
make sure the tire valve stem clears the brake caliper. The use of a tire
manufacturer’s stem forming tool is the only acceptable method of
obtaining clearance when necessary.
Note:Always observe the following instructions:
•Always loosen rim clamps before complete removal of nut from stud
(cast spoke wheels). With loosened nuts on stud, strike clamps with a
heavy hammer and be sure each clamp is loose.
•Always deflate tires completely before removing locks or side rings.
•Always inflate tires in a safety cage.
•Never mix rim side rings or lock rings of different types,
manufacturers or sizes.
•Never use cracked, bent or badly rusted parts.
•Never re-inflate flat tires on-vehicle; use the spare tire.
•Never add air until each side ring or lock ring is fully seated.
•Never hammer side ring or lock ring on a partially- or fully-inflated
tire.
Failure to follow these instructions could result in property
damage, personal injury or death
Proper torque
It is important to tighten and maintain wheel and rim mounting nuts to
the proper torque. Loose nuts or over-tightened nuts can lead to
premature wear and possible failure of the wheel and/or mounting
hardware.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
203

Changing wheel types
Consult your dealer or wheel/rim distributor before attempting any wheel
or fastener changes.
Use only the same type and style wheels and mounting hardware
to replace original parts. Failure to do so may result in an
assembly that looks fine, but does not fit together properly. This could
possibly cause wheel or fastener failures which could result in property
damage, personal injury or death.
Do not attempt to mix stud-piloted wheels or fasteners with
hub-piloted wheels or fasteners.
Do not change from aluminum wheels to steel wheels or
vice-versa without changing the mounting hardware required or,
with flange-nut mounting systems, changing the hub and stud
assembly.
WHEEL NUT TORQUE
Size Nut mountingTorque
N.m. ft. lbs.
22 mm Flange 610–678 450–500
Note:Do not use lubrication on dry threads. Where excessive corrosion
exists, a light coat of lubricant on the first three threads of the stud bolt
is permitted. Keep lubricant away from:
•Hex nut and rim clamp contact surfaces.
•Cap nut ball face and ball seat on the disc wheel.
•Flange nut washer surface and flat on the disc wheel.
2004 F650/750(f67)
Supplement
USA English(fus)
Maintenance and specifications
204

Maintenance Operation Frequency - Observation
Check the transmission and
engine mountings (*b)Hard shifting or excessive vibration
Check and adjust transmission
controls (*b)High effort to shift or noisy
transmission
Check fuel pump pressure Insufficient full-throttle power or
backfiring
Clean radiator cap seal. Clean
and inspect the cap surface on
the radiatorWhen the cap does not hold pressure
Check the battery terminals for
corrosionWhenever electrical power supply has
diminished
Tighten the wheel mounting
nuts to the specified torque.
Refer toServicing your
wheels and tiresRequired initially at 800 and 1,600 km
(500 and 1,000 miles). Perform again
at 800 and 1,600 km (500 and 1,000
mile) intervals after each tire
removal/replacement.
*a During maintenance and repair, protect the fuel tube and the hose
assemblies, the power steering lines, and the brake lines from the
external heat, the acids and the abrasion that could damage the lines.
*b Check for (free) linkage action and ensure that (return) spring
force is adequate to maintain pedal free play.
*c Adjust, repair or replace as required with the same or equivalent
parts.
2004 F650/750(f67)
Supplement
USA English(fus)
General maintenance information
233