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Normal maintenance
Over a period of time, if not routinely cleaned, a slight film of oil can
collect dirt around the rubber fill plug and face, which could appear to
be a leak. Routine cleaning ensures that the lube level can be easily
observed through the clear window as intended. In situations where the
window is clean on the outside but discolored on the inside, the lube
level may be checked by inserting a finger through the rubber check
vent hole.
The specified lube level for a clear window type hubcaps is from the
minimum line to + 5/16 inch above the minimum line.
If the lube level should suddenly drop dramatically below the minimum
level, see theWorkshop Manualfor diagnostic procedure.
Installation, tightening and alignment
When installing wheels, be certain that the threads on studs and nuts are
clean to permit correct torque. The mounting surfaces of rims, wheels,
spacer rings and clamps must be free of dirt, rust, lubricants or damage.
Use a wire brush to clean the mounting contact surfaces. Do not use
lubricant on threads.
After the rim or wheel has been properly tightened, it should be checked
for alignment. Rotate the wheel with a piece of chalk attached to a
steady, firm surface, and placed to just barely clear the outside surface of
the tire bead seat. This procedure will point out the high spot. A high
spot does not necessarily mean that the lug nuts have been unevenly
tightened. This condition or misalignment could be caused by a bent
wheel.
Use the following installation procedure:
1. Slide inner rear or front tire and wheel in position over studs and push
it back as far as possible. Use care so that the threads on studs are not
damaged.
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Disc wheel with flange nuts (hub-piloted)
Front wheel mounting of flange nut
system
1. Flange nut
2. Wheel(s)
3. Brake drum
4. Wheel stud (22 mm)
5. Wheel hub
2. Position the outer rear tire and wheel in place over the studs and
push it back as far as possible. Use care so that the threads on studs are
not damaged.
Rear wheel mounting of flange nut
system
1. Flange nut
2. Wheel(s)
3. Brake drum
4. Wheel stud (22 mm)
5. Wheel hub
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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
Note for aluminum wheels: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.
3. Run the nuts on the studs until they contact the wheel(s). Rotate the
wheel assembly a half-turn to permit the parts to seat.
4. Draw up the nuts alternately following the crisscross sequence
illustrated under the following wheel tightening sequence illustrations.
Do not fully tighten the nuts. This will allow uniform seating of the nuts
and ensure even face-to-face contact of the wheel and hub.
1
6
5
4
32
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Wheel tightening sequence:
8–lug wheel
10–lug wheel
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 50 miles (80 km), 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.
Note: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.
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.
Changing wheel types
Consult your dealer or wheel/rim distributor before attempting any wheel
or fastener changes.
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WARNING: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.
Note:Do not attempt to mix stud-piloted wheels or fasteners with
hub-piloted wheels or fasteners.
Note: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
ft-lb N•m
22 mm Flange 450–500 610–678
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.
TIRE INFORMATION
Inflation
WARNING:Always maintain your tires in good condition.
Frequently check and maintain correct inflation pressures as
specified by tire manufacturers. Inspect periodically for abnormal wear
patterns and repair/replace cut or broken tire casing. Always use
experienced, trained personnel with proper equipment and correct
procedures to mount or remove tires and wheels. Failure to adhere to
these warnings could result in wheel or tire malfunction, damage to
your vehicle, personal injury, or death.
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WARNING:To avoid personal injury or death, always follow
these instructions when mounting radial tires on wheels:
•Only personnel that have had proper training and experience should
mount or remove tires from rims or wheels.
•Use only heavy-duty rims or approved rims for radial tires. It may be
necessary to contact your wheel and rim distributor to determine if
your rims are approved for radial tires.
•If a tube is to be used, make sure special radial tire tubes are used
because of the increased flexing of the sidewalls on radial tires.
•Never use anti-freeze, silicones, or petroleum based lubricants when
mounting radial tires. Only an approved lubricant should be used as
an aid for mounting tires.
•Always inflate tires in a safety cage.
•Do not attempt to mix stud piloted wheels or fasteners with hub
piloted wheels or fasteners. To do so may cause premature wheel
failure resulting in property damage, personal injury, or death.
•Do not mix foreign (not made in North America) wheel mounting
parts with domestic (made in North America) parts. Many foreign
wheel components look similar to, but not exactly the same as
domestic made components. Mixing components could cause wheel
or fastener failures and result in property damage, personal injury, or
death.
•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.
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 ensure that all persons are clear of
the trajectory area.
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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.
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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 insure 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 will equal
1 2steer axle loading;
each drive tire load will be1 4the axle loading if fitted with four tires).
Checking inflation
Always check inflation pressure when tires are cold. Never bleed air from
hot tires to relieve normal pressure build-up. Normal increases in
pressure due to service conditions will be 10–15 psi (69–103 kPa), which
is allowable in truck tires.
Tires should be properly inflated to manufacturers recommended
pressure for the size and service load in which the vehicle is being used.
Refer to the specific tire manufacturer with which your vehicle is
equipped with for the latest information concerning service load and
inflation pressure.
It is particularly important to keep moisture from the inside of tires, and
proper selection of air compressor equipment, proper air line routing,
and the use of shop air dryers is strongly recommended to avoid
moisture in the high pressure air used for tire inflation.
Under-inflation
Tires should not be permitted to become under-inflated. Increased
flexing due to under-inflation causes heat build-up within the tire
components. This leads to reduced strength, breakdown of the rubber
compounds, and possible separation of the tire components (i.e., ply and
tread separation and reduced retreadability).
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