Operation and maintenance manual

SM 1382 Rev 1 03-05
Section 160-0050
9
TYRE CARE
To obtain maximum service from off-highway tyres,
the following common-sense precautions should be
followed.
Maintain Correct Inflation
The most common cause of tyre damage is improper
inflation. Both over-inflation and under-inflation are
detrimental to tyre life. Tyre pressure should be
checked daily, preferably before the machine is placed
in operation. Refer to 'Tyre Inflation Table'.
The valve cores should be checked for leaks. Keep in
mind that valve cores are delicate mechanisms that
wear out in service; therefore, they should be replaced
with new ones when they become worn. Each tyre
should be equipped with a valve cap to prevent dirt
from damaging the valve core and causing air leakage.
Maintain Good Haul Roads
Because haul roads are considered temporary roads
they are frequently neglected. The better the haul
road, the longer the tyre and machine life of off-
highway machines.
Although it takes time and effort to maintain good haul
roads, the delay and cost of tyres and machine
breakdowns caused by poor haul roads is many times
greater.
Inspect Tyres Regularly
A systematic plan for tyre inspection will more than
pay for itself in lowered tyre costs per hour of
operation. All tyres should be checked regularly for
cuts, bruises, ply material breaks, excessive or
uneven wear, embedded foreign matter, and any other
damage which can be repaired. A considerable
increase in tyre service can be realized if tyre injuries
are repaired before they have progressed to the
irreparable stage.
The rim mounting nuts should also be checked
periodically and tightened to the torque specified.
Prevent Overloading
Off-highway machines are designed to carry a
maximum allowable payload. Excessive loading will
overstress both the machine and tyres and shorten the
life of both.
Prevent Contact with Oil
Prevent tyre contact with petroleum products. Rubber
that is exposed to oil, gasoline, or grease becomes
soft and spongy and deteriorates rapidly. Always avoid
driving machine through a puddle of gasoline, fuel oil,
lubricating oil, or grease. Never let a tyre stand in an
oil or grease spot overnight.
Store Tyres Properly
The best of care given to tyres in service by operators
and maintenance personnel can be completely
nullified by careless storage. Time is not the only
contributing factor to the deterioration of rubber
products. Therefore, tyres that are to be stored must
be protected from light, heat, oils, dirt, moisture, and
ozone. Stored tyres should be carefully covered with a
tarpaulin or some other suitable material, such as
opaque plastic sheets, to prevent contact with the
contaminants listed above.
Proper Handling of Tyres and Wheel Rim
Parts
Tyres should be stored vertically. Horizontal stacking
may compress the tyre walls, making inflation difficult. If
tyres are stored in racks, the lower supporting members
should provide as broad a surface as possible to the tyre
tread to avoid a concentration of load.
The beads of tubeless tyres must be protected from
damage or a faulty air seal will result. Do not use hooks,
cables, or chains in contact with the tyre beads when
lifting these tyres. If forklift trucks are used for handling,
they should be equipped with broad, well-rounded arms
to distribute the load and prevent damage to the tyre
bead. When handling tyres with the fork truck do not
scrape the fork across the bead.
Tubeless tyre rims perform an important function as part
of the assembly air seal. Proper care, therefore, must be
taken not to distort or mutilate the rim parts because they
must mate properly to form part of the basic air chamber.
Since the rim base and bead seat band are mating
surfaces, distortion may prevent easy assembly as well
as possibly resulting in no seal.
Never drop, tumble, or roll rim parts.
If rim parts are stored outdoors, they should be given a
protective coat of a good commercial primer.
Similar parts should be stacked neatly to prevent distortion.
Rear Axle Group - Wheel Rim and Tyre