Landoll 330A, Operator'S Manual

Page: 51 / 62

4-11 TIRE MAINTENANCE
4-11.1 Tire Inflation . Tire inflation will cause
tire to ground contact characteristics as
shown in Figure 4-16 . Tire inflation should
be checked daily while the tire is cold, and
during road stops. Checking the tire pres-
sures while tires are hot will give a faulty in-
creased pressure reading. Adjusting tire air
pressure to the specified amount while tires
are hot will produce improper tire to road
contact and thus abnormal wear. Do not ex-
ceed cold inflation pressure listed on the
semitrailer VIN plate located on the front of
the semitrailer. Exceeding cold inflation pres-
sure will result in damaged tire bodies, rims,
and wheels. Replace all valve stem caps
when pressure checking/adjusting has been
completed. Remove any foreign objects from
between duals.
4-11.2 Tire Matching . Both tires on the same
spindle must be the same size in order to
properly distribute the load and braking forces
between them. The tire must be mounted on a
rim and properly inflated before measuring. If
there is an allowable difference in size the
smaller tire should be mounted to the inside
position of the duals.
a. Tape Measuring Method : Measure around
each tire on the tread surface. A maximum
difference of 3/4" is allowed between the two
mating tires of a dual (See Figure 4-17).
b. Straight Edge or String Method : (This
method can not be used if tire and wheel as-
semblies are not mounted on the axle.) Jack
semitrailer up until the wheels are off of the
ground. Hold a straight edge against the tires
of both ends of an axle. A gap at one tire indi-
cates a smaller tire. A maximum of 1/8" gap is
allowed (See Figure 4-18) .
4-11.3 Mounting Tire and Wheel
a. Make sure that all mounting surfaces are
clean and free of rust, dirt or paint. A wire
brush may be used to clean these surfaces
(See Figure 4-19) .
b. Position the inner disc wheel over the studs,
being careful not to damage the stud threads.
Make sure that the disc wheel is flat against
the mounting surface and that there is clear-
ance between the disc wheel taper and brake
drum.
c. Install the inner capnuts on the studs and
tighten to fifty foot-pounds using the se-
quence illustrated in Figure 4-20 . Make cer-
tain that the left-handed threads are installed
on the driver side of the vehicle and the right-
handed threads are installed on the curbside
of the vehicle.
d. Tighten the inner capnuts to full torque of
450 to 500 foot-pounds using the sequence
shown in Figure 4-20 .
e. Position the outer disc wheel over the
capnuts being careful not to damage the inner
capnut threads. Be sure the valve stems for
both the inner and outer tire are accessible.
4-23
Fig. 4-17 Measuring Tape Method
Fig. 4-18 Straight Edge Method