Navistar WorkStar Series, Operator'S Manual

Page: 210 / 258

Maintenance Instructions
2. In a dual assembly, reverse the position of the tires if
one tire wears much faster than its mate.
3. On the drive axle, if heel and toe wear or alternate wheel
nut wear occurs, rotating the tires from one end of the
axle to the other end of the axle may help even out this
wear.
Tire Replacement
NOTE: Retread tires are not recommended for use on steering
axles of trucks.
• Front (Steering) Axle - Tires must be removed when tread
is worn to 4/32 inch (3 mm) or less. Retread or rotate worn
tires to drive position.
• Rear Axles - Tires must be removed when tread is worn to
2/32 inch (2 mm).
If rib tire is used 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 4/32 inch (3 mm) or less.
• Rear Axles - Tires must be removed when the tread is worn
to 2/32 inch (2 mm) or less. Tires identified with the word
regroovable molded on the sidewall can be regrooved. A
minimum of 3/32 (2.38 mm) of undertread must be left at the
bottom of the grooves.
Wheel and Tire Balancing
Out-of-round or out-of-balance wheels or tires can cause vehicle
vibration and bounce, and shimmy.
Replace damaged or
out-of-round wheels. Out-of-round tires and wheel assemblies
can be corrected by rechecking the tire relative to the wheel.
The tire and wheel assembly should thereafter be dynamically
balanced and reinspected while spinning for an out of round
condition.
Wear
Radial tires can exhibit three types of normal wear patterns,
even, erosion, or chamfer.
Even Wear is a sign that the tire is being properly used and
maintained.
Erosion Wear has also been called rolling wear, channel, or
river wear. Erosion wear is found more often at free rolling tires.
This is an indication that the tire is being used 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 will only occur at the edge of the tread. No
corrective action required. If erosion gets to be 1/16 inch (2 mm)
or more, the tire may be rotated to a drive axle.
Chamfer or Shoulder Wear, with tires inflated properly, 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. Overinflation is not effective in correcting this
effect.
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