Tire Maintenance And Condition; Tire Repair; Wide Tread Bias-Belted Tire Wear - Jeep 1979 CJ-5 Technical & Service Manual

2 1 4 WHEELS AND TIRES
Wide Tread Bias-Belted Tire Wear
Bias-belted wide tread tires have an initial wear char-
acteristic that is unique to this type of tire. It occurs as a
fairly rapid but even wear of the second and sixth tread
ribs (fig. 2H-4). Wear may occur at only one of the ribs
or at both ribs simultaneously. In some cases, a slight
cupping of these ribs may also develop in addition to
wear. Although wear develops rapidly, the degree of
wear is relatively light.
This wear characteristic is a normal condition with
wide tread bias-belted tires and and is related to the
tread deflection properties of these tires. When the
tread is pressed against the road surface, all tread ribs
do not support equal portions, of weight. The outer and
center ribs support the most weight while the second
and sixth ribs support the least. Because of the lighter
load on the second and sixth ribs, they are able to deflect
more and tend to slip and scrub slightly as the tire
rotates. This action causes more wear on these ribs.
Wear on the second and sixth ribs cannot be reduced
by over or underinflating the tires. Maximum benefit in
minimizing wear is obtained only by adhering to the
specifications recommended for tire inflation pressures,
tire rotation, and front wheel alignment.
F — T R E A D RIB WEAR — I
5 0 5 1 6
Fig. 2H-4
Wide Tread Bias-Belted Tire Wear
TIRE IAINTENANCE AND CONDITION
To maximize tire performance, inspect tires fre-
quently for signs of incorrect inflation and uneven wear
which may indicate a need for balancing, rotation, or
alignment. Tires should also be inspected frequently for
cuts, abrasions, stone bruises, blisters, or for objects
imbedded in the tire. Weekly inspection intervals are
recommended as a minimum. More frequent inspections
are recommended when extreme temperature changes
occur or where road surfaces are rough or occasionally
littered with debris.
As a further check of tire condition, tread wear in-
dicators are molded into the bottom of the tread grooves.
These indicators appear in the form of 1/2 inch (13 mm)
wide bands across the tread when it has worn to a
thickness of 1/16 inch (1.58 mm) or less (fig. 2H-5). The
tire should be replaced when these bands become visible.
T R E A D T R E A D
S T I L L GOOD WORN OUT
7 0 2 2 4
Fig. 2H-5 Tread Wear Indicators
A number of states have statutes concerning min-
imum permissable tread depths and use these indicators
as the tire wear limit.
Clean tires using a mild soap and water solution only
and rinse thoroughly with water. Do not use caustic
solutions or abrasive materials. To clean white sidewalls
and raised letters and numbers, use an approved white-
wall cleaner only. Do not use steel wool, wire brushes, or
materials having a mineral oil base such as gasoline,
paint thinner, or turpentine. These materials are harm-
ful to the tires and will also discolor the white sidewalls
and raised figures.
TIRE REPAIR
Punctured tires should be removed from the wheel
and permanently repaired from the inside using a com-
bination repair plug and vulcanized patch. When repair-
ing punctures, always follow the manufacturers
instructions for repair kit installation.
Punctures in the tread area only are repairable (fig.
2H-6). Never attempt to repair punctures in the tire
shoulders or sidewalls. In addition, never attempt to
repair any tire that has sustained the following damage:
• Bulges or blisters
• Ply separations
• Broken, cut, or cracked beads
• Fabric cracks or cuts
• Tires worn to the fabric or if wear indicators are
visible
• Punctures larger than 1/4 inch (6.35 mm) in
diameter