Buick LeSabre 1965 Service Manual page 436

CHASSIS SUSPENSION TROUBLE DIAGNOSIS 7 - 9
A-UNDERINFLATION WEAR B-OVERINFLATION WEAR C-TOE-IN OR TOE-OUT WEAR
ONE SIDE OF TREAD
TWORN EXCESSIVELY
ROUNDED EDGE OF
OUTSIDE SHOULDER
CUPPED
D-SIDE OR CAMBER WEAR
E-CORNERING WEAR
F-MULTI-PROBLEM WEAR
Figure 7-6—Abnormal Tire Tread Wear Patterns
When tire inflation pressures are
maintained within the specified
limits (par. 1-2) the tire will
make a full contact across the
entire width of tread, thereby dis-
tributing the wear evenly over
the total surface of the entire
tread area.
d. Cross or Toe Tread Wear
When the front wheels have an
excessive amount of either toe-in
or toe-out, the tires are actually
dragged sideways when they tra-
vel straight down the road, and
cross wear or scraping action
takes place, rapidly wearing away
the tread of tires. This cross
wear condition will usually pro-
duce a tapered or feathered edge
on the ribs of the tire tread.
See Figure 7-4, View C. In most
cases this can be detected by
rubbing the hand across the tire
tread.
If the tapered or feathered edges
are on the inner sides of the ribs
on one or both sides, it indicates
that one or both tires have exces-
sive toe-in, while the same con-
dition in the outer sides of ribs
indicate excessive toe-out. Usu-
ally, excessive toe-in causes ex-
cessive tire wear on the outer
edge of the right front tire and
toe-out causes tire wear on the
inner edge of the left front tire.
See paragraph 7-18 for toe-in
correction.
Cornering wear caused by high
speed driving on curves (subpar.
f, following) sometimes has the
appearance of toe wear. Care
must be used to distinguish be-
tween these two types of wear so
that the proper corrective meas-
ures will be used.
e. Side or Camber Wear
Excessive wheel camber, either
positive or negative, causes the
tire to run at such an angle to
the road surface that one side
of the tread wears much more
than the other. See Figure 7-4,
View D.
The amount or angle of the cam-
ber wear will be governed by the
amount of positive or negative
camber. Tire tread wear very
similar in appearance to camber
wear may be caused by driving on
turns at excessive speeds. This
"cornering" tread wear (subpar.
f, below) cannot be corrected by
change of camber angle.
Adjustments for specified camber
is covered in paragraph 7-18.
f. Cornering Tread Wear
The modern independently sprung
automobile allows the driver to
negotiate turns at a high rate of
speed with a greater feeling of
safety. This fact is responsible
for a comparatively new type of