Table of Contents
Advertisement
22 - 8
TIRES/WHEELS
TIRES (Continued)
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES
A quality air pressure gauge is recommended to
check tire pressure. After checking the air pressure,
replace valve cap finger tight.
DIAGNOSIS AND TESTING - TIRE NOISE OR
VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, vibration, wheel
defects, or possibly tire imbalance.
To find out if tires are causing the noise or vibra-
tion, drive the vehicle over a smooth road at varying
speeds. Note the noise level during acceleration and
deceleration. The engine, differential and exhaust
noises will change as speed varies, while the tire
noise will usually remain constant.
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS
Tread wear indicators are molded into the bottom
of the tread grooves. When tread depth is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band (Fig. 14).
Tire replacement is necessary when indicators
appear in two or more grooves or if localized balding
occurs.
DIAGNOSIS AND TESTING - TIRE WEAR
PATTERNS
Under inflation will cause wear on the shoulders of
tire. Over inflation will cause wear at the center of
tire.
1 - TREAD ACCEPTABLE
2 - TREAD UNACCEPTABLE
3 - WEAR INDICATOR
Excessive camber causes the tire to run at an
angle to the road. One side of tread is then worn
more than the other (Fig. 15).
Excessive toe-in or toe-out causes wear on the
tread edges and a feathered effect across the tread
(Fig. 15).
DIAGNOSIS AND TESTING - TIRE/VEHICLE
LEAD
Use the following Vehicle Lead Diagnosis And Cor-
rection Chart to diagnose and correct a vehicle lead
or drift problem (Fig. 16).
Fig. 15 Tire Wear Patterns
Fig. 14 Tread Wear Indicators
VA
Advertisement
Table of Contents
