TM 10-4610-239-24
TM 08580B-24/3
HOW TO READ TIRE WEAR
THE WAY TIRES WEAR IS A GOOD INDICATOR OF OTHER PARTS OF THE SUSPENSION. ABNORMAL
WEAR PATTERNS ARE OFTEN CAUSED BY THE NEED FOR SIMPLE TIRE MAINTENANCE.
EXCESSIVE WEAR AT THE CENTER OF THE TREAD INDICATES THAT
THE AIR PRESSURE IN THE TIRE IS TOO HIGH. THE TIRE IS RIDING
ON THE CENTER OF THE TREAD AND WEARING IT PREMATURELY
THIS TYPE OF WEAR RESULTS FROM UNDER-INFLATION. WHEN A
TIRE IS UNDER-INFLATED, THERE TOO MUCH CONTACT WITH THE
ROAD BY THE OUTER TREADS, WHICH WEAR PREMATURELY WHEN
THIS TYPE OF WEAR OCCURS, AND THE TIRE PRESSURE IS KNOWN
TO BE CORRECT, A BENT AXLE OR OUT OF ADJUSTMENT WHEEL
BEARINGS COULD BE INDICATED.
FEATHERING IS A CONDITION WHEN THE EDGE OF EACH TREAD
RIB DEVELOPS A SLIGHTLY ROUNDED EDGE ON ONE SIDE AND A
SHARP EDGE ON THE OTHER. BY RUNNING YOUR HAND OVER THE
TIRE, YOU CAN USUALLY FEEL THE SHARPER EDGES BEFORE
YOU'LL BE ABLE TO SEE THEM. THE MOST COMMON CAUSE OF
ZFEAING IS A BENT AXLE.
WHEN AN INNER OR OUTER RIB WEARS FASTER THAN THE REST
OF THE TIRE, THE NEED FOR WHEEL BEARING ADJUSTMENT IS
INDICATED. THERE IS EXCESSIVE WEIGHT ON ONE SIDE OF
TRAILER, CAUSING THE WHEEL TO LEAN TOO MUCH, PUTTING
EXCESSIVE LOAD ON ONE SIDE OF THE TIRE. MISALIGNMENT
COULD ALSO BE DUE TO SAGGING SPRINGS. BE SURE THE
VEHICLE IS LOADED EVENLY.
CUPS OR SCALLOPED DIPS APPEARING AROUND THE EDGE OF
THE TREAD ALMOST ALWAYS INDICATE WORN (SOMETIMES BENT)
SUSPENSION PARTS. ANY WORN COMPONENT THAT CONNECTS
THE WHEEL TO THE SUSPENSION CAN CAUSE THIS TYPE OF
WEAR. OCCASIONALLY, WHEELS THAT ARE OUT OF BALANCE WILL
WEAR LIKE THIS, BUT WHEEL IMBALANCE USUALLY SHOWS UP AS
BALD SPOTS BETWEEN THE OUTSIDE EDGES AND CENTER OF THE
TREAD.
SECOND-RIB WEAR CAN BEKEPT TO A MINIMUM BY PAYING
CAREFUL ATTENTION TO TIRE PRESSURE AND FREQUENTLY
ROTATING THE TIRES. THIS IS OFTEN CONSIDERED NORMAL
WEAR.
Figure 2-7. Tire Wear Chart
2-35
