.
1-32 GENERALINFORMATIONAND MAINTENANCE
CONDITION
EFFECT
CAUSE
CORRECTION UNDER-INFLATION
EXCESSIVE SPEED’ WORN OR OUT-
OF-ALIGNMENT
ADJUST PRESSURE TO
SPECIFICATIONS WHEN
TIRES ARE COOL
ROTATE TIRES
/ BALANCE WHEELS INSPECT SUSPENSION
HAVE TIRE INSPECTED FOR FURTHER USE.
lCCSi267 ig. 144 Common tire wear patterns and causes
1~~~1265 Fig. 145 Tread wear indicators will appear
when the tire is worn
inflation, do not drive more than a mile before check-
ing. A cold tire is generally one that has not been dri-
ven for more than three hours.
A plate or sticker is normally provided somewhere
in the vehicle (door post, hood, tailgate or trunk lid)
which shows the proper pressure for the tires. Never
counteract excessive pressure build-up by bleeding
off air pressure (letting some air out). This will cause
the tire to run hotter and wear quicker.
Never exceed the maximum tire pressure
embossed on the tire! This is the pressure to
be used when the tire is at maximum load-
ing, but it is rarely the correct pressure for
everyday driving. Consult the owner’s man-
ual or the tire pressure sticker for the correct
tire pressure.
Once you’ve maintained the correct tire pressures
for several weeks, you’ll be familiar with the vehicle’s
braking and handling personality. Slight adjustments
in tire pressures can fine-tune these characteristics,
1~~~1264 Fig. 146 Accurate tread depth indicators are
inexuensive and handv
Fig. 147 A penny works well for a quick
check of tread death
but never change the cold pressure specification by
more than 2 psi. A slightly softer tire pressure will
give a softer ride but also yield lower fuel mileage. A
slightly harder tire will give crisper dry road handling
but can cause skidding on wet surfaces. Unless
you’re fully attuned to the vehicle, stick to the recom-
mended inflation pressures.
All tires made since 1968 have built-in tread wear
indicator bars that show up as j/2 in. (13mm) wide
smooth bands across the bre when V,~ in. (1.5mm) of
tread remains. The appearance of tread wear indica-
tors means that the tires should be replaced. In fact,
many states have laws prohibiting the use of tires
with less than this amount of tread.
You can check your own tread depth with an inex-
pensive gauge or by using a Lincoln head penny.
Shp the Lrncoln penny (with Lincoln’s head upside- down) into several tread grooves. If you can see the
top of Lincoln’s head in 2 adjacent grooves, the tire
has less than V,~ in. (1.5mm) tread left and should be
replaced. You can measure snow tires in the same
manner by using the “tails” side of the Lincoln
penny. If you can see the top of the Lincoln memor-
ial, its time to replace the snow tire(s).
CAREOFSPECIALWHEELS
If you have invested money in magnesium, alu-
minum alloy or sport wheels, special precautions
should be taken to make sure your investment is not
wasted and that your special wheels look good for the
life of the vehicle.
Special wheels are easily damaged and/or
scratched. Occasionally check the rims for cracking,
impact damage or air leaks. If any of these are found,
replace the wheel. But in order to prevent this type of
damage and the costly replacement of a special
wheel, observe the following precautions:
l Use extra care not to damage the wheels dur-
ing removal, installation, balancing, etc. After re-
moval of the wheels from the vehicle, place them on a
mat or other protective surface. If they are to be
stored for any length of time, support them on strips
of wood. Never store tires and wheels upright; the
tread may develop flat spots.
l When driving, watch for hazards; it doesn’t take
much to crack a wheel.
l When washing, use a mild soap or non-abra-
sive dish detergent (keeping in mind that detergent
tends to remove wax). Avoid cleansers with abrasives
or the use of hard brushes. There are many cleaners
and polishes for special wheels.
l If possrble, remove the wheels during the win-
ter. Salt and sand used for snow removal can se-
verely damage the finish of a wheel.
l Make certain the recommended lug nut torque
is never exceeded or the wheel may crack. Never use
snow chains on special wheels; severe scratching
will occur.
