PTEN_0621 - 28

components and typically don't have the
same balance offset as that found on a steel
wheel. The dot is placed at the TPMS sensor
because that's the heavier section of
the rim. On the other hand, steel wheels
are not as refined and typically have a
balance factor, hence the need for the
diamond indicator.
Now, I'm sure you've seen a lot of tires
that are installed on vehicles where these
dots don't line up. I believe the main reason
for this is because personnel servicing
tires and wheels are not aware of this system.
Why do you want to do this? When
you follow this standard practice, you will
ultimately have a far better chance at successfully
balancing the entire wheel combination
with the least amount of weight
needed to achieve a zero-balance condition.
Another good reason for following
this practice is that you will be able to
use this as a reference point if a customer
returns after a tire repair complaining of a
vibration issue. The first inspection should
be to verify that none of the wheel weights
had prematurely departed the wheel.
Additionally, you can reference the dot
alignment versus the valve stem or indicator.
If you find that these have shifted, then
the tire has rotated on the rim. This could
be caused by a combination of things: too
much lubricant used on the bead during
assembly, the client recently experienced
a rapid breaking event, etc.
TIRE ROTATION
Tire rotation is a service that should be
performed on a regular schedule as per
the vehicle manufacturer's requirements.
The reason for rotation is so that we can
optimize tire wear evenly across all wheels.
In most cases, tire rotation intervals typically
run between 6,000 to 7,000 miles. On
some vehicles, you'll find that they are not
using the traditional wheel studs that are
affixed to the hub assembly, but rather they
use a screw-type lug nut. For these, you'll
want to have a special stud tool (Figure 2)
that will help with wheel assembly removal
and installation. This will also help you
prevent wheel contact with the brake rotor.
This is especially important on vehicles
equipped with carbon fiber brake rotors
Figure 2 - Tire stud tool
Figure 3 - Patch and plug
that can easily chip or break if a wheel were
to encounter it. Tire rotations are a great
opportunity to inspect a few items, such
as the brake pad thickness and suspension
components. Also, take note of the surface
between the rim and where it mounts to
the brake rotor or hub. If you remove a
wheel and observe a lot of rust corrosion
or buildup on these surfaces, you'll want
to take the time to properly clean and prep
the surfaces before reassembly, otherwise,
you will likely end up with numerous NVH
28 PTEN JUNE 2021 www.VehicleServicePros.com
violations. The date code is an often-overlooked
data metric. When installing new
tires, all of the date codes should be similar.
Additionally, the age of the tire should be
noted. Tires in excess of six years may call
for replacement. Check with the vehicle
manufacturer and tire manufacturer
for guidance.
TIRE REPAIR
Puncture repairs can only be performed
within certain limits. Proper puncture
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PTEN_0621

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