Operation CHARM: Car repair manuals for everyone.

Incorrect Tire Inflation Pressure


Incorrect tire inflation pressure can lead to the following symptoms: Over-inflation
- Hard ride.
- Tire bruising or carcass damage.
- Rapid tread wear at center of tire.
Under-inflation
- Tire squeal on turns.
- High steering effort.
- Rapid tread wear on tire edges.
- Tire bruises or bead rupture.
- Tire cord breakage.
- High tire temperatures.
- Degraded handling.
- Reduced fuel economy.
Unequal-inflation pressure on same axle
- Uneven braking.
- Steering lead or pull.
- Degraded handling.
- Swerve on acceleration.

WHEEL RUNOUT

MEASURING





Wheel runout should be measured with an accurate dial indicator. Measurements may be taken with wheel installed on vehicle (be sure wheel bearings do not have excessive free play) or off vehicle on an accurate mounting fixture (such as a wheel balancing machine). Measure the (1) radial and (2) lateral runout of both the (3) inboard and (4) outboard bead flanges.
1. Place dial indicator in a rigid fixture and position against wheel.
2. Slowly rotate the wheel one full revolution while observing dial indicator.
3. Rotate wheel to position where lowest dial indicator reading was obtained.
4. Zero dial indicator.








5. Slowly rotate wheel one full revolution while observing dial indicator.
6. Record highest dial indicator reading. This is the wheel runout.

IMPORTANT: Disregard any indicator readings due to welds, scratches, paint runs, etc.