Steering and vibration complaints are not always the result
of improper alignment. One possible cause is wheel and tire imbalance. Another
possibility is tire lead due to worn or improperly manufactured tires. Lead
is the vehicle deviation from a straight path on a level road without pressure
on the steering wheel. Refer to Radial Tire Lead/Pull Correction
in Tires and Wheels in order to determine
if the vehicle has a tire lead problem.
Before making any adjustment affecting wheel alignment, perform the
following inspections and adjustments in order to ensure correct alignment
readings:
| • | Inspect the tires for the following conditions: |
| • | Inspect the runout of the wheels. Refer to Tire and Wheel Runout Specifications
in Vibration Diagnosis. |
| • | Inspect the wheel bearings for backlash and excessive play. Refer
to
Wheel Bearings Diagnosis
in
Suspension General Diagnosis. |
| • | Inspect the following components for looseness or wear: |
| - | The control arm ball studs |
| - | The control arm bushings |
| • | Inspect the struts for leaks. |
| • | Inspect the remaining suspension and steering components for damage.
Replace all damaged parts prior to adjusting wheel alignment. |
| • | Inspect the fuel level. The fuel tank should be full or the vehicle
should have compensating ballast. |
Give consideration to excess loads, such as tool boxes, sample cases,
etc. If normally carried in the vehicle, these items should remain in the
vehicle during alignment adjustments. Give consideration also to the condition
of the equipment being used for the alignment. Follow the equipment manufacturer's
instructions.
Satisfactory vehicle operation may occur over a wide range
of alignment settings. However, if the setting exceeds the service allowable
specifications, correct the alignment to the service preferred specifications.
Refer to
Wheel Alignment Specifications
.
Perform the following steps to measure the front alignment angles:
- Install the alignment equipment according to the manufacturer's
instructions.
- Perform the following procedure to normalize the suspension prior
to measuring the angles:
| 2.1. | Jounce the front bumper lightly three times. |
| 2.2. | Jounce the rear bumper lightly three times. |
- Measure the alignment angles.
- Record the readings. Make adjustments in the following order:
