Steering and vibration complaints are not always the result
of improper alignment. 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 to determine if the vehicle has
a tire lead problem. Before making any adjustment affecting wheel alignment,
make the following inspections to ensure correct alignment readings and adjustments.
| • | Inspect all the tires for proper inflation pressures. |
| • | Inspect that all tires are of the recommended size. |
| • | Inspect that all tires have about the same tread wear. |
| • | Inspect the wheel bearings for proper adjustment. Correct if necessary. |
| • | Inspect the control arm ball stud, inspect the relay rod and inspect
the tie rod ends. If they are loose, correct them before adjusting the wheel
alignment. Refer to Suspension General Diagnosis. |
| • | Inspect the vehicle trim height. If the vehicle trim height is
out of limits make the necessary corrections before adjusting the wheel alignment.
Refer to Trim Height Inspection Procedure |
| • | Inspect that the steering gear is not loose at the frame. |
| • | Inspect the lower control arms for loose bushings. |
| • | Inspect the stabilizer shafts for loose or missing parts. |
| • | Inspect for leaking or worn out struts. |
| • | Inspect for leaking or worn out shock absorbers. |
| • | Inspect for worn or loose strut upper mounts. |
| • | Inspect the remaining suspension and steering components for damage.
All worn parts must be replaced prior to adjusting the wheel alignment. |
| • | Inspect the vehicle for stability. The fuel tank should be full
or the vehicle should have compensating ballast. |
| • | Jounce the front of the vehicle lightly three times. |
| • | Jounce the rear of the vehicle lightly three times. |
Consideration must be given to excess loads, such as tool boxes, sample
cases, etc. If these items are normally carried in the vehicle, they should
remain in the vehicle during alignment adjustments. Consideration should also
be given to the condition of the equipment being used to adjust alignment.
Be sure to follow the equipment manufacturer's instructions. Regardless of
the equipment used to adjust alignment, the vehicle must be on a level surface,
both front-to-rear and side-to-side.
