Steering and vibration complaints are not always the result
of improper alignment. Another possibility is tire lead. Tire lead is a condition
due to worn or improperly manufactured tires. Tire lead is the vehicle
deviation from a straight path on a level road without pressure on the
steering wheel. In order to determine if the vehicle has a tire lead problem,
refer to
Vehicle Leads/Pulls
in Suspension General Diagnosis.
Before making any adjustment that will affect the tire and wheel alignment,
make the following inspections to ensure correct alignment readings and alignment
adjustments.
| • | Inspect all tires for proper inflation pressures. Also verify
that all the tires have nearly even tread wear. |
| • | Inspect the control arm ball studs. If the studs are loose, correct
them before adjusting the tire and wheel alignment. Refer to
Ball Stud Check
in Front Suspension. |
| • | Inspect the vehicle trim height. If the height is out of limits
and a correction is to be made, make the correction before adjusting the alignment.
Refer to
Trim Height Specifications
in Specification General Diagnosis for the trim height chart. |
| • | Inspect the steering gear for looseness at the frame. |
| • | Inspect the control arms for loose bushings. |
| • | Inspect the stabilizer shaft for loose or missing parts. |
| • | Inspect the shock absorber and springs for improper operation. |
| • | Inspect the suspension and steering components for damage. Replace
parts as necessary. |
| • | Inspect the vehicle for stability. The fuel tank should be full,
or the vehicle should have compensating ballast. |
| • | Jounce the vehicle lightly three times in the rear and three times
in the front. |
Give consideration 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.
Give consideration also to the condition of the equipment being used
to adjust the alignment. Verify that you follow the equipment manufacturer's
instructions. Regardless of the equipment used to adjust the alignment,
the vehicle must be on a level surface, both front to rear and side to
side.
