Ideally, road test the vehicle with the owner before an alignment
check is made. The road test can give you clues in order to better diagnose
the following problems:
| • | Worn control arm bushings |
| • | Loose rack and pinion mounts |
| • | Damaged or unbalanced tires |
Before starting the alignment, you must bring obvious conditions to
the owner's attention, such as the following:
| • | A waddle feeling in the back of the vehicle may be a bent wheel,
but most often a waddle indicates a belt shift in one of the rear tires. |
| • | Steering wheel shimmy may be a bent wheel, but is most often caused
by a belt shift or dynamic imbalance in the front tires. |
| • | Vibration in the steering wheels or the floor pan is often caused
by static imbalance or radial runout of the front tires. |
| • | Steering and vibration complaints are not always the result of
improper alignment. |
| • | Tire lead is due to worn or improperly manufactured tires. Lead
is the vehicle's deviation from a straight path on a level road without pressure
on the steering wheel. Refer to Diagnosis. |
Check the suspension and steering systems for worn suspension or broken
parts before checking the wheel alignment. Looseness in the suspension will
prevent setting any of the alignment angles accurately. Check all the ball
joints for wear. Any wear in the steering linkage or associated parts will
cause a toe variance. Squeeze the seal (boot) with one hand so that you can
feel the inner ball and socket joint. At the same time push on the tire with
the other hand. Replace the tie rod or ball joint if any looseness is felt.
Check the steering gear mounts. A steering gear that is not securely
mounted can cause vague steering and bump steer. In order to check this condition,
place the tires on the ground with the wheels in the straight-ahead position.
Using an assistant, turn the steering wheel back and forth and watch the
steering gear. Inspect the following components if the gear moves back and
forth as the steering wheel is turned:
It is unusual to have a loose steering wheel problem on a vehicle with
rack and pinion steering and a strut front suspension. Check the following
components if a problem occurs:
Perform the following inspections to ensure correct alignment readings
and alignment adjustments before making any adjustment affecting the wheel
alignment:
- Inspect all the tires for the following conditions:
| • | For proper inflation pressures. |
| • | Verify that the tires have about the same tread wear. |
| • | Verify that the tires are the same size. |
| • | Verify that the tires are the same type. |
- Inspect the hub and the bearing assemblies for excessive wear.
Correct if necessary.
- Inspect the ball joints and tie rod ends. If loose, replace before
adjusting.
- Inspect runout of wheels and tires.
- Inspect the vehicle trim height. Make any corrections before adjusting
the alignment if the height is out of limits.
- Inspect the strut dampeners for proper operation.
- Inspect the control arms for loose bushings.
- Inspect the stabilizer shaft for loose or missing parts.
- Inspect the suspension and steering parts for damage. Replace
the parts as necessary.
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 to the condition
of the equipment used to adjust the alignment. Follow the equipment
manufacturer's instructions. Regardless of the equipment used to adjust the
alignment, the vehicle must be on a level surface, fore and aft and sideways.
