Wheel Alignment Measurement Front
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 for worn wheel bearings. Replace if necessary, refer to
Wheel Bearing/Hub Replacement - Front in Front Suspension. |
| • | Inspect the control arm ball joints and the tie rod ends. If they
are loose, tighten them before adjusting the wheel alignment. Refer to Fastener
Tightening Specifications in Power Steering System or Fastener Tightening
Specifications in Front Suspension. |
| • | Inspect the runout of the wheels. Refer to Trim Height Specifications. |
| • | 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 Tire and Wheel Runout Specifications in Vibration Diagnosis
and Correction. |
| • | Inspect that the steering gear is not loose at the frame. Refer
to Power Steering Gear Replacement in Power Steering System. |
| • | Inspect the lower control arms for looseness. Refer to Lower Control
Arm Replacement in Front Suspension. |
| • | Inspect the stabilizer shafts for loose or missing parts. Refer
to Stabilizer Shaft Replacement in Front Suspension. |
| • | Inspect for worn struts. Refer to Strut Assembly Replacement in
Front Suspension. |
| • | 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. |
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.
Satisfactory vehicle operation may occur over a wide range
of alignment settings. However, should the settings vary beyond the specifications,
the alignment angles should be corrected.
Perform the following steps to measure the wheel alignment angles:
- Install the alignment equipment according to the manufacturer's
instructions.
- Jounce the front bumpers lightly three times and jounce the rear
bumpers lightly three times to normalize the suspension prior to measuring
the angles.
- Measure the alignment angles.
- Record the readings. If adjustments are required, make them in
the following order:
Wheel Alignment Measurement Rear
Rear Wheel Alignment
Rear wheel alignment is not adjustable. If the rear camber and toe
angles are not within specifications, inspect for underbody or suspension
damage. Refer to Alignment Checking in Frame and Underbody.
