Wheel Alignment Measurement

Steering and vibration concerns are not always the result of improper wheel alignment. One possible cause is wheel and tire imbalance. Another possibility is a tire lead/pull condition due to worn or improperly manufactured tires. At a constant highway speed on a typical straight road, lead/pull is the amount of effort required at the steering wheel to maintain the vehicle's straight path. Refer to Radial Tire Lead/Pull Correction in order to determine if the vehicle has a tire lead/pull condition.

Before adjusting the wheel alignment, perform the following inspections and adjustments in order to ensure correct wheel alignment measurements:

• Measure the inflation pressure of each tire. Adjust the tire pressure to the specification on the tire placard.
• Verify the sizes of the tires and the wheels match the specifications on the tire placard.
• Inspect the tires and the wheels for damage and debris.
• Inspect the tires for irregular or premature wear. Refer to Tire Diagnosis - Irregular or Premature Wear .
• Inspect the tires and the wheels for runout. If necessary, measure the runout of the tires and the wheels. Refer to Tire and Wheel Assembly Runout Measurement - On-Vehicle .
• Inspect the wheel bearings for backlash and excessive play. Refer to Wheel Bearings Diagnosis .
• Inspect the following components for looseness or wear. Repair the components as necessary.
  • The knuckles
  • The control arms
  • The ball joints
  • The bushings
  • The tie rods
  • The steering gear
  • The stabilizer shafts
  • The springs
• Inspect the struts and the shock absorbers for wear, leaks, and any noticeable noises. Refer to Suspension Strut and Shock Absorber Testing - On Vehicle .
• Inspect the vehicle trim height. Refer to Trim Height Inspection .
• Inspect the steering system for excessive drag or poor return due to stiff or corroded components.
• Inspect the fuel level. If the fuel tank is not full, add weight to the vehicle in order to simulate a full fuel tank.

Give consideration to excess loads, such as toolboxes or sample cases. If normally carried in the vehicle, these items should remain in the vehicle during alignment adjustments. Also, give consideration 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 wheel alignment angles. However, if the wheel alignment angles are not within the range of specifications, adjust the wheel alignment to the specifications. Refer to Wheel Alignment Specifications .

Perform the following steps in order to measure and adjust the wheel alignment angles:

1. Center the vehicle on the alignment rack.
2. Push down on the front bumper 3 times.
3. Push down on the rear bumper 3 times.
4. Install the alignment heads to the vehicle.
5. Select the program on the alignment equipment.
6. Compensate, level, and lock all of the alignment heads.
7. Measure the wheel alignment.
8. Record the measurements.
9. Compare the measurements to the specifications. Refer to Wheel Alignment Specifications .
10. If necessary, adjust the front camber. Refer to Front Camber Adjustment .
11. If necessary, adjust the front toe. Refer to Front Toe Adjustment .
12. Lower the vehicle from the alignment rack.