Wheel Alignment Measurement
- Wheel and Tyre imbalance. Refer to Tire and Wheel Assembly Balancing - Off Vehicle , or Tire and Wheel Assembly Balancing - On-Vehicle
- Tyre lead due to wear, incorrectly manufactured or incorrectly mounted tyres. Refer to Radial Tire Lead/Pull Correction .
- Before performing any adjustments affecting wheel alignment, perform the following inspections and adjustments in order to ensure correct alignment readings.
Steering and vibration concerns are not always the result of incorrect alignment. Other causes could include:
- Inspect tyres for correct inflation. Refer to Tire Inflation Pressure Specifications .
- Inspect tyres for irregular wear. Refer to Tire Diagnosis - Irregular or Premature Wear .
- Inspect the run out of the wheels and tyres. Refer to Tire and Wheel Assembly Runout Measurement - On-Vehicle .
- Inspect the wheel hub end float.
- For front wheel hub Refer to Front Wheel Hub Assembly Inspection
- For rear wheel hub Refer to Rear Wheel Hub Assembly Inspection
- Inspect the front suspension and steering ball joints for wear and damage. Refer to Ball Joint Inspection .
- Inspect the suspension control arms and stabiliser bar for wear and damage.
- Inspect the steering gear for looseness.
- Inspect the struts/shock absorbers for wear and damage. Refer to Suspension Strut and Shock Absorber Testing - On Vehicle .
- Inspect the vehicle trim height. Refer to Trim Height Inspection .
- Inspect the steering wheel for excessive drag or poor return due to stiff or binding suspension components.
- Inspect the fuel level. The fuel tank should be full or the vehicle should have compensating load added.
- Install the alignment equipment according to the manufacturer's instructions.
- Bounce the front and rear bumpers 3 times prior to checking the wheel alignment.
- Measure the alignment angles and record the readings.
- Adjust alignment angles to vehicle specifications, if necessary. Refer to Wheel Alignment Specifications .
Give consideration to excess loads such as tool boxes, sample cases, etc. If normally carried in the vehicle, these items should remain in the vehicle during the alignment adjustments. Give consideration also to the condition of the equipment being used for the alignment. Follow the equipment manufacturer's instructions.
Perform the following steps to measure the front and rear alignment angles:
Satisfactory vehicle operation may occur over a wide range of alignment settings. However, if the settings are not within the allowable specifications, correct the alignment to the correct specifications. Refer to Wheel Alignment Specifications .
When performing adjustments to vehicles requiring a four wheel alignment, set the rear wheel alignment angles first in order to obtain the correct front alignment angles.