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 following components for looseness or wear. Repair the components as necessary. |
• | 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:
- Disconnect the negative battery cable for more than 2 seconds. Refer to
Battery Negative Cable Disconnection and Connection.
- Connect the negative battery cable.
- Using the scan tool, perform the yaw rate sensor zero point calibration under the special functions menu.
- Center the vehicle on the alignment rack.
- Push down on the front bumper 3 times.
- Push down on the rear bumper 3 times.
- Install the alignment heads to the vehicle.
- Select the program on the alignment equipment.
- Compensate, level, and lock all of the alignment heads.
- Measure the wheel alignment.
- Record the measurements.
- Compare the measurements to the specifications. Refer to
Wheel Alignment Specifications.
- If equipped with upper control arms in the rear suspension, and adjustment is necessary, adjust the rear camber and toe. Refer to
Rear Camber and Toe Adjustment.
- If necessary, adjust the front camber. Refer to
Front Camber Adjustment.
- If necessary, adjust the front toe. Refer to
Wheel Alignment - Steering Wheel Angle and/or Front Toe Adjustment.
- Ensure the front tires are in the straight ahead position.
- Disconnect the negative battery cable for more than 2 seconds. Refer to
Battery Negative Cable Disconnection and Connection.
- Connect the negative battery cable.
- Using the scan tool, perform the yaw rate sensor zero point calibration under the special functions menu.
- Perform the steering angle sensor zero point calibration. Refer to
Steering Angle Sensor Initialization and Steering Shaft Torque Sensor Zero Point Calibration.
- Lower the vehicle from the alignment rack.