New vehicle features mean performing a quick toe adjustment could cause more problems
You have probably seen the results of a “toe and go” alignment, a service that ignores camber, caster and diagnostic angles like SAI and included angle.
The result might be a straight steering wheel, but the driver knows something is not right because it does not feel right going around turns. On some vehicles, you might be able to get away with a “toe and go” alignment. But with stability control and advanced safety features, the sensors might catch your shortcut.
Scanner For The Chassis
Should a shop charge more for alignments? Yes. Your alignment bay should be treated as a colossal scan tool that can pull the angles from the vehicle so they can be used for diagnostics of the chassis and suspension. Adjustments performed like camber and toe are just like calibrating a sensor, but it is mechanical.
The other factor changing alignment is the growing population of vehicles with stability control systems. Some of these require extra steps after the angles are adjusted to calibrate the steering angle sensor.
The vehicle knows how it is traveling down the road with the data from the steering angle, yaw and lateral acceleration sensors. If it sees a steering angle above a certain level and the yaw and accelerometers say it is going straight, it might just set a code. The pull could be caused by a cross camber condition, the thrust angle or a low tire. The system only sees the alignment error through the sensors. For some lane-departure systems, it might cause false warnings that annoy the driver.
It is only going to get worse as more vehicles with advanced safety systems are coming out of warranty. These vehicles require an accurate alignment and calibration of radar and camera sensors.
The Basics
No matter how advanced the ADAS or autonomous driving system can be, the pre-alignment inspection with a tire pressure gauge, tape measure and your eyeballs becomes even more important.
Always check tire inflation pressures because a low tire will pull. It’s also important to note tire sizes. A car will pull toward the side with the smallest tires or the side with wider tires. A wide tire offers higher rolling resistance than a narrower tire. Wide tires also tend to be more sensitive to road crown steer than narrower ones.
Measuring ride height becomes even more critical with more advanced vehicles. Changes in the ride height can change the caster angles and steering feel. But for vehicles with cameras and radar sensors, ride height is even more critical. If the ride height changes, so does the angle of the camera in relation to the road.
Inspecting the entire suspension is critical because sometimes the alignment angle sitting on the alignment rack is just a static snapshot. If bushings are worn out, the alignment angles can change.
When angles change and the vehicle starts to pull, some electric power steering systems will attempt to add assist. It does this to compensate for normal pulls like road crown. Pull compensation is designed to reduce driver fatigue. But if the pull is too great, constantly having to apply assist may cause the electric power steering motor to overheat.
Adjustments
Modern vehicles are built to higher tolerances. The need for built-in adjustments for camber and caster are not needed at the factory. If you ask any OE engineer, they will say that if the vehicle is out of specification, it is due to defective, damaged or worn components. This is true, but it is not an economical approach for aligning an older vehicle that needs a little more or less caster or camber. This is where aftermarket alignment kits can help.
Test Drive
With systems like lane departure and automatic cruise control that can steer the vehicle, the post-alignment test drive takes on a whole new meaning. Many systems, like lane departure, do not activate until a specific speed is reached and the road markings are present. It is critical to look at the service information to find procedures and the activation criteria. If you fail to complete this step, the customer might be back complaining that you broke their vehicle.
