During the process of wheel alignment, oftentimes the ride height of the vehicleis ignored or the average number is taken from the manual at best. In such cases, the alignment and other adjustments can be incorrect, if the ground clearance is not measured.
When ride height is so important that you must take it into account?
Ride height is the height of the clearance area between the road and the bottom of the car. This height can affect the behavior of the car while braking or cornering as well as its center of gravity.
Before starting the process of aligning the wheel, performing a pre-alignment check is as important as the ride height. During this check, you should focus on the condition of the tire and depth of its treads along with the pressure in the tires and the condition of bush and components of suspension as they can affect the ride height of that car.
Experienced people usually overlook ride height as it is not necessary to measure for every vehicle. But it can affect camber, toe, readings of the angle of inclination of steering wheel and caster if measured beforehand.
When you the need to measure ride height
Though this information can be found in the manufacturers’ manuals, still you must know the software of certain alignment systems includes this data too.
For instance, the system of Hunter will alert you and provide stepwise guidance at the appropriate time, through supportive diagrams and notes, during the process of wheel alignment.
How to measure ride height?
The methods and location of measuring ride height may vary depending upon the type of vehicle and its company.
The use of humble tape can be the easiest way to measure ride height of most vehicles. Certain companies like Renault and Citroen ask to measure from the sill/sub-frame to the ramp whereas vehicles like BMW ask to measure from center to arch of the wheel
There are some other vehicles which ask to weight the car with a full tank of petrol and a passenger to help in measuring their ride height. So, you must have a set of weights as an accessory for alignment, if you are providing wheel alignment services.
The ride height of Mercedes can be measured in angles by using Romess tool for this purpose. The ride height targets of a few 3D alignment systems like Hunter Elite TD can be attached and measure it automatically during the alignment process, at a right point of time. But they may also need the weight of the vehicle
Some people verify that they use factory specifications of ride height and do not examine the actual ground clearance. However, this is a misleading path.
So, the best way to measure ride height accurately is to follow the instructions of the manufacturer. It will allow you to calibrate the wheel alignment professionally.