Preliminary Diagnosis

Question the Customer
The preliminary diagnosis starts with the customer interview. The history of the concern must be investigated: When was it first noticed? Did it appear suddenly or gradually? Did any abnormal occurrence coincide with or precede its appearance (such as pothole or curb impacts, minor collisions, etc.)? Were any repair procedures performed or parts installed? It is also necessary to know any special conditions affecting the appearance and degree of the concern, such as road speed, type of road, drive mode, engine temperature, ambient temperature, etc.
A gradual appearance of the concern indicates a deterioration of a component, such as tires or wheel bearings.
A sudden appearance of the concern could indicate a lost wheel balance weight.