The role of the lower arm on the car is: used to support the body, shock absorber; And buffer the vibration of the road. If it breaks the symptoms are as follows: reduced controllability and servability; Reduced safety performance (e.g. steering, braking, etc.); Abnormal sound (sound); Inaccurate positioning parameters, deviation, and cause other parts wear or damage (such as tire wear); Steering affected or even malfunction and other series of problems