If the ball joint of the lower swing arm of the car chassis is broken, the wheels will become splayed
If the upper and lower ball joints break, the vehicle will lose control. The lower ball head broke and the wheel came off directly, falling down in a figure-eight shape. The upper ball head is broken and the wheel is tilted inwards.
If the rubber wear is serious, there should be looseness. The vehicle is unstable, shakes at high speed, and has poor tracking. It's best to replace them all. Regardless of which ball head is broken, it means it has been used for a long time. If you replace one today, it does not necessarily mean that the other one will be broken tomorrow. Just replace them for safety.