If a ball joint breaks while you are driving, it can be very dangerous. The ball joint helps hold the wheel assembly to the suspension. When it fails, the suspension can collapse, and the wheel may tuck or fold under the vehicle. This often causes the car to drop on one corner, drag the tire, and pull sharply to that side. In some cases, the wheel and tire can separate or move outward dramatically. You may instantly lose steering control and come to a sudden stop, which can lead to a collision. Because of the risk of immediate loss of control, severely worn ball joints should be replaced before they fail.