The symptoms of broken car cages are: abnormal noise or jamming will occur during use. There are two kinds of ball cages on the car: inner ball cage and outer ball cage. To judge the quality of the ball cage, it is recommended to shake the ball cage by hand to feel the gap between the ball cages. Generally, the interior of the ball cage is closely matched, and there is almost no gap. If you feel that the gap is relatively large, it means that the ball cage is seriously worn, that is, it needs to be replaced. The inner ball cage of the car is connected to the differential of the gearbox, and the outer ball cage is connected to the wheel. Whether it is the power take-off or when the car turns, the outer ball cage plays a role. Automobile ball cage is generally composed of bell shell, Trident bearing steel ball, dust cover, harness ring and lubricating grease.