All rotating and moving parts of the car must be lubricated, or they will wear quickly. Some are liquid lubricants that need to be replaced regularly, and some are greases that do not need to be replaced. For example, lubricating grease is used in the ball cage of the semi-axle and in the outer ball joint of the tie rod of the steering gear. As long as the rubber sleeve surrounding the grease is not damaged and the grease leaks, it does not need to be replaced for life.

If the rubber sleeve is damaged, both the grease and the rubber sleeve must be replaced, because the grease will be thrown out if it is not replaced, and the lack of grease will eventually cause poor lubrication. Bearings are often an important part of tires. In order to make the car run safely, regular maintenance and replacement of the bearings is the key. If the maintenance is used properly, the car's bearings can generally be used for about 100,000 kilometers.

During assembly or installation, if the internal clearance of the bearing is too large or too small, or in some cases, the preload is too high, which may cause early damage and shorten the bearing life. In addition to causing downtime and costly maintenance, improper bearing assembly and installation may have more negative effects, such as affecting the operation of other parts and shortening their service life.