In the past, single-row tapered roller or ball bearings were used in pairs for the most common wheel hub bearings for cars. With the development of technology, car hub units have been widely used in cars. The use range and usage of wheel hub bearing units are increasing day by day, and it has now developed to the third generation: the first generation is composed of double row angular contact bearings. The second generation has a flange for fixing the bearing on the outer raceway, and the bearing can be simply sleeved on the axle and fixed with a nut. Makes the maintenance of the car easier. The third-generation wheel hub bearing unit uses the bearing unit to cooperate with the anti-lock brake system. The hub unit is designed with an inner flange and an outer flange. The inner flange is bolted to the drive shaft, and the outer flange installs the entire bearing together. Worn or damaged hub bearings or hub units will cause inappropriate and costly failures of your vehicle on the road, and even cause damage to your safety. Please pay attention to the following matters in the use and installation of hub bearings: 1. In order to ensure maximum safety and reliability, it is recommended that you always check the hub bearings regardless of the age of the vehicle-pay attention to whether the bearings have early warning of wear Signal: Including any frictional noise when turning or abnormal deceleration of the suspension combination wheel when turning. For rear-wheel drive vehicles, it is recommended that the front wheel hub bearings should be lubricated when the vehicle has traveled to 38,000 kilometers. When replacing the brake system, check the bearing and replace the oil seal. 2. If you hear the noise from the hub bearing part, first of all, it is important to find the location of the noise. There are many moving parts that may produce noise, and it may also be that some rotating parts are in contact with non-rotating parts. If it is confirmed that the noise is in the bearing, the bearing may be damaged and needs to be replaced. 3. Because the working conditions of the front wheel hub causing the bearing failure on both sides are similar, even if only one bearing is broken, it is recommended to replace it in pairs. 4. Hub bearings are more sensitive. In any case, you need to use the right method and the right tools. In the process of storage, transportation and installation, the components of the bearing cannot be damaged. Some bearings require greater pressure to press in, so special tools are required. Be sure to refer to the automobile manufacturing manual. 5. The bearing should be installed in a clean and tidy environment. The entry of fine particles into the bearing will also shorten the service life of the bearing. It is very important to maintain a clean environment when replacing bearings. It is not allowed to hit the bearing with a hammer, and be careful not to drop the bearing on the ground (or similar improper handling). The condition of the shaft and the bearing seat should also be checked before installation. Even slight abrasion can lead to poor fit and cause early bearing failure. 6. For the hub bearing unit, do not attempt to disassemble the hub bearing or adjust the seal ring of the hub unit, otherwise the seal ring will be damaged and water or dust will enter. Even the raceways of the sealing ring and the inner ring are damaged, causing permanent failure of the bearing. 7. There is a magnetic thrust ring in the sealing ring of the bearing equipped with ABS device. This thrust ring cannot be collided, impacted or collided with other magnetic fields. Take them out of the packaging box before installation and keep them away from magnetic fields, such as motors or power tools used. When installing these bearings, observe the ABS alarm pin on the instrument panel through a road condition test to change the operation of the bearings. 8. For wheel hub bearings equipped with ABS magnetic thrust ring, in order to determine which side the thrust ring is installed on, you can use a small object* near the edge of the bearing, and the magnetic force generated by the bearing will attract it. When installing, point the side with the magnetic thrust ring toward the inside, facing the sensitive element of ABS. Note: Incorrect installation may result in failure of the brake system. 9. Many bearings are sealed. This type of bearing does not need to be greased throughout its life. Other non-sealed bearings, such as double-row tapered roller bearings, must be lubricated with grease during installation. Due to the different sizes of the inner cavity of the bearing, it is difficult to determine how much grease to add. The most important thing is to ensure that there is grease in the bearing. If there is too much grease, the excess grease will leak out when the bearing rotates. General experience: When installing, the total amount of grease should account for 50% of the bearing clearance. 10. When installing the lock nut, the torque varies greatly due to the different bearing type and bearing seat. Pay attention to refer to the relevant instructions.