Car hub bearings used to be most used in pairs of single row tapered roller or ball bearings. With the development of technology, car wheel hub unit has been widely used. The range of use and use of hub bearing unit is growing, has developed to the third generation: the first generation is composed of double row angular contact bearings. The second generation has a flange used to fix the bearing on the outer raceway, which can be simply fixed by the bearing sleeve to the wheel shaft with a nut. It makes car maintenance easier. The third generation hub bearing unit is used with the bearing unit and anti-lock brake system ABS. The hub unit is designed to have an inner flange and an outer flange, the inner flange is bolted to the drive shaft, and the outer flange mounts the whole bearing together. Worn or damaged hub bearings or hub units will make your vehicle in the road of inappropriate and high cost failure, and even cause harm to your safety. In the use of the wheel hub bearing and install please note the following items: 1, in order to ensure maximum security and reliability, it is recommended that you no matter how long vehicles will check regularly whether the wheel hub bearing, pay attention to the bearing wear of early warning signals, including any rotating friction noise or suspension combination of abnormal wheel in turn. For rear-wheel drive vehicles, it is recommended to lubricate the front hub bearings until the vehicle is driven to 38,000 kilometers. When replacing the brake system, check the bearings 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 is possible that some rotating parts are in contact with non-rotating parts. If the noise in the bearing is confirmed, the bearing may be damaged and needs to be replaced. 3, because the working conditions of the front hub leading to the failure of the bearings on both sides are similar, so even if only one bearing is broken, it is recommended to replace it in pairs. 4, the hub bearing is more sensitive, in any case you need to use the right method and appropriate tools. In the process of storage, transportation and installation, bearing components should not be damaged. Some bearings require greater pressure to be pressed in, so special tools are needed. Always refer to the car's manufacturing instructions. 5. The bearing should be installed in a clean and tidy environment. Fine particles entering 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 strike the bearing with a hammer. Make sure that the bearing does not fall to the ground (or similar improper handling). Before installation, the condition of the shaft and bearing seat should also be checked. Even small wear will lead to poor fit, thus causing the early failure of the bearing. 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 lead to the entry of water or dust. Even the raceway of the sealing ring and the inner ring are damaged, resulting in permanent failure of the bearing. 7. There is a magnetic thrust ring in the sealing ring of the bearing equipped with ABS device. The thrust ring can not be impacted, impacted or collided with other magnetic fields. Remove them from the box before installation and keep them away from magnetic fields, such as electric motors or power tools used. When installing these bearings, the operation of the bearings is changed by observing the ABS alarm pins on the dashboard through road testing. 8, equipped with ABS magnetic thrust ring hub bearing, in order to determine which side of the thrust ring is installed, you can use a light and small thing * near the edge of the bearing, the magnetic force produced by the bearing will attract it. When installing, point the side of the magnetic thrust ring inward, facing the ABS sensitive element. Note: Incorrect installation may cause the brake system to fail to function. 9, many bearings are sealed, this kind of bearings in the whole life is not need to add grease. Other unsealed bearings such as double row tapered roller bearings must be lubricated when installed. Because the inner cavity of the bearing is different in size, it is difficult to determine how much oil to add. The most important thing is to ensure that there is oil in the bearing. If there is too much oil, the excess oil will ooze when the bearing rotates. General experience: During installation, the total amount of grease should account for 50% of the clearance of bearings. 10. When installing the lock nut, the torque varies greatly due to the different bearing types and bearing seats. Please refer to the relevant instructions.