BMW rims for sale

1. In order to maximize safety and reliability, it is recommended that you always check the hub bearings no matter how old the car is-pay attention to whether the bearings have early warning signs of wear: including any friction noise during rotation 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 travels 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 bearing part of the hub, first of all, it is important to find the location where the noise occurs.There are many moving parts that may produce noise, and it may also be that some rotating parts have come into contact with non-rotating parts.If it is confirmed that it is noise in the bearing, the bearing may be damaged and needs to be replaced. 3. Because the working conditions for the failure of the bearings on both sides of the front wheel hub are similar, even if only one bearing is broken, it is recommended to replace it in pairs. 4. Hub bearings are more sensitive, and the correct methods and suitable tools need to be used in any case.During the storage, transportation and installation process, the bearing parts cannot be damaged.Some bearings require greater pressure to be pressed in, so special tools are required, and you must refer to the automobile manufacturing manual. 5. When installing the bearing, it should be 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 strike the bearing with a hammer, and be careful that the bearing does not fall to the ground (or similar improper handling).The condition of the shaft and bearing seat should also be checked before installation. Even minor wear and tear can lead to poor fit, which can cause early bearing failure. 6. For the hub bearing unit, do not attempt to disassemble the hub bearing or adjust the sealing ring of the hub unit, otherwise the sealing ring will be damaged and water or dust will enter.Even the raceway of the sealing ring and the inner ring are damaged, causing permanent bearing failure. 7. There is a magnetic thrust ring in the sealing ring equipped with the bearing of the ABS device. This thrust ring cannot be subject to collision, impact or collision with other magnetic fields.Remove from the packaging 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 needle on the instrument panel through the road test. 8. Hub bearings equipped with ABS magnetic thrust rings. In order to determine which side of the thrust ring is installed, you can use a light thing close to the edge of the bearing, and the magnetic force generated by the bearing will attract it.When installing, point one side of the magnetic thrust ring inside, facing the sensitive components of the ABS.Note: Incorrect installation may cause the function of the brake system to fail. 9. Many bearings are sealed, and such bearings do not need to be greased during their entire life.Other unsealed bearings, such as double-row tapered roller bearings, must be greased and lubricated during installation.Due to the different sizes of the inner cavities of the bearings, it is difficult to determine how much grease is added. The most important thing is to ensure that there is grease in the bearing. If there is too much grease, when the bearing rotates, the excess grease will ooze out.General experience: During installation, the total amount of grease should account for 50% of the bearing clearance. 10. When installing lock nuts, the torque varies greatly due to the different bearing types and bearing housings. Note to refer to the relevant instructions.

The closed forging process of the outer ring of automobile wheel rim includes cutting: the blank is made by sawing process, heating: the blank is heated to 1100~1400℃, upsetting: the blank is upsetting on the upsetting equipment to obtain a drum-shaped blank, pre-forging: The drum-shaped blank is made of pre-forged parts through the pre-forged die, precision forging: The pre-forged parts are made of forgings through precision forging dies and hot forging machines. The sawing process can better control the accuracy of the blank blank, reduce the burrs of the forgings, make the quality difference between the blank and the final forging smaller, and reduce the loss of raw materials. The forging process adopts a 2500-ton hot die forging press, which is formed by a cavity forging process. The weight difference between the blank and the forging is controlled within 0.3% during the blanking period, which controls the cutting accuracy, reduces the generation of burrs in the forging, and reduces the waste of raw materials. When designing the forging die, the upper die is designed as a punch, and the lower die extends to the periphery of the cavity, and the guide hole is designed.

There are many kinds of wheels according to the diameter, and there are also many kinds according to the width.Then, many models can be divided into different diameters, different widths, and different materials.Some car owners think that the original tires are not advanced enough and want to upgrade. They often widen, reduce the flat ratio, increase the diameter, and change the material. At this time, if you have to change the wheels, it is called a modified wheel. 1. What types of wheels are there? According to the surface treatment process of the wheel rim , different methods will be adopted, which can be roughly divided into two types: paint and electroplating. 1. Painted wheels are moderately priced and durable. The wheels of ordinary models are less considered in appearance, and good heat dissipation is a basic requirement. The process basically adopts paint treatment, that is, first spraying and then electric baking. The cost is relatively economical, the color is beautiful, and the retention time is long. Even if the vehicle is scrapped, the color of the wheels remains the same. The surface treatment technology of the wheels of many large-scale models is paint, and some fashion-forward and dynamic color wheels also use paint technology.Such wheels are moderately priced and have complete specifications. 2. The price difference between electroplated wheels is large. Electroplating wheels are divided into silver plating, electroplating and pure electroplating.Although the color of electroplated silver and electroplated wheels is bright and vivid, the retention time is short, so the price is relatively cheap, and it is liked by many young people who pursue freshness. Pure electroplated wheels, the color is maintained for a long time, which can be said to be of high quality and high price.Some high-end cars will be equipped with pure electroplated wheels as standard in the original factory. Wheels can be divided into two categories according to the material: steel wheels and alloy wheels. 3. The most important advantage of steel wheels is that the manufacturing process is simple, the cost is relatively low, and the ability to resist metal fatigue is very strong, which is what we commonly call cheap and strong.However, the disadvantages of steel wheels are relatively prominent, that is, the appearance is not beautiful enough, the weight is large, the inertial resistance is large, the heat dissipation is relatively poor, and it is very easy to rust. 4. Alloy wheels have light weight, low inertial resistance, high production accuracy, small deformation and low inertial resistance when rotating at high speed, which is conducive to improving the straight-line driving performance of the car and reducing the rolling resistance of the tires, thereby reducing fuel consumption. The thermal conductivity of the alloy material is about three times that of steel, and the heat dissipation is good. It can play a certain role in the thermal attenuation of the vehicle's brake system, tires and brake system. At present, the alloy wheels of original cars on the market are mainly aluminum alloy. Of course, many modified wheels will choose chromium, titanium and other elements as basic materials in order to meet certain special requirements and visual improvement. However, compared with steel wheels, the price of alloy wheels is much more expensive, so often in many low-end original cars, steel wheels will appear on low-end models, while alloy wheels are standard for high-end models.

The wheel rim, also known as the hub, is a barrel-shaped metal part. The center of the tire is mounted on the shaft. The decorative cover of the wheel is generally fixed in the center of the wheel to beautify the appearance of the wheel and protect the wheel and the central rim. At present, part of the structure of the decorative cover of the wheel is directly fixed and welded to the wheel. Today we will show you the benefits of using the aluminum alloy wheels . The connection will damage the surface finish of the wheel, the operation is more complicated, and the quality of the connection is not guaranteed; the other part is the rim decorative cover, the mounting hole on therim is fixed to the rim, for example, the decorative cover is mounted on the rim surface of the wheel through a pawl. Although the operation is simple, the installation size cannot be adjusted. The aluminum alloy wheel rim includes arim body, the middle of the rim body is provided with a mounting groove, the bottom of the mounting groove is provided with a central hole connected to the axle socket, the edge of the mounting groove is provided with a stepped hole, and the step hole of the decorative cover is provided with a step hole. The center hole of therim body is provided with a snap ring close to the outer surface of the rim. The decorative cover includes a decorative surface that matches the external shape of therim body and a mounting surface located inside the rim body. The outer side of the lower end of the buckle is provided with a protrusion, and the inner side of the lower end of the buckle is provided with an adjustment groove corresponding to the protrusion.