Why can't molybdenum disulfide grease be used on vehicle wheel bearings?
November 11, 2021
The most obvious feature of molybdenum disulfide grease is that it is black in appearance, but it does not mean that black grease contains molybdenum disulfide, or it may be graphite-containing grease.
Grease containing molybdenum disulfide is generally used in heavy-duty and impact-loaded rolling bearings, especially in slow or vibrating parts, such as universal joints. If this kind of grease is used on high-speed bearings, "slip" problems will occur. Because the molybdenum-containing grease will reduce the friction coefficient, the ball cannot achieve full 360-degree rotation due to the reduced friction, which leads to wear spots, which causes the lubrication of the rolling bearing to fail and reduces the service life of the bearing. Therefore, grease containing molybdenum disulfide cannot be used for the lubrication of vehicle wheel bearings.
When lubricating automobile wheel bearings, most people are accustomed to using full-hub lubrication, that is, the cavity of the wheel hub and the inner and outer bearings are all filled with grease. This is not only useless, but also harmful. After the inner cavity of the wheel hub is filled with grease, it causes poor heat dissipation of the bearing and increases the resistance, which increases the temperature of the bearing and accelerates the deterioration of the grease. In addition, after the grease is heated and expanded, the oil seal will be broken, causing the grease to drip onto the brake pads, which will cause the brake to fail and cause an accident.
