Do not use the grease randomly

Some mechanic will add grease on the cylinder gasket when installing the cylinder gasket, they believe that this can increase the sealing of the diesel engine, which will affect the working performance of the diesel engine. In order to tighten the nuts easily and prevent corrosion, many mechanic applied oil on the bolts and nuts, which is also a wrong practice. Because after the tire nut is tightened, there is a self-locking feature between the threads. Because the helix angle of thread is less than the equivalent friction angle between threads. In a given bolt connection, the helix angle is a certain value, and the equivalent friction angle changes with the friction state between threads. Obviously, the equivalent friction angle between threads decreases after adding oil, and the self-locking performance of bolt connection becomes worse. Therefore, do not apply grease or oil on the bolts and nuts of the tire. Doing so will loosen the nuts and even cause accidents.