In the general car repair manual are clearly defined: the drive shaft telescopic sleeve of the key and the middle bearing the use of calcium-based grease, cross-needle bearings and three-axle drive the rear axle drive axle bearing the use of gear oil. However, in the actual work, due to no filling equipment, some repair workers in order to facilitate the map, the wrong use of calcium-based grease lubrication cross shaft needle roller bearings, resulting in a large number of cross bearing premature damage. As the universal joint cross shaft injection gear oil mouth is a very common butter mouth, often give people a misunderstanding, in fact, butter is not filling the needle on the needle. Because the butter viscosity is large, when the butter gun through the nozzle to the cross shaft cavity plus butter, the butter into the narrow oil tank oil resistance is very large, then the pressure will be the top of the nozzle to open the nozzle opposite the overflow valve, which So that the repair workers mistakenly believe that the bearing has been filled with oil, in fact, not only can not enter the needle between the needle, that is, to achieve the cross-journal face is also more difficult. Therefore, it should be changed with butter instead of gear oil lubrication universal joint cross shaft error practice, but should use gear oil pressure gun filling gear oil.