The Wrong Way of Lubricating the Cross Universal Joint

Some automobile maintenance personnel pour the melted butter into the universal joint cross or make it reach the specified lubrication part. Due to the characteristics of the butter itself, the effective lubrication of the place is not achieved, which is caused by the characteristics of ordinary butter.

However, from the analysis of the physical and chemical composition of the butter itself, it is incorrect to use the butter in the cross joint of the car. The specific reasons can be analyzed as follows:

In general automobile maintenance manuals, it is clearly stipulated that the key teeth and intermediate bearings of the transmission shaft telescopic sleeve use calcium-based grease, and the cross needle roller bearings and the intermediate bearings of the rear axle transmission shaft of the three-axle drive car use gear oil.

However, in actual work, because there is no filling equipment, some repairers mistakenly lubricate the cross shaft needle roller bearings with calcium-based grease for the sake of convenience, causing a large number of premature cross bearings to be damaged.

Since the gear oil filling nozzle of the universal joint cross shaft is a very ordinary grease nipple, it often causes a misunderstanding. In fact, grease cannot be filled on the needle bearing. Because of the high viscosity of butter, when grease is added to the inner cavity of the cross shaft through the oil nozzle with a grease gun, the resistance of the butter into the narrow inner oil groove oil passage is very large. At this time, the butter will overflow by pressing the pressure relief valve opposite the oil nozzle. The repairman mistakenly believes that the bearing has been filled with oil. In fact, not only can the butter not enter between the needle rollers, but it is also difficult to reach the end face of the cross journal.

Therefore, the wrong practice of using butter instead of gear oil to lubricate the custom universal joints cross shaft should be changed, and gear oil should be filled with gear oil pressure gun.