Grease consists of the base oil, thickeners, and additives. Recently, it has been recognized that the quality of greases greatly affects the function of component parts. The grease used for a constant velocity joint, which is a component part in automotive powertrain systems needs to prevent flaking by the fatigue of joint component parts. Generally, such evaluations are done using durability tests with actual products. In this study,the quality engineering approach was used for product development. For the ideal function, it was considered that friction. should be consistent under various usage conditions. In other words, the ideal function follows the basic law of friction:friction is proportional to load. The following zero-point proportional equation was used : y=βM where y is load and M is fuction. Oscillation, friction and wear tester was used to measure friction. Frequency, stroke and temperature were compounded to be the noise factor. Control factors such as thickener,additive types and the amount of additives were assigned to an L18 orthogonal array. The optimum condition was determined with more emphasis on improving sensitivity.
