This paper takes a review of fretting phenomenon on splines of the engaging gears and corresponding splines on shaft of automotive transmission and how it leads to failure of other components in the gearbox.
Fretting is a special wear process which occurs at the contact area of two mating metal surfaces when subject to minute relative oscillating motion under vibration. In automotive gearbox, which is subjected to torsional vibrations of the powertrain, the splines of engaging gears and corresponding shaft may experience fretting, especially when the subject gear pair is not engaged. The wear debris formed under fretting process when oxidizes becomes very hard and more abrasive than base metal. These oxidized wear particles when comes in mesh contact with nearby components like bearings, gears etc. may damage these parts during operation and eventually lead to failure.
In this paper, a case study is presented wherein fretting has been identified as the root cause of failures of some child parts in a gearbox. A parametric study was carried out, evaluating design and operational parameters to identify the causes of fretting and their relative impact on gearbox durability, through rig testing. Corrective action and their correlation in addressing the failures of other child parts was further proved though rig testing.