Couplings are used to join to power transmitting components. Couplings can be rigid or flexible. Rigid couplings do not allow any misalignment between the joining components. Whereas the flexible couplings used in an automotive are designed to permit some degree of misalignment to acclimatize change in positions of power transmitting shafts. Nonetheless Couplings are used to connect two axles, two components, or two shafts of differently manufactured components, to transfer the power even when shafts are not aligned properly. Although, advanced couplings performs the chore of reduce shocks while transmitting power from one shaft to another, to provide protection against overloading, to reduce vibrations in shafts, and to disconnect when needed or overloaded. In an automobile, high reliability of its mechanical components is crucial so as to avoid accidents or injuries. Coupling are the key components of an automobile. If a coupling fails to perform its task, the vehicle will not be ab...