The propeller shaft is a part that transfers the force that went through the transmission to the final speed reducing part (rear axle). It is used for back-wheel moving cars and cars with T/C installed. The propeller shaft especially has to deal with high-speed rotation and torsion.   Therefore, it is highly related to the NVH of the car. In order to maintain active and inactive equilibrium, the design must consider its durability and self-vibration. It also needs perfect quality control.