Propeller Shaft, or Cardan shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement between them. In front-engine, rear-drive vehicles, a longer drive shaft is required to send power the length of the vehicle. Two forms dominate: The torque tube with a single universal joint and the more common Hotchkiss drive with two or more joints. A prop-shaft assembly consists of a propeller shaft, a slip joint and one or more universal joints. Signs of a propeller shaft failure includes vibrations while driving, noise coming from under the vehicle, clicking or knocking noise while driving etc.