A drivetrain or Transmission System, is the group of components that deliver mechanical power from the prime mover to the driven components. In automotive engineering, the drivetrain is the components of a motor vehicle that deliver power to the drive wheels. This excludes the engine or motor that generates the power. In marine applications, the drive shaft will drive a propeller, thruster, or waterjet rather than a drive axle, while the actual engine might be similar to an automotive engine. Other machinery, equipment and vehicles may also use a drivetrain to deliver power from the engine(s) to the driven components.
Rear axle with hypoid bevel gear final drive
Front wheel drive manual transaxle, showing the gearbox and final drive incorporated in the same housing
Construction vehicle drivetrain, with permanent all-wheel drive
A cutaway view of an automotive final drive unit, which contains the differential
A drive shaft, driveshaft, driving shaft, tailshaft, propeller shaft, or Cardan shaft is a component for transmitting mechanical power, torque, and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them.
Drive shaft with universal joints at each end and a spline in the centre
Škoda 422 rear axle, suspension and drive shaft on display at the Škoda Museum
A truck two section propeller shaft
The exposed drive shaft on BMW's first motorcycle, the R32