A Differential Has 3 Jobs.

  • Aims the engine power at the wheels
  • Acts as the final gear reduction slowing rotational speed of the transmission one final time before it hits the wheels.
  • To transmit power to the wheels allowing them to spin at different speeds


A Differential is a device that splits engine torque two ways allowing each output to spin at different speeds.

Differentials are found on all modern cars and trucks, also in many all-wheel-drive vehicles. These all-wheel-drive vehicles need a differential between each set of drive wheels, and need one between the front and the back wheels as well, because the front wheels travel a different distance through a turn than the rear wheels.