Your automatic transmission transfers the power produced by the engine to the wheels via drive shafts and operates at extreme temperatures. It is these extreme temperatures along with general wear and tear that cause transmission fluid to become burnt and contaminated resulting in poor driveability and even slippage and no drive.
Automatic transmissions provide the level of precision needed to convert your engine’s power and torque to be redistributed for different purposes including reversing, towing trailers, highway driving and city driving. As your engine operates at various RPM (revolutions per minute) ranges, the transmission’s gear ratios are determined when certain gears are set in motion while other gears are made to remain stationary. Gears vary in size, positions and configuration to make the most of their interlocking teeth and allow the engine’s power to be directed to changing the direction the car moves in, synchronizing wheel rotations, the car’s weight distribution, and wheel-speed rotations.
Modern automatic transmissions are electronically controlled and have sensors within the transmission that monitor everything from vehicle speed to engine load and accelerator pedal position. The information these sensors provide is used by a computer to manage the gear shifting process.