When the transmission fails on a car, the car becomes practically useless because the transmission is responsible for changing the gears on the car, which in turn provides the power to the wheels to move it forward. Transmissions are, therefore, essential to a car's basic functioning, whether or not the car operates on an automatic or manual method of gear shifting.
Transmissions use a special fluid called ATF to make sure the parts inside the transmission are constantly cooled and lubricated. The parts in the transmission help to let the car shift its gears to vary the speed. If the fluid isn't replaced, this can lead to a loss in proper acceleration, the driver could have issues with shifting the gears or the transmission could fail and have to be replaced.
Because of this, car maintenance guides recommend that car owners replace their ATF fluid regularly using their owner manuals. If they begin to notice issues with their transmission, they should get their car serviced right away to try to address the problem before it's too late. A transmission is an essential part to the car, and whether they operate as a manual or automatic transmission, they tend to be very complicated pieces of machinery that require a trained professional to service.