How Does an Automatic Transmission Work?

If you drive an automatic car, you probably know that an automatic transmission doesn’t have a clutch pedal and doesn’t require manual gear changes. This is an excellent feat in technology and is actually pretty impressive. Automatic transmissions are getting better every year and many newer models can change gears seamlessly.

But have you ever wondered how automatic transmissions actually work? We’ll explain how in this blog.



Why do cars need an automatic transmission?

Without a transmission, cars would only be able to have one gear ratio which would only allow the car to travel at one speed. For example, if that speed was chosen to be 80 mph, you would need the gear to be in third. The car would barely accelerate to start, and once it hits 80 mph, the car would be screaming along in third gear.

So in order to make better use of the engine’s torque, the transmission uses gears, allowing it to operate at an appropriate speed.

How does it work?

Most commonly, an automatic transmission uses hydraulic power to shift gears which combines a torque or fluid coupling converter with gear sets that provide the desired range of gears for the vehicle. The engine is connected to the transmission with the torque converter and uses pressurised fluid to transfer power to the gears. This works in place of a manual friction clutch and allows the vehicle to stop without stalling.

The pump uses the power from the engine and converts it into transmission fluid that powers the turbine of the torque converter. This is able to transmit more power back to the turbine by increasing the power of the fluid. This then creates a vortex power rotation that spins the turbine and the attached central shaft. This power is transmitted from the shaft to the transmission’s first planetary gear set.

Automatic cars are great for a range of people, particularly those with disabilities, as you only need two usable limbs to drive. Not having a clutch or gear stick also means that the driver can give more attention to the roads.

Are you in need of automatic gearbox repairs in Bournemouth? Gearbox Specialists are here to help. We can provide a range of services for your gearbox and can replace or repair both manual and automatic transmissions. Visit our website to learn more or give us a call on 01202 309830.