Transmission is one of many components that make up a car's drivetrain, or powertrain, which includes the engine, driveshafts, and differentials. A car's transmission provides a car with speed and torque which is what allows the car to go different speeds. There are two types of transmission found in cars: manual and automatic. Although they perform the same function, each works differently and has a few different parts. Therefore, we will look at each one separately.
Manual Transmission
* The transmission is connected to the engine through the clutch. You press down on the clutch pedal when you shift gears.
* The clutch is connected to the input shaft which moves at the same speed as the engine.
** The input shaft is also connected to the layshaft. The layshaft has different gears on it. These are the gears you are moving when you shift gears. When you change gears, you change your speed.
* There is also an output shaft which connects to the differential. The differential is connected to your wheels.
* Your gearshift controls three rods. Every time you shift gears, these rods pull the gear back allowing the gear to turn.
** However, when you want to go in reverse, the gears will move in the opposite direction. The idler gear will make sure your car never goes in reverse when driving forward.
** Synchronizers are located between a gear collar and gear teeth to prevent grinding when you shift gears. If you do hear grinding, there may be a problem with the synchronizers.
Automatic Transmission
* Unlike manual transmission, the gears in automatic transmission are never physically moved. They are continually engaged in the planetary gear sets. It is made up of the sun gear, a ring gear, and two planet gears.
* Another component is the hydraulic system. Transmission fluid is sent by an oil pump through a valve body.
** The valve body controls clutch packs and break bands, which in turn, control the planetary gear set.
* Seals and gasket prevent any fluids or oil from leaking.
* A torque converter acts like a clutch for automatic transmission. It allows your engine to keep running even when the car has stopped.
* Today, cars have an internal computer which monitors vehicle speed, engine speed, throttle position, and much more. The computer sends signals to a solenoid pack which determines when your car needs to shift.
** Cars that don't use computers, have a governor and modulator, or throttle cable, which have inputs to tell the transmission when to shift.
