First of all we will start by knowing what an automobile transmission is. A transmission is a mechanical device which is used to transfer the power from the engine to the differential of the driving wheels.
A transmission is important because internal combustion engines have a very specific power band for specific revolutions per minute RPM ranges so the transmission is designed to keep the engine in it’s power band while giving the driver the ability to control or regulate the speed of the vehicle. Now we will look at the different types of transmission we have.
This is the most common type of automobile transmission. As the name suggests, the driver manually changes the gears using the clutch. There are three pedals in a vehicle with a manual transmission i.e the accelerator, the brake and the clutch pedals. when the driver wants to change the gears, he matches down the clutch fully which disengages the transmission from the engine to enable him change the gears and when the driver releases the clutch, the transmission is engaged to the engine again.
This type of transmission has advantages and disadvantages. one of the advantages of the manual transmission is that it is easy for car manufacturers to produce. Again it is light weight, it is fuel efficient, it is reliable, it keeps the driver alert and engaged and it is fun to drive.
The disadvantages of this type of transmission is that it is difficult to learn how to drive a manual transmission, and if driven wrongly can damage the clutch plate and the gearbox.
This is another type of automobile transmission and it is seen in most modern cars of today as a lot of manufacturers are doing away with the manual transmission. the very first automatic transmissions existed in the 1940s and then they were limited to just 3 gears unlike today when we have up to 10 speed Automatic gearboxes.
Automatic transmission works with a torque converter and a torque converter is a mechanical device that transfers engine power to the transmission using fluids i.e the transmission fluid.
The torque converter acts as a clutch but instead of two separate units, the torque converter is a single unit.
The advantages of the automatic transmission is that it is easy to operate, it can handle a lot of torque,and it is also reliable.
The disadvantages of this is that it is heavier, sometimes it shifts at its own pace unlike the manual that you can shift when you want to, it is not as fuel efficient as the manual transmission etc.
Continuously Variable Transmission (CVT)
This is the easiest form of automobile transmission. Unlike other transmissions, the CVT has pulleys and belts instead of gears through which the power is transmitted. CVT provides a smooth increase in power and that is why manufacturers limit it in such a way that it does not operate on a wide band to actually give the full experience of gear shifts.
The advantages of the CVT is that it has the smoothest operation so far, it is light weight, it is highly fuel efficient.
The disadvantages is that it produces a lot of noise, it is not exactly fun to drive, it cannot handle high torque.
Dual Clutch Transmission (DCT)
The easiest way is understand this type of automobile transmission is to look at the name which is almost self explanatory. It can be said to be the combination of two manual transmissions. Just as the name suggests, it has two clutches. One of then is connected to the gears with even numbers while the second clutch is connected to the gears with odd numbers.
In this type of transmission, when you’re on a particular gear, the next gear is preselected and already engaged. So when you shift up, the clutch connected to the gear you’re on releases while the other clutch engages and this happens smoothly and seamlessly.
Advantages of this transmission is that it is smooth, it provides faster shifts, and it is lighter than the normal automatic transmissions.
Disadvantages is that it is not as reliable or efficient as the automatic and it expensive for car manufacturers hence it’s not very common.
Automatic Manual Transmission/Auto Gear Shift
This type of automobile transmission is basically a manual transmission but the clutch is controlled electronically by an intelligent shift control actuator.
The advantages of this transmission is that it is simple to use, it is easy to manufacture, and the fuel efficiency matches that of the manual transmission.
The disadvantage of this type of transmission is that it is not smooth.
Sequential Manual Transmission (SMT)
This type of transmission has straight cut gears instead of little gears like other transmissions. This type of transmission is used in racecars and motorcycles. In this type of transmission you can only shift gears gradually.
They have three pedals just like the manual transmission. But In this type the clutch is only used to move the car from a total stop or from the first gear. You don’t need to match down the clutch to change gears unlike the manual transmission.
The advantages of this transmission is that it is really fast, it can handle huge power and it is light weight.
The disadvantages is that it it has a noisy operation, the noise, vibration and harshness levels are high (NVH) and hence cannot be used in normal passenger cars.