Different Types of Car Transmissions

The car transmission is one of the most important components of your vehicle. The transmission (a.k.a. gearbox) is a mechanical machine controlling dual functionalities: managing the power generated from the car's engine (also called the powertrain) and transmitting it to the wheels, as needed.

In other words, it moves the power from the engine to the wheels. This transmission of power is done through a mechanical system of gears and gear trains. It is because of the car transmission system that the driver can apply power to the vehicle in a controlled manner, without which the car cannot function optimally.

To understand the role of the vehicle transmission system it's important to understand its functionality.

There are several gears in your vehicle (between 4-6) that determine the crankshaft revolution per minute (RPM). The gears have to be shifted depending on whether you need more or less power from the engine.

It is the transmission mechanism that allows the driver to change the gears and determine the amount of power that the engine needs to generate through combustion.

So, if your engine needs lower power and you are in a higher gear, then at this higher RPM, there is more fuel consumption and more than necessary stress on your engine.

Essentially, then, the lower gears of the gearbox give the necessary torque for acceleration, whereas the higher gears acquire high speeds by making use of the engine power more effectively.

There are primarily two types of transmission systems: Manual and Automatic. While manual transmissions have been here for a while, automatic transmissions are a true marvel of modern engineering.

Only as early as a decade ago, an automatic vehicle transmission system was a novelty for India, with only a handful of options in the mass-market cars. We have come a long way since, with almost all car makers in India almost all manufacturers having some sort of automatic gearbox option in their depository.

There are several types of gear transmissions available in cars, each with its unique set of advantages and disadvantages.

The automatic variant needs little driver intervention, whereas the stick-shift cars with manual transmissions need the driver to complete extra steps for the vehicle to function.

Depending on the driving style and the preference of the driver, one can opt for the most suitable car transmission. With that in mind, let’s take a look at the types of gears in cars:

Manual Transmission

Just as the title suggests, in a manual transmission, the driver has to manually change the gears according to the speed and power they want. For this, they should engage the clutch by pressing and releasing the foot pedal and shifting to the right gear ratio via the lever that allows them to change gears and regulate the torque.

When the clutch is pushed, the input shaft of the engine is disengaged during which the driver can increase or decrease the gear. Once the clutch pedal is released, the input shaft gets locked again.

Generally, a manual transmission will allow the driver to select any gear at a time as opposed to a sequential manual transmission that only enables shifting to the next higher or lower ratio.

The gear lever is usually mounted on the floor, but some cars also get a console-mounted (on the dashboard) or column-mount gear selector.

Depending on the engine capacity and the segment, modern cars come with five- or six-speed manual transmissions. Formerly, the cars came with three- or four-speed manuals, and some also comprised seven-speed manuals. The speeds are indicative of the gear ratio.

Torque Converter Automatic

Of the different types of transmission systems, the automatic ones offer a convenient driving experience by self-shifting the transmission without needing an intervention by the driver.

The torque converter transmission, in particular, employs a mechanism of advanced fluid coupling that boosts the torque generated by the engine to transmit power to the wheels. Although it is one of the oldest kinds of automatic transmission found in cars, it is widely regarded as a marvellous engineering feat.

Cars with a torque converter transmission don’t have the clutch pedal. Instead, the system functions via two turbines, where one is connected to the engine and the other to the transmission.

The hydraulic fluid between the two turbines transfers power from the turbine on the engine to the turbine on the transmission. This, in turn, propels the car’s movement.

It is easy to drive cars with torque converter transmissions as they give ample torque for smooth acceleration. Torque converters also have good fuel economy, but because there is complexity in designing them, they are costlier than their manual counterparts.

CVT Automatic

The continuously variable transmission (CVT), also called a pulley transmission or a step-less transmission, is an automatic gearbox that smoothly changes via a continuous range of gear ratios.

There are virtually infinite gear ratios on the CVT that can be altered on the go for a seamless driving experience. Interestingly, unlike other automatic transmissions, the CVT does not rely on torque but instead transfers power to the wheels by using infinite gear ratios.

This type of transmission system in a car uses four cones (pulleys) in their design. These pulleys are connected with rubber belts and dangled along two parallel axles. Then, to create the infinite ratios, the cones either go up-down, and the axles move closer and apart.

There are predefined steps (generally five or six) in modern CVTs to control the movement of the axles and the cones and to enable better control of the driver by ensuring smooth power delivery.

DCT Automatic

The dual-clutch transmission (DCT) is a kind of gearbox employing two distinct clutches for sets of odd or even gear ratios. The outer clutch that is larger drives even-numbered gears, whereas the inner clutch, which is smaller, drives odd-numbered gears.

As both of the alternate gear ratios (odd and even) can be selected beforehand (even when you are driving in any gear speed) without an interruption to the wheel’s torque distribution - the DCTs are the quickest road car transmissions.

There are two main types of DCTs:

Wet multi-plate clutches: uses oil cooling and is meant for engines that generate a high torque output (350 Nm or more).

Dry single-plate clutches: suitable for smaller engines that produce lower torque output (up to 250 Nm). Since there are no fluid pumpkin losses in the dry-clutch DCTs, these are comparatively more fuel-efficient.

**AMT **

AMT is an automated manual transmission, which is also known as an auto gear-shift transmission. Essentially, it is a manual gearbox comprising an electronically or hydraulically controlled actuator, which shifts gears automatically.

The transition of the gear depends on the speed of the vehicle and the throttle input. They are cheaper than conventional automatic transmissions. They are designed for driving convenience, but they don’t necessarily ensure a pleasurable driving experience.

This could be why AMTs are slow to react to the input of the throttle, especially when the driver forcefully presses the accelerator pedal.

Now that we have explored the varying types of gear transmission in cars let’s discover ways in which you can keep the transmission in a healthy condition for a long time.

Several concerns can impair the optimal functioning of your car’s transmission system. So, regardless of the transmission system in your car, it is important to take care of and maintain it properly. Here are some precautions that can be taken to keep your car’s transmission in good condition:

Schedule Routine Maintenance: To increase the life and ensure optimal performance of your vehicle, its maintenance must be scheduled at regular intervals. The transmission fluid should ideally be changed every 15,000 miles or once a year. With regular maintenance not only can you prevent unpleasant breakdowns but also enhance the performance and fuel efficiency of your vehicle.

Routinely Check the Transmission Fluids: Drivers/owners need to keep up with the transmission flushes. This is because transmission fluids lubricate moving parts, dissipate heat, and ensure smooth gear shifts. Conversely, low fluid levels only invite complications. It is advised to promptly address the problem of low transmission fluid and avoid driving if the fluid is below the recommended level.

Don’t Ride the Brake: Driving with your foot on the brake pedal stresses the transmission system of your car. This action generates excessive heat and leads to premature wear of the brake elements. Another tip is that when you have parked your car on an incline, you should engage the emergency brakes to reduce stress on the parking linkage.

Ensure a Well-Functioning Engine: The engine and the transmission system of the car work in unison, which means that impaired performance of one can adversely affect the other. This is why it is essential to regularly maintain the engine of your car to ensure it runs smoothly.

Stop Completely Before Shifting Gears: Whether you are driving an automatic or a manual, it is important to stop your car completely before shifting gears. The components of the transmission system can suffer significant wear if the gears are changed when the vehicle is still in motion.

Just as the transmission is an essential component of your car to get your vehicle running, comprehensive four-wheeler insurance is imperative for ensuring wholesome road safety.

A car insurance policy acts as a financial safety net in distressing times by compensating for third-party liabilities as well as damages sustained to one's own vehicle. You can also enhance basic insurance for four-wheelers by opting for add-ons based on your specific insurance needs.

Use a car insurance calculator to check how much premium is payable for the insurance on your car so you can drive in a worry-free manner.

What is a torque converter?

A torque converter employs automatic transmission mechanisms to transmit power from the engine to the crankshaft

How many kinds of automatic transmissions are there?

There are five types of automatic transmissions: CDT, AMT, CVT, Torque Converter, and iMT,

What are the advantages of automatic transmission?

Here are some of the key advantages of automatic transmission:

It is highly convenient in traffic by eliminating the need to continuously change gears

You need not worry about the clutch wear and tear

Since it accurately changes gears on your behalf, the stress on the engine is reduced