What is an automobile transmission

A transmission in a car: how does it work and how important is it?

Since the transmission is one of the most important parts of a car, it can be assumed that all car owners know what a transmission is. At least they know how a gearbox works and what the difference between a manual and an automatic gearbox is. There are also many different types of gearboxes available today.

Contents overview

What is a gearbox

The transmission is an essential part of your car without which driving would not be possible. As part of the drive train, the transmission sits directly on the engine and converts the engine speed into torque, which drives the wheels.

The transmission is responsible for enabling efficient driving. By changing gears, which takes place either automatically or manually, you can ensure that the speed remains low, the engine is spared and fuel consumption is reduced. This also ensures that the motor is not overloaded.

Basically, a distinction is made between manual transmissions in cars, in which 5 or 6 gears can be changed manually, and automatic transmissions, which change gear fully automatically without the driver having to operate the gearshift.

This is how a transmission works

In a nutshell, the transmission works by transferring power from the engine to the wheels through the drive shaft and wheel axle, which allows you to drive the car. Changing gears changes the interaction between different gears inside the transmission. Different gear ratios are produced in this way. The power of the engine is converted by the transmission in such a way that it fits the respective driving situation.

The transmission passes this power on to the drive shafts that drive the wheels. For this reason, you will immediately notice if you shift into the wrong gear or accelerate too much when starting off. The transmission can only perform its tasks with the aid of the gears and gear ratios, which can be changed either automatically or manually by the driver.

In a vehicle with a manual gearbox, actuating the clutch bridges the connection between the engine and the gearbox so that you can shift into another gear. With an automatic transmission, this happens fully automatically without having to operate the clutch pedal.

You can check the service schedule for your car to find out when the transmission oil change is due. It is an integral part of a car's maintenance schedule. How often the oil in your transmission needs to be changed varies from car brand to car brand, but most manufacturers recommend changing the transmission oil after approximately 150,000 to 180,000 km. Even minor problems can cause major damage to the transmission, which is why you shouldn't take any unnecessary risk if you notice a problem with your transmission.

If you want to get a new car in the near future, then you should think in advance which type of transmission you want to choose. In this article you will find the most important information about gearboxes so that you can make the decision easier.

Manual transmission or automatic transmission

In a European comparison, German drivers tend to be more traditional and predominantly drive with a manual transmission. Autobutlers car mechanics estimate that around 65% to 70% of all German cars have a manual transmission.

If you buy a car with a manual gearbox, you can operate the controls yourself with the gear stick and guide the gearshift. Many car owners prefer to be in control and to be able to change gears. At the same time, one should also know that a manual transmission is cheaper than an automatic transmission for most cars in the long run.

The advantage of a car with an automatic transmission is that you can concentrate completely on driving and no longer have to change gears. On the one hand, this increases your driving comfort, but on the other hand, it is also faster in some situations, such as when approaching traffic lights or when turning. In addition, an automatic transmission is very convenient in traffic jams and stop-and-go traffic, as you do not have to concentrate on changing gears.

This is how an automatic transmission works

A "normal" automatic transmission is now electrically controlled and works via a hydraulic system. Since the gearbox is set up so that it shifts into a new gear when the revolutions increase enough, this also means that the fuel consumption is much better with an automatic gearbox. Because the transmission regulates consumption continuously and ensures that the correct gear is set.

As the name suggests, an automatic transmission shifts gears fully automaticallywithout the driver having to do this. The only settings that you have to consider as a driver are P for parking, R for reverse, N for neutral and D for drive, which is the driving gear.

This article will teach you more about how to drive with an automatic transmission.

Automatic transmissions are usually constructed in such a way that there is a large gear wheel in the middle of the transmission, which transmits the power from the engine. Distributed around this gear are various gears, which are known as planetary gear sets. They are of different sizes and can be connected or separated from each other. Another gear sits around these gears, which transfers the power from the planetary gear sets to the gears. A gear change takes place in a smooth transition between the various gears, which makes the driving experience more relaxed, as there is no jerking as if you had to change gears manually.

Many newer automobiles, such as Ford automobiles, have an automatic transmission output called a power shift. This can change gears even faster when accelerating. When you press the accelerator pedal, the power shift enables the car to pick up speed faster and change gears more easily.

In addition, there is also a so-called CVT (Continuous Variable Transmission), which is characterized by the fact that it only has a single chain that transmits the power from the engine to two pairs of friction disks. SO the pulleys are adjusted axially and the translation is infinitely variable.

It is also important to have your car's fully automatic transmission checked and serviced at all times to prevent damage and problems. Automatic transmissions wear more "directly" than manual transmissions, where the clutch wears the most. The fully automatic gearbox is cleaned during maintenance, which prevents other wear-related contamination from the gearbox oil.

What is a semi-automatic transmission

In the case of a semi-automatic transmission, the clutch is present in the car, but the driver does not have to operate the clutch and the clutch pedal is also not present. In a semi-automatic mode, a computer is responsible for changing gears automatically.

How a semi-automatic transmission works in practice varies from car to car. In some cars, the driver doesn't have to do anything to change gears and can just let the engine and electrics do the job.

In most cases, however, the driver himself has to tell the engine whether a gear needs to be changed. The driver has to move the gearshift lever in the desired direction and the electronics change gears. If the gears have to be changed while driving, this happens without the driver having to operate the clutch and engage the new gear. However, the driver still has to operate the gearshift lever. The gear change itself takes place in a so-called actuator, which is a drive element in gasoline engines.

From a purely financial perspective, buying a car with a semi-automatic transmission can be beneficial as it will require fewer repairs in the long run. If something in the fully automatic transmission is damaged, the mechanic has to remove the entire manual transmission, which can be very expensive. With the semi-automatic manual transmission, the car also has a clutch, which is the transmission part that wears out the fastest. In this case, however, this is an advantage, because the clutch is much cheaper to repair than the gearbox itself.

Cars from Peugeot, Citroën, Volkswagen, Audi, Škoda and Seat often have a semi-automatic transmission. The gears used vary greatly between the different car brands.

The most important facts about DSG gearboxes

A DSG transmission is a mixture of a manual and an automatic transmission, which enables fully automatic gear changes. With a DSG, power is transmitted via two clutches, which is where the name double clutch transmission comes from. The choice of gears is electronically controlled based on the engine speed, the driving speed and the behavior of the driver.

One of the greatest advantages of DSG transmissions is that they optimize fuel consumption as well as manual transmissions, but are as pleasant to drive as automatic transmissions. In addition, dual clutch transmissions have a longer service life and less wear and tear and are associated with lower manufacturing costs.

Since the DSG transmission was developed by Volkswagen in 2003, it is still installed in many cars from German car manufacturers, including cars from Audi, BMW and Mercedes-Benz. A disadvantage of the double clutch transmission is that you should always pay attention to the correct maintenance, because often with this type of transmission a transmission oil change is due every 60,000 km. If this is disregarded, increased wear and tear can result from dirt and dust deposits.

This is how a sequential transmission works

The sequential transmission is also classified between an automatic and manual transmission. You can set the gears manually and shift yourself, but the transmission itself works with an automatic, which is why it is often referred to as a semi-automatic.

As the name suggests, the gears on a sequential gearbox are arranged in a line instead of the normal H format. For this reason, you can only shift into the next higher or previous gear. All you have to do is tap the gear lever and the transmission will change gear.

A sequential transmission gives you the advantage of being able to shift between gears more quickly and increase speed more easily. Manual shifting gives drivers a new driving experience because they can control the car individually without having to concentrate on the shift. At the same time, they do not leave the gearshift completely to the automatic system. This type of transmission is installed in various Smart models, such as the Smart Fortwo.

This is the Active Shift Control

Only recently, Hyundai developed an improved version of the transmission control for hybrid cars. Hybrid cars are still relatively rare even now because they have both a gasoline engine and an electric motor. The biggest advantage of a hybrid car is that it uses the electric motor whenever the normal gasoline car has the highest fuel consumption, especially when starting and accelerating.

The so-called Active Shift Control improves fuel consumption, gear changes and the durability of the transmission even further. At the same time, this also improves the speed acceleration. This is guaranteed by the ASC, which is also known as Precise Shift Control. It optimizes the moment and the transfer of power to the wheels by making the gear change rate more effective.

The rate of gear changes is measured using a sensor that registers and synchronizes the revolutions of the electric motor in the transmission. As a result, the Active Shift Control intervenes when changing gears. The smoother gear change reduces energy losses by up to 30%. In addition, the duration of a gear change is reduced from around 500 milliseconds to just 350 milliseconds, which also reduces friction in the gearbox, which in turn increases durability.

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