All You Need to Know About Different Types of Gearbox
The gearbox is a crucial part of the car. A gearbox allows power to be sent to the wheels from the engine. As time has gone on, more types of gearbox have been developed and introduced. Now there are several types of gearbox to choose from. However, which one is better? This article discusses types of gearbox and their pros and cons.
In this guide:
- Different Types of Gearbox
- Different Types of Automatic Gearbox
Different Types of Gearbox
Every car has a critical part named the gearbox. Central to its makeup, a gearbox allows power to send from the engine to the wheels and gives a key access point between the machine and driver. More types of gearbox have been produced and introduced as time has gone on. There are several types of gearbox to choose from today, though how are they different? Following are some of the world spread types of gearbox available and how they are different from each other. Let’s get to them.
The manual types of gearbox could be seen as the classic. It involves a stick that allows the driver to select the gear they want, while a pedal is used to disengage the clutch, allowing you to change gears. This setup gives the driver complete control over the gears, allowing them to either drop a gear to make a quicker process or choose a higher gear to preserve fuel. Manual transmission is widespread in older models of cars.
Automatic transmission has been around in different forms for nearly a century now. They invented these types of gearbox in the 1920s, but Cadillac and Oldsmobile popularized them in the 1940s. The concept of removing one of driving’s most challenging skills is one that’s remained attractive right up to today.
Historically, automatic transmissions have been there to take the load off, removing the need for a driver to press the clutch, select the gear, release the clutch, and in vehicles without synchromesh, to match the engine transmission revs to make sure a clean change. Instead, drivers can select Drive and set off without a care.
In recent years, they’ve also become the choice of transmission for serious performance machines, able to deal with immense power more safely and efficiently than a human driver could. However, not all automatic types of gearbox are the same, so what are the different types? How do they operate, and is there a difference to the user?
Different Types of Automatic Gearbox
There are four available types of automatic gearbox available in the market, including:
- Torque converter,
- Dual-clutch transmission,
- Continuously variable transmission,
- Single-clutch transmission.
Let’s take a closer look at them:
The torque converter or traditional automatic is the oldest and classic example of an automatic. For the last century, a torque converter automatic was near enough, the only option you had.
Rather than a clutch pedal to release the gearbox’s engine when switching gears, a torque converter drives fluid around a sealed case known as an impeller. It transfers energy from the engine into the liquid, which then goes to the output shaft.
These gearboxes use a liquid coupling known as a torque converter, which works as a link between the gearbox and the engine. This torque converter enables the slippage of a clutch with no risk of components wearing out. It also has no concerns coping with severe amounts of power, significant for new performance cars.
Early torque converter automatics had some pros and cons. The torque converter’s fluid nature with no reliable connection between engine and gearbox is combined with a severe lack of gears, usually three or four but often as few as two, meaning that efficiency was somewhat lacking.
They are the most comfortable and most reliable kind of automatic transmission on the plus side. A torque converter’s benefit is that it allows for smooth acceleration at lower speeds and good responsiveness at lower revs.
In new torque converter autos, these problems have been almost ironed out. The current torque converter is one of the best transmissions you can buy, capable of providing super-smooth shifts when you’re just bumbling on or razor-sharp ones when you put your foot down.
A mechanical lock employs when the engine and gearbox are running simultaneously, reducing losses through the transmission. Modern auto boxes can also have as many as eight gears, helping economy and performance.
You’ll find the modern torque converter in many cars, from small economy cars to the most expensive and powerful machines on the market. Now, there’s no disadvantage to ordering one unless, of course, you prefer the involvement of a manual gearbox.
A dual-clutch transmission (DCT) uses two clutches. In its most basic configuration, meaning there are different clutch systems for both the odd and even-numbered gears and the two hand over between each other for rifle-quick gear shifts.
It works by providing one of the gearboxes to pre-select the next gear before changing. Because of this, gearshifts are smoother and faster than with other automatic boxes.
The Volkswagen was the first to put a dual-clutch box into a production car on the Golf R32. From there, it made its path across performance vehicles to become the automatic transmission of choice for all Volkswagen cars; you’ll find it on everything from minis to supercars.
Dual-clutch boxes are very fast to change under pressure, and the way power is passed within clutches means there’s little to no reduction in intensity as the gears are changed. They can also be smooth, making for comfortable and steady progress. Economic and performance are not poorly affected and can even be better than their manual counterparts.
That said, dual-clutch transmissions can hurt from doubt. The gearbox’s electronic controller has to foretell what the driver will do and respond, respectively, and it doesn’t regularly get it right. It’s most evident in stop-start traffic, where the dual-clutch box can be hesitant and pulling away from a barely-stopped place, such as at a roundabout.
Dual-clutch transmissions can also be weak; early Volkswagen DSG boxes have a relatively high failure rate, as do other, more modern boxes such as Ford’s Powershift.
Continuously Variable Transmission
The continuously variable transmission (CVT) is a gearbox that is much-used but also much-criticized too. The continuously variable transmission is an exciting kind of automatic gearbox.
It’s fascinating that it doesn’t have gears; instead, it uses a single infinitely variable ratio to give theoretically any number of gears. It allows the engine speed to be altered at will to allow for maximum fuel saving, improved performance, or a mix of both.
It utilizes a cone shape with a circle around that and another axle. The bar can then be moved up and down the cone and alter its length, which, in turn, changes the gear ratio. It, therefore, allows infinitely variable rates between the top and bottom of the cone.
The problem with CVT is that acceleration often feels very strange, a rather odd, disconnected feel, compared with a regular automatic. It’s like a vehicle is pulling against a rubber band and is often followed by a droning speedup noise.
CVT types of gearbox tend to send the engine’s revs spiraling every time the driver puts their foot down, leading to an unpleasant rubber-band effect as the road speed catches up with the engine speed.
Some manufacturers have attempted to get about this by engineering in steps to their CVTs, typically shows where the transmission will hold its representation of gear and simulate a box with stepped ratios. It can make the drivetrain feel a little less unnatural but somewhat moots the point of having infinitely variable rates in the first place.
CVT gearboxes do have running losses, but the ability to run the engine at its most suitable speed, rather than whichever gear is closest, meaning they can be very efficient. CVTs are very common for use in hybrid vehicles.
Their smooth nature gives them more natural to use when switching between electric and petrol power. They assist in keeping the engine at its optimum point for recharging the car’s internal battery.
Single-clutch transmissions or automated manuals leave the existing manual clutch and gearbox systems in place and merely robotize the action. Essentially single-clutch transmission automatics are manual transmissions that shift automatically. Because of this, they highlight a standard clutch that disengages the engine when switching gears.
Though uncomplicated in theory, in reality, single-clutch transmissions haven’t shown that popular. This transmission is fading out of use but remains in position on cheap cars and small automatics. It’s the shortest, lightest, and most affordable way to get an automatic into a vehicle but has several disadvantages.
The pros are, as mentioned, lightweight and low cost. These gearboxes are very simple and efficient and don’t add many parts to the car.
On the downside, their simple nature doesn’t operate very well. Humans can shift gear with a single clutch because we know what we’re doing before we do it, robots have to catch up, and the resulting gearshifts are low, jerky, and extremely slow. It’s usually suggested to avoid an automated manual gearbox if you can.
There are several types of gearbox to choose from today, though how are they different? The manual types of gearbox could be seen as the classic. There are four automatic gearbox types, including the torque converter, dual-clutch transmission, continuously variable transmission, and single-clutch transmission. This article covers all available types of gearbox in the market and discusses the pros and cons of using each one.