Automatic Gearboxes Explained

Automatic gearboxes provide a wide range of output speeds by allowing the engine to operate within a narrow range of speeds. These gearboxes make use of a device named planetary gear set to achieve automation. For achieving different speeds gear ratio needs to be changed. Without proper gear ration engine screams out and wears out finally, making your vehicle dysfunctional. While manual gearboxes make use of different sets of gears to achieve different gear ratios, the automatic ones produce different gear ratios by using the same set of gears.

How do automatic gearboxes work?


Present day gearboxes in cars and 4×4 vehicles that work automatically consist of epicyclical gear train. The epicyclical gear train consists of four to five gear rings such as a sun gear, a ring gear and two to three planetary gear. While sun gear and ring gear work as central and outermost gears respectively, the planetary gears revolve in between these two. The transmission of gears is achieved through fluid drive. The whole concept is called torque conversion.

Transmission and speed

To achieve a speed increase the central ring is locked, planetary rings are driven and the output is taken from the outer ring. To achieve a decrease in speed, the outer ring is locked and the central gear is driven. As above the planetary rings are driven in the same way. To achieve a speed in reverse the power input is fed to the central gear, the external gear is driven and the planetary rings are locked. A direct drive without change in speed is achieved through locking of central gear and external gear. The whole unit works as one to achieve a single direction of rotation. Most of gearboxes have three forward speeds and they make use two sets of planetary gears. The whole locking mechanism is achieved through hydraulic pressure by operating multi-plate clutches. For changing down top acceleration knockdown mechanism is used.

How automatic gearboxes are different from manual ones?

You need to shift the gears as per the speed in manual gearboxes, while in automatic ones; you don’t need to change gears. In manual gearboxes, a driver has to give inputs constantly. In automatic ones, all the functions occur without any input from the driver. The mechanism utilized by manual gearboxes is easy in comparison to the automatic ones. Any auto mechanic can detect problems with the manual gearboxes. But for automatic gearboxes you need to go to specialised mechanics.

What problems you may have with automatic gears?

Delay of response

Delay of response is a transmission based problem that arise at times when you are about to shift in to drive and you feel a delay in gear engage.

Buzzing noise

You can hear a humming sound during gear transmission with gearboxes that work automatically.

Leakage of automatic transmission fluid

Automatic transmission fluid is the life-blood of the gearboxes as it works as a lubricant. Transmission of gear system breaks down with the leakage of this fluid.

Burning smell

Overheating of transmission fluid may cause your breaking system breakdown.

Gear slipping

It is a common problem in which transmission fails and the gear system goes back to neutral.

Dragging clutch, neutral transmission noise and many other problems are there related to automatic gearboxes.

When you are looking for spare car parts you can make a request on and it will automatically be sent out to all the car breakers and dismantlers throughout Ireland.

Main problems with gearboxes

A car is a machine and just like any other, it’s also prone to problems. The car transmission system has a very complex mechanism which translates to higher chances of troubles and glitches, especially gearbox problems. These problems can be a nightmare, as they can ground your car, until they are completely fixed. Since the working of car gearboxes is very complex, any problem should be left to professionals as you may complicate things further by fixing it on your own. But, some basic knowledge about transmission can help you troubleshoot these problems. This article highlights the common encountered transmission problems, along with their symptoms. When buying used cars in NI or in any location ensure proper checks are carried out like mileage check and previous owner inquiries. A full HPI check is the most comprehensive vehicle check you could do to ensure peace of mind before buying. If you are on the market for used car parts you can place a request on

Fluid Leak

Most gearbox troubles are often associated with fluid leakage problems. Transmission fluid is used to lubricate the moving components of the gearbox. It also serves as a heat sink that absorbs the heat energy generated in the transmission system. Fluid leak can be triggered by several factors such as poor installation and broken seal. It often starts, either if the filler tube becomes loose or if the pan gasket becomes defective. The car transmission system is generally exposed to high temperatures, which makes it prone to a lot of tear and wear. This can lead to an eventual breakdown, thereby causing the fluid to leak.

Gear Slipping

This is another common car gearbox problem. Slipping symptoms include:

– Transmission delay: Delayed response in the car’s acceleration even after pressing the gas.

– High RPM: Abnormal increase in revolutions per minute of the engine.

– Abrupt downshifting: When you are driving on a high gear at a constant speed and the car abruptly shifts to a low gear without changing speeds, the car may be experiencing a slipping problem.

This problem can be attributed to incorrect fluid levels, broken bands or gears or even internal clutch. To avoid this problem, ensure you regularly check the transmission fluid levels.

Surging of Transmission

Abnormal jerking movements while changing gears is an indicator of transmission surge. When the transmission engages or disengages, a defective gearbox doesn’t smoothly shift into the new gear, and the car engine delays to adjust to the new resistance offered by the car wheels. This transmission problem is often experienced at lower gears.


If your temperature indicator shows a high temperature but you find that your car radiator is just fine, then there is a possibility that the car has a gearbox problem. Overheating of the car transmission system is often caused by clogged fluid cooler lines. It can also be caused by a drop in the fluid levels or malfunctioning of the oil pump. Damage to the fluid pump may also lead to overheating of the gearbox.


Due to prolonged tear and wear of gears or low levels of transmission fluids, knocking noise might be heard. This indicates an imminent transmission failure.

These were some of the most common problems in the car gearbox. If you notice any of these symptoms, visit a repair shop immediately. Further delay in doing so, would ultimately result in very costly repairs. Find car parts in Northern Ireland or anywhere in Ireland on Everything Motoring.

Repair or Replace

Gearbox repairs usually involve some sort of problem for the mechanic diagnosing and fixing the issue. There are a variety of common issues that consistently arise that leave the repairer debating on whether it would be more cost effective to get a replacement car part from a car breakers or dismantlers yard. Find the exact year and model of vehicle can sometimes prove difficult as different models of car will sometimes have different gearboxes and the part number may not match that of the vehicle being fixed.

If you do decide it would be best to get a replacement gearbox instead of banging your head against the wall repairing the existing one, the next step is finding its replacement.

Although there are many car parts websites in Ireland, many of the car dismantlers in Northern Ireland and car breakers have been reluctant to advertise all the available parts online due to the time it would take to catalogue all the different component parts . Irish motoring website Everything Motoring Ireland have helped solve this by giving dealers the option of advertising either the whole car for breaking or the individual parts. This allows the car dismantlers more flexibility in how they get their available used parts in front of potential buyers. If they have the resources and time to put all of the parts online they can do it or alternatively they can just put the car itself online and let potential buyers know which parts of the car are available.

Signs that a Car Clutch Needs Replaced

If you are a car owner, one of the things you will realize is that the clutch is one of the most important components of the car. Making sure that it’s always in good condition goes a long way in ensuring that you get the most out of the car. Making a point of not neglecting the clutch will also reduce the chances of other parts of the car becoming damaged. If your cars is due an mot in ni be sure to put it through before expiry to make sure you stay road safe. Remember, the clutch usually acts as the intermediary between the engine and the gearbox. If it becomes damaged, it has the potential to damage both of these parts, and the consequent cost of repair is likely to become very high. Owners of used cars have several options when it comes to buying a new clutch or getting it repaired.

In order for you to make sure that this does not become a big problem for you, you will need to maintain situational awareness regarding the quality of the clutch. This can be done by understanding the signs of possible clutch failure, and having the problem sorted out as soon as you realize that there is a problem. Some of the common signs include:

Having more difficulty engaging the gears

When the clutch has problems, the commonest manifestations finding that the engagement of gears becomes very difficult. This is a problem that will become apparent when you are driving a manual transmission car, but cars with automatic transmission can also be affected.

Having the car rev without moving

With more sudden and severe damage to the clutch, you will notice that the car will not be able to move forward or back despite engaging gears, and even if the engine is revving. The latter usually means that the connection between the engine and the gearbox is faulty, which will manifest as inability of the power to be transmitted from the engine to the wheels. Since the car will not be able to move, you will often need a towing service to move the car to a garage.

You will notice a grinding sound when the gears are changing. If mechanical work is not your forte it may be better to leave into a car repair garage.

Another typical sign that the clutch has problems is when you notice that the process of gear change becomes a lot more noisy than usual. The typical sound usually has a grinding quality about it, and is usually a sign that there is a lot of friction between the clutch and the gearbox. Of course, there could be other parts of the transmission that are faulty and which cause this sign, but the commonest is a failing clutch. Depending on the level of damage it maybe possible to weld the part to repair it. Check out and read their guide on auto restoration and welding.

Reduced power output

A more nonspecific sign of clutch damage is reduced power output by the engine. For instance, you may find that the car accelerates much less quickly than it used to. A clutch problem could result in less efficient transmission of power from the engine to the gearbox, resulting in this problem.

These are just some of the signs that could mean that your car’s clutch has problems. Paying attention to them and making sure that the issue is addressed as soon as you find that there are such problems will be cheaper for you in the long run, and will also keep your car in better shape overall. When it comes to find that new clutch go to Cars Parts NI who have thousands of car parts to choose from.

What is the Best Type of Car Gearbox?

When it comes time for you to choose a new car, you want to be sure to keep in mind which of the types of car gearbox will work best for you. With the variety of car gearboxes available these days, it can be difficult to figure out which one is the right choice for you. The general breakdown of gearboxes is between automatic and manual. The automatic is where all of the innovative changes have begun to take shape, whereas, the manual gearbox has remained pretty standard. Hopefully, with this article, we will be able to help you choose which one is the best type of car gearbox for you.

Perhaps the simplest of all the types of car gearbox is the traditional format. This feature allows the car to decide when it needs to change gears and enables it to complete the change without any work for you. This means that the driver doesn’t have to worry about braking or shifting to change. The traditional format does also include a manual handle just in case a driver feels as if they need to change hears but the car was unable to sense it. This type of car gearbox is still fairly common and can be found in some BMWs, Land Rovers, and Jaguars.

Another one of the types of car gearbox available is the continuously variable transmission, otherwise known as just CVT. This is one of the more modern and efficient gearboxes available today. It works by having two pointy cones facing each other with a belt suspended in between. As the cones move in response to what the car is telling it, the belt moves as well, which signals the gear change. While this may be one of the most effective types of car gearbox, it can get a little bit noisy since it stays at the same pitch instead of fluctuating with the car’s movements.

Another of the more popular types of car gearbox available is the dual-clutch. Obviously this means that the car holds two different clutches. To make it easier on you though, they are both operated by the car’s system. This works by creating one clutch to work with the even gears and the other one to work with the odd gears. By doing this, the car is easily able to switch from one gear to the next. This provides a seamless ride as well as higher fuel efficiency for drivers. The ability for the car to switch gears on its own is also enhanced by the fact that it is shown to be able to change gears faster than a person can.

The Automated manual is yet another of the various types of car gearbox on the market today. This is similar to the standard manual gearbox except that all of the necessary changes in gear and processed and performed by the vehicle and computer within it. This is a good combination of the type main types of car gearbox; automatic and manual. However, there are still some downsides. One of these is that the ride can get jerky while the car is switching from gear to gear. Because of that, the second problem, which is speed, arises. It is difficult to go a speed that you are comfortable with when the car is jerking you around. This model is commonly available in VWs.

If none of the automatic car gearboxes seems like the best fit for you, you still have the option of going with a standard manual. While it can take someone new a little while to learn how to drive, most people say that once you figure it out, it’s like riding a bike. This type requires you to use a manual gearshift to change a car from one gear to another.  The driver must also be able to multitask as it requires you to break and accelerate at varying points in the gear change process. A similar type of system of gear technology is now being used in uk drones which are now becoming a lot easier to fly as a result of this.

Regardless of your preference for cars, we hope that you are able to find the car gearbox that’s best for you and your needs. Whether your focus is on efficiency and gas or speed and ease, there is an option available to you.