The principle of operation of DSG 7. Classic problems of the DSG transmission. Opinions and reviews

More recently, manufacturers have begun to actively install robotic gearboxes on cars instead of the usual and. As you know, a robot (RCPP) is mechanical transmission, in which automatic on / off is implemented, and without the participation of the driver, the selection and inclusion of the desired gear occurs.

In other words, a box - a robot is another type of automated transmission, while it is cheaper to manufacture, simpler in design, and provides high fuel efficiency.

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DSG robotic gearbox (DSG): what is it

So, in order to understand what a DSG is, you first need to consider the main types robotic boxes... In a nutshell, a robotic gearbox can be either a "single disk" robot (for example) or a preselective robotic gearbox with two clutches.

An ordinary robot, which has only one clutch, is similar in design to, while the engagement / disengagement of the clutch and the gears are controlled by the automatic (with the help of electric and hydraulic servos under the control of the ECU by the box).

This design is simple, the gearbox itself is quite reliable, however, when shifting gears, certain discomfort arises, the car "bites" its nose during intensive acceleration, a single-disk robot often delays the inclusion of a low and high gear, etc. Also, during operation, the clutch itself wears out quickly.

DSG box: device and principle of operation

In turn, DSG (Direct Shift Gearbox) is a direct shift gearbox developed by Volkswagen specialists. To put it simply, it's still the same manual transmission, but there are already two clutches.

Moreover, in such a box, two manual transmissions are combined in one case. Each of these conventional boxes has its own clutch disc. In this case, one box is responsible only for even transmissions, while the other for odd ones.

To switch up or down a step, the driver (in the case of a manual transmission) or ECU (in the case of a single-disk robot) disconnects the clutch disc from the flywheel, then engages the gear, and then reconnects the clutch disc. At the same time, it is not transmitted to the wheels until the clutch disc is connected to, the car noticeably loses in dynamics, and fuel consumption increases.

If we talk about DSG, for example, when a car with such a gearbox accelerates, the clutch of an odd row of gears is attached to the rotating flywheel, while the disc of the even row is in an open form. Further, while the car is accelerating in first gear, the ECU (mechatronic unit) gives the command to turn on the second on an even row.

Then, already at the moment of switching, the disc of the odd row is disconnected and the disc of the even row is turned on, while the next gear is similarly "prepared" for inclusion already in advance.

It turns out that if the car is moving, for example, in 2nd gear and then picks up speed, at the command of the ECU, 3rd gear will also be almost completely turned on. As a result, when the moment of upshifting comes, a full shift from 2nd to 3rd takes a fraction of a second, gears change very quickly, and the power flow is practically not interrupted at the moment of shifting.

This feature of work is clearly reflected in the name of this type of gearbox, since a box with two clutches is usually called preselective ( preselection and partial inclusion of the next higher or lower gear). As a result, the DSG transmission provides the high level of comfort inherent in automatic transmissions and variators, as well as the dynamics and fuel efficiency of traditional mechanics.

Types of DSG boxes: DSG-6 and DSG-7

DSG boxes are 6 and 7-speed. In this case, DSG 6 is "wet", while DSG 7 is "dry". The first version is designed for higher torque and is installed on powerful cars of the VAG concern. The DSG 7 version is installed on cars with less powerful internal combustion engines. The first to be developed was the six-speed DSG 6.

The clutch in such a box works in an oil bath. For this reason given type The checkpoint is called "wet". The disadvantages include the loss of power due to the large amount of oil and the need to implement its supply. The DSG7 version appeared later, it has a "dry" clutch. At the same time, the reliability of such a design has decreased, this type of gearbox has more problems and a shorter resource.

DSG resource and DSG boxes malfunctions

Let's start with the problems. Most often, the problem is expressed in the form of jolts when changing gears. The reason is too sharp clutch engagement, the car starts to twitch. Also, when shifting gears, there may be shocks, grinding noise. Another option may be the problem of loss of traction on a car with DSG, and right in motion.

As a rule, such malfunctions are more inherent in the DSG 7 with a dry clutch. Such a clutch is subject to rapid wear, in parallel, certain malfunctions are also given by Mechatronic (ECU box).

In the list of other problems associated with this type of gearbox, it is necessary to highlight the wear of the shaft sleeve, problems with the clutch release fork, electrical problems (contacts, failure of sensors, etc.). At the same time, it is important to understand that often for a non-warranty vehicle, DSG diagnostics and repair are expensive, and the cost of spare parts is also high.

If we talk about the resource, it should be noted that at the initial stage, no special problems with DSG 6 were observed on average, up to 150-200 thousand km. However, after many VAG models began to massively install DSG 7, the number of calls during the warranty period for runs of 60-80 thousand km. increased markedly.

As a result, the manufacturer launched a customer support program extending the full DSG 7 gearbox warranty to 5 years or 150,000 km, whichever comes first. Within the framework of this program, all repair work (up to complete replacement unit) were performed free of charge.

In the future, the program was curtailed, citing the fact that VAG engineers finalized the software for the control unit, made certain changes to the clutch design, that is, made DSG 7 more reliable.

One way or another, taking into account the information provided, it is quite logical to assume that the average resource of DSG 6 is about 200 thousand km, while for DSG 7 this figure is about 150 thousand km.

As you can see, a serviceable DSG gearbox is capable of providing good acceleration dynamics, comfort and fuel efficiency. In other words, the main tasks set for the developers in the conditions of the fuel crisis and tough environmental standards have been solved.

At the same time, the issue of resource and reliability was deliberately pushed into the background. In simple words, even a relatively reliable DSG 6 quickly replaced DSG 7. At the same time, given the obvious problems, VAG still preferred an expensive program warranty repairs and the active dissemination of information about the DSG7 modifications in order to increase its reliability to the banal abandonment of this checkpoint.

In other words, instead of going back to DSG 6 or the time-tested hydromechanical automatic transmission, the manufacturer continues to install DSG7 on many popular Volkswagen, Skoda, Audi, etc. models, claiming that the reliability of the box has improved significantly.

In practice, the feasibility of using DSG is questioned by many experienced car enthusiasts. Moreover, if we are talking about DSG 6, real mileage does not exceed the mark of 100 thousand km. and the checkpoint is working properly, then such a car can still be considered for purchase.

As for the DSG7, especially the first years of production, even if such a gearbox works normally, this does not mean that the residual resource is still large enough. In other words, you need to immediately prepare for a gearbox repair, and an expensive one.

We add that although there is nothing special to break in the box itself (shafts, gears and other elements "run" for a long time), however, problems may arise with the clutch assembly, sensors, actuators, electronic control unit, wiring and a number of other mechanisms, parts and assemblies ...

At the same time, in some cases, it may be enough to reflash the ECU and replace the clutch, while in others it is necessary to change expensive and officially non-repairable units.

Finally, we note that another disadvantage of DSG, especially DSG7 is their low liquidity at secondary market... This means that such a car, especially a premium model with low mileage, can be bought at a high price, but it will not be possible to sell it profitably later.

To put it simply, most motorists today are well aware of the problems of this box and simply do not consider cars with the specified type of gearbox. Another option could be to try to significantly reduce the cost of a used DSG car during bargaining. The reason is quite obvious, since the potential buyer separately takes into account the cost possible repair preselective robot, and such a repair may be required very soon.

How to use DSG box correctly

To begin with, the DSG delivers excellent acceleration and inherent fuel efficiency as well as comfort. As a result, the preselective robot has become one of the most promising types of gearboxes.

At the same time, even taking into account the similarity with the automatic transmission in terms of operation, as well as with the manual transmission in design, the operation of a car with DSG is somewhat different from an automatic transmission, mechanics and simple single-disk robots (AMT gearbox).

Moreover, some nuances arise even depending on what type of DSG is installed on a particular car model. For example, the DSG-6 box is “wet” (works in an oil bath), while the DSG-7 is “dry”.

At the same time, the clutch discs, both in the first and in the second case, wear out, and in the case of the DSG-7, this happens faster. This means that an aggressive driving style, sudden acceleration from a standstill, slipping, etc. for DSG-6 are still permissible, but this cannot be said about DSG-7.

The fact is that a clutch in an oil bath is more protected from wear and overheating than its "dry" counterpart. Also DSG-6 was originally designed for higher torque (about 350 Nm), while the 7-stage version "digests" no more than 250 Nm.

In practice, this means that tough exploitation will quickly disable the DSG-7. It is worth mentioning the cases when such a checkpoint did not take care of more than 50-70 thousand km. from the moment of purchase and required expensive repairs.

It is important to understand how to use DSG in a traffic jam and operate a car with this gearbox within the city. First of all, in order to save fuel, DSG in automatic mode usually quickly shifts from first to second gear. Moreover, if the driver presses the brake further or does not accelerate, the transition to the first speed occurs again.

It turns out that with such a "jerky" driving there is an accelerated wear of the gearbox and clutch, the clutch overheats, etc. To avoid this, it is optimal to switch to manual control using the semi-automatic transmission mode. To put it simply, the driver independently engages the first gear and does not switch to the second, if such a situation arises on the road.

Even in the list of rules that can increase the DSG resource, one should highlight the need to actively press the brake pedal when switching modes. In the event that the brake is not fully depressed, the DSG does not fully open the clutch discs, thereby increasing wear.

Also, the rule of switching to "neutral" at stops, which is relevant for "single-disk" robots, affects DSG to a lesser extent. In other words, switch to N mode at traffic lights and when idle for up to 60 seconds. unnecessary as frequent switching only increases wear. Moreover, when the brake is fully applied, the box itself opens the clutch.

You need to know that the DSG box (especially the 7-speed) is "afraid" of slipping even more than the automatic transmission. This means skidding in mud, on ice, when starting from a standstill in manual mode, etc. forbidden.

Also, when putting into the “parking” mode, it is necessary to use the parking brake in order to extend the service life of the limiter (locking mechanism), which prevents the car from rolling back. Switching between modes should be smooth, with a slight delay of about 1 second. During this time, the electronics will have time to "adjust".

It should be added that a car with DSG should not be overloaded by towing a trailer or other transport, as well as by transporting various goods in the car itself. In practice, an initially heavy car with DSG-7 (e.g. Skoda Superb) with full salon passengers and additional cargo can weigh about two tons. Given that the box is not designed for heavy loads, such a robot can suddenly fail.

As for the DSG-6, this gearbox is more durable and is paired with powerful engines. However, this does not mean that a car with such a transmission can be constantly used as a tug.

First of all, the DSG box needs maintenance, and more often than the manual transmission. For example, in DSG-6, the clutch works in oil, and the volume of the lubricant itself is also quite large.

For this reason, the oil change in the DSG must be done every 60 thousand km. mileage. At the same time, the transmission filter is also changing. At the same time, without proper experience and equipment, it is better to refuse self replacement in a garage.

We also add that if a car with a DSG is stuck in mud or snow, you need to refrain from intensive attempts to drive "into the swing". Better to put the box in N mode and use outside help, that is, pull out or push out the vehicle.

If there is a need for DSG, you need to adhere to the rules and recommendations, tow the car at the permitted speed and only for short distances. Information is usually contained in the manual.

What is the bottom line

As you can see, the operation of the DSG is quite reminiscent of the use of a classic automatic hydromechanical automatic transmission. However, there are some differences. For example, DSG allows you to switch from D to R mode without a slight delay in N. However, when it comes to slipping, the robotic transmission is most sensitive to them.

It should also be borne in mind that a robot with two clutches is a rather complex unit in terms of design. At the same time, in comparison with other types of transmission, DSG repair is often not only costly, but also problematic. The reason is that not every car service is capable of qualitatively repairing a DSG.

As a result, we note that even taking into account all the difficulties and potential problems, the DSG box is still the most preferred option when choosing a new car.

Also, the VAG manufacturer himself is constantly improving the design, making changes to the gearbox operation algorithms, improving the firmware of the electronic unit, etc. As a result, you can count on improved reliability and a sufficiently long transmission life.

1. What is DSG box

The driver selects the gears, and the electronics itself controls the clutch and gives the command to change gears. A distinctive feature of such nodes - double clutch and five shafts.

This solution made it possible to achieve the same acceleration and set times maximum speed as in the usual manual transmission... It would be correct to say that DSG is the next step in development. mechanical box gear. Such nodes are also often called "robots".

2. The device and technical subtleties of DSG boxes

DSG boxes are divided into two types - DSG-6 and DSG-7, the first is a six-speed version, the second is a seven-speed one.

DSG-6 has a large torque and operates on a “wet” principle. The mechanical parts are immersed in an oil bath, while the oil is circulated, thereby cooling the clutch assemblies and discs.

Such gearboxes are installed on vehicles with increased power:

Volkswagen Golf, Volkswagen Eos $
Skoda Octavia;
Audi TT, AUDI Q3.

DSG 7 is a dry box. Differences from DSG 6 - in reduced torque and dry clutch, transmission oil only used to lubricate the clutch discs. They are installed on low-power cars or on those in which the torque does not matter much. Due to the lack of normal cooling, they are disliked by motorists.

Examples of cars with seven-speed "robots":

Volkswagen Passat, Volkswagen Transporter;
Skoda Fabia, some Octavia;
Audi A3.

The principle of operation of robotic boxes ("robots") is as follows:

When the first gear is turned on, its gear is blocked, the clutch is closed and the moment is transmitted to the gearbox, at the same time the gears of the second gear are blocked. It turns out that two gears are working simultaneously, but the second clutch is open and ready to be engaged. By command on-board computer the discs of one clutch open and the other is turned on. Next, the gears of the third gear are blocked. As a result, the box is constantly ready to change the next gear. When slowing down, the cycle repeats, only in the opposite direction.

The common unit of such boxes is mechatronics, a unit that includes sensors, hydraulics, and electronic components. He monitors the readings of oil pressure, the position of the gears, speed and other parameters and, based on this, decides whether to shift to an up or down gear.

3. Advantages and disadvantages of "robots"

The robotic gearbox has many pros and cons.

The pluses include:

almost instant gear change;
Manufacturers declare fuel economy (controversial, perhaps in comparison with a conventional "automatic");
There is no engine power take-off, as with manual transmission control;
Manual control.

There are also many disadvantages:

The repair cost is high;
Unreliable mechanical part even in new models;
Expensive and complicated oil change procedure in DSG-6 boxes;
Poorly tolerates aggressive driving style.
cars with such a box are more expensive than conventional hydromechanical "automatic" and "mechanics".

For example, we will give a budgetary foreign car Skoda Octavia with an engine capacity of 1.4 liters.

The price for a complete set with mechanics is 1,034 thousand rubles, for a box with DSG they already want 1,074 thousand rubles, however, the manufacturer claims a fuel economy of 0.1 liters for every hundred kilometers. V dealership"Robot" will cost 40-60 thousand more expensive than conventional mechanics, 10-20 thousand more expensive than "automatic".

4. Opinions and reviews

Feedback from the owners of such cars is extremely contradictory. On the one hand, the barricades are satisfied with the choice of motorists, on the other hand, they are disappointed and trying to dissuade them from such an ambiguous acquisition. The State Duma even recorded an attempt to completely ban DSG 7 boxes in Russia. The argument was the concern for citizens, the deputies expressed the opinion that such a box is not safe for drivers. Fortunately, it didn’t even come to an initial hearing.

DSG proponents cite arguments such as “correcting mistakes” by DSG manufacturers (dubious merit), fast gear changes that do not depend on driving skill, low fuel economy, stable operation at low temperatures, positive dynamics. Ill-wishers are countered by the fact that they have incorrectly read the instructions for the car. Indeed, manufacturers recommend, in contrast to hydromechanics, to include neutral in traffic jams or at traffic lights. However, these are just tips.

There are much more opponents and more weighty arguments. Unreliability of software, difficult maintainability, often it is impossible to repair at all, the entire unit changes, and this affects the cost. "Garage" repairs are excluded, if even a conventional automatic transmission can be repaired in a car workshop with competent employees and a set of tools, then no one will take on DSG except for official dealers. Women complain about rolling back in traffic jams, men complain about the impossibility of a quick start from a traffic light (a tribute to reliability, when the first gear is connected, the box "thinks").

At the second speed, vibrations are felt, extraneous noises are heard in the box. A common phenomenon is a breakdown due to firmware, for example, "brains" stop recognizing even transmissions. It is believed that such systems are poorly compatible with gasoline, behave a little better with diesel fuel... In the heat on "dry" boxes clutch discs overheat, they cannot be repaired, only for replacement. It is not for nothing that the people say this: DSG - Two Clutches a Year.

There are far more bad reviews than positive ones. The negative nature of the responses is clearly visible. On the other hand, if everything were really so bad with them, such boxes would not have received such distribution, and judging by the models on which they are installed, there are still a lot of them. Perhaps auto concerns do not admit their mistakes, again, re-equipment of conveyors is a costly business, but making people believe in quality and reliability is the work of marketers and PR services.

5. Conclusions

The decision on the choice of a robotic gearbox is made exclusively by future owner... If you are not a fan of aggressive driving, you are ready to spend authorized dealer, you do not like the "lethargy" of the machines, but you also have no desire to lose comfort due to the clutch pedal - DSG is fine. Again, in pursuit of a customer, such boxes usually come with an increased warranty. For example, Volkswagen claims 150 thousand kilometers without repair. Those who like to leave abruptly from a traffic light are better off looking in the direction of the "mechanics". If small jolts and fuel consumption are not critical, buy a car with a conventional automatic transmission.

In Russian conditions, DSG does not take root very well. Perhaps, soon the engineers of corporations will find solutions to many problems, as has happened more than once, but so far "robots" are the most common lottery. Play it or not - the choice is yours. But if the question arose only about the DSG, then the choice of a six-speed model is preferable in terms of reliability and dynamics.

As you know, today automakers offer consumers, taking into account the ever-growing demand for this type of gearbox. In this case, the machine can be represented not only by the "classical" hydromechanical automatic transmission, but also a robot, a variator, as well as with two clutches.

Also, the main modes and the execution itself in the cabin in relation to different types The automatic transmission is often practically the same. This is for ease of interaction. In other words, when buying a car, it can be difficult to determine which machine is installed in a particular case, since the automatic transmission lever (), panel and available modes may be the same.

Taking into account the fact that different types of machines have both pros and cons, and also, in some cases, it is important to understand exactly which box is on the car. Next, we'll talk about how to determine if an automatic or DSG, as well as what to look for.

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DSG box or automatic machine: how to determine the type of gearbox

Let's start with the fact that it has established itself as a reliable, hardy and completely maintainable unit. At the same time, many potential owners choose this type of checkpoint even taking into account increased consumption fuel and some reduction in acceleration dynamics.

As for the preselective robots, combining the positive properties and the classic automaton.

On the one hand, the production of such a box is cheaper, which reduces the final cost of the car. The driver also gets almost imperceptible gear changes, high transmission efficiency, fuel efficiency and excellent acceleration dynamics.

However, on the other hand, the DSG resource (especially DSG-7) turned out to be noticeably lower (2-3 times) than that of torque converters. Also, the disadvantage is the high cost and complexity of repairing DSG, the need for nodal replacement of individual expensive elements, difficulty with setting, etc.

It is for this reason (as a rule, in the secondary market) that cars with DSG are sold worse than with automatic transmissions and even a variator. Buyers themselves often either refuse to purchase, or seek to reduce the price as much as possible, citing the possible need for serious repair of such a box already at runs of 100-150 thousand km.

Naturally, the seller of the car is not interested in significantly reducing the cost. If you remember that it is difficult to visually distinguish a DSG from an automatic machine, inexperienced buyers are often deceived, claiming that the car has a conventional automatic transmission, DSG, etc. Complexity is also added by the fact that some models can be equipped with both DSG and conventional automatic transmission.

Even in pursuit of profit or in order to quickly sell a car, in some cases sellers go even further, changing the automatic transmission selector with the inscription DSG to a simple handle, remove the DSG "nameplate" from the lever, completely pull the handle with leather, etc.

As a result, especially if there is a lever from a classic automatic machine, new owners often do not know what kind of transmission is actually installed on their car. So, in order to clearly understand which gearbox the car comes with, you need to be able to distinguish DSG from automatic transmission.

First of all, among the main distinguishing features of DSG are:

As you can see, given such a large number of different types automatic boxes, it is important to take into account their features and differences. In practice, you need to be able to distinguish.

The fact is that although all these types of transmissions are automatic, they differ from each other both in terms of design, and in terms of reliability and quality of work. For example, the CVT is the most comfortable gearbox, but not suitable for aggressive driving.

Automatic transmission can consume more fuel, while being more reliable. the cheapest, while the box is thoughtful, there may be jerks and failures at the time of gear shifting. As for the DSG, although such a gearbox works no worse than a classic automatic machine, the main disadvantage is the high price and low resource.

Finally, we note that, taking into account the above information, it is necessary to determine exactly which box is on the car, which may, as a result, become a reason for refusing to purchase or a reasonable bargaining with the seller.

What is DSG Box?

DSG is a second generation robot transmission that shifts gears using two clutches and electronically, with the assistance of the driver. Today it is considered best gearbox and the most reliable. It changes gears without breaking the power and has the best dynamic qualities. DSG also saves fuel, since the internal combustion engine does not idle.

DSG comes in six or seven steps. The first is installed on more powerful cars, since it has more torque. The seven-stage robot is installed on less powerful cars, as well as on some trucks and buses.

Short story

The DSG was first developed by Borg Warner. They wanted to create an ideal gearbox that would combine all the qualities of a manual transmission, an automatic transmission and a variator, and at the same time had no drawbacks. The shortcomings of the mechanics are known to everyone, the machine has a power consumption, and the variator has a narrow range of work. The robot had to absorb all these shortcomings, and plus reduce the cost of maintenance and repair.

But things didn't go as they wanted. It turned out that the six-speed gearbox is not suitable for low power cars. Then a seven-speed gearbox was additionally developed, which was suitable for such cars. But the excuses were not confirmed, because it was dry.

A year of work, testing, refinement and a new DSG has been implemented on some Volkswagen vehicles. Of course, there were some incidents, and the first batch was defective. But the plant quickly corrected everything and now the robot is widely used in many cars.

Principle of operation

The genius of the DSG box is that it combines two boxes in one body. It is equipped with two shafts, one with even gears and the other with odd gears. Two clutches, for each shaft, allow the most efficient gear shifting without loss of power and short braking, as in an automatic machine.

The six-speed DSG clutch is of the "wet" type (constantly in oil). This is done so that the discs are cooled and lubrication is constantly present. This function has significantly increased the resource of the checkpoint and it is about 300 thousand km. With careful use, it can stretch up to 450,000 km.

DSG-7, or seven-speed robot box, is equipped with a dry clutch. This is done to reduce the cost of maintenance and service, but at the same time increased wear and decreased resource.

What is the difference between a robot and an automatic transmission?

When buying a car, any car enthusiast thinks about which box is better to take? Repeatedly this confuses a person. So what is the difference between a robot and an automaton?

The first difference is constructive. The robot is made so that the car does not lose power, and gear changes do not slow down the dynamics. Second - technical difference: this is what a robot is mechanically structured and requires
driver's participation in gear shifting.

Other differences between the machine and the robot:

a robot is simpler than an automatic machine, since by its nature a robotic box is a mechanic;
the robot has electronics that controls the switching;
saving fuel by the robot;
the ability to change the settings of the robot for different kind and driving style;
manufacturability of the design for modernity;
high reliability and quality of the robot.

Pros and cons of DSG

The advantages are:

fuel economy (only in comparison with the automatic machine, there is more savings on the variator);
instant gear change;
no power loss;
high resource;
manual control.

Cons of DSG:

high cost of repair;
expensive oil change cost (for DSG-6);
does not tolerate aggressive driving style;
the cost of the car is more expensive.

Manufacturers' suggestions in robotic boxes

The manufacturer Volkswagen promises the completion of the robotic boxes, since they are not yet complete. The main problem that automakers pose for themselves is the reduction in the cost of maintenance and repair. Leaving
advantages, it is necessary to make repairs and maintenance cheaper, since not every ordinary consumer can afford to service a car with such a cost of spare parts and materials.

According to many experts, these boxes are the future, although 40 years ago they were considered not promising and practically dead options. Now they are recruiting supporters and those who would like to have a car with a box.
DSG, but can't afford it. But the manufacturers promise to do everything to make the most available to the average consumer.

Output
Having examined the DSG robotic gearbox, one can come to the conclusion that today it is the most perfect box, which combines all the advantages of mechanics and an automatic machine, while not expensive to maintain 😉, like a variator. It has enough advantages that modern drivers need.