DSG box. The life of the Volkswagen dual-clutch transmission is 20 years

In France in 2021, more than one in two new passenger cars will be equipped with an automatic gearbox. A trend that we owe in large part to Volkswagen Group, in the origin of the democratization of dual-clutch technology with its DSG box. Celebrating his twentiesAnd the birthday, argus Looking back at its operation and history but also reliability issues…

The gear lever design has evolved over the years.

More smoothness, less consumption

Even if there were already several types of automatic transmission before its birth (transformer, continuously variable, etc.), the DSG was a real revolution. I actually proposed cruising down the trails at speeds unprecedented at the time, without lacking the smoothness of simple clutch automatic transmissions. Qualities inherent in the way it works. The entire mechanism consists of two gearboxes, each of which is connected to its own clutch and to the drive shaft, which is also divided into two parts. Volkswagen specifies that “one shaft is for single gears and the other is for single gears and vice versa. Thus, two gears can be engaged at the same time: one engaged and one disengaged.”

dsg gearbox diagram
The DSG consists of two independent semi-boxes, each of which functions almost like a mechanical box.

This simultaneous operation of the clutches makes it possible to avoid torque interruptions. The gears can thus be changed quickly and smoothly, all without consuming much more than a car equipped with a manual gearbox. This automatic transmission also gives you the choice: change gears sequentially, via the lever or paddles on the steering wheel, or let the electronics do their work. But as we will see later, the dual-clutch gearbox is expensive, heavy, and not the most powerful automatic system.

From track to road

Although the dual-clutch gearbox was invented in 1939 by a Frenchman, it was in the 1980s that the technology really came into the car. It was first used for endurance racing by Porsche with its 956 and 962 models. A victory at Monza in 1986 would follow, but most of the many successes of these two 24 Hours of Le Mans monuments will remain with the classic mechanical boxes. Audi will also be testing this technology on a racing beast: the Quattro Sport S1.

Porsche 962 front track
The Porsche 962, which participated in endurance racing in the 1980s, had already tested a dual-clutch gearbox without much success.

Twenty years passed until the DSG (for Direct Shift Gearbox) was announced in 2002. It was designed by equipment manufacturer BorgWarner and then used by Volkswagen. It was emulated by other manufacturers, for example, Hyundai, Kia or Renault, which use the Getrag transmission or the previous FCA group (Alfa Romeo, Fiat, Jeep, etc.) due to its energy efficiency.

vw golf r32 front
The Golf 4 R32 had better performance once it was fitted with the DSG gearbox.

Launched in 2003, the Golf R32 was the first production model to benefit from a dual-clutch gearbox. The German then proceeded with a 241-horsepower V6 under the hood, linked to all-wheel drive. offered as an option, This automated gearbox was to revolutionize driving but above all to prove that you can enjoy a sports car with only two pedals.

According to Volkswagen, the compact DSG ” It can reach 100 km/h in 6.4 seconds – compared to 6.6 seconds for the six-speed manual version – and consumes less fuel..

me’Audi TT, equipped with the same mechanics, will also introduce the DSG (later renamed S tronic) shortly thereafter. In the face of this success, the Touran, Golf, Polo and other Passats will use the automatic gearbox with 6 and then 7 speeds, in both petrol and diesel versions. Today, the entire Volkswagen Thermal Range (apart from the compact size! for cost reasons) delivers just that. Plugged hybrid versions add a third clutch to disengage the combustion engine when not in use.

Audi TT box DSG
The Audi TT, released in 1999, will take over the DSG box right after the Golf R32 from 2003, on its version equipped with the same V6.
Volkswagen Tiguan 2021 front road
Over the years, this type of transfer has been extended to most of the thermal range.

reliability issues

Aside from its fame, the DSG Box has had several setbacks since its launch in 2003. The six-speed version (DQ 250), for example, had problems with a warning light or “squeak” on startup. But if it improves over time, it won’t be for the DSG7 (DQ 200). Arrived in 2008 on smaller models, their reliability has been tested. The malfunction of the dry clutch system, without lubrication, which prematurely damaged the parts listed according to the usage profiles (city, mountain…). Vibrations and other malfunctions persisted.

Skoda dsg detail box
The DSG box gradually spread to other brands of the group: Audi, Skoda, Seat, Lamborghini or even Bugatti.

In addition, Volkswagen’s after-sales service has often been criticized for its lack of generosity. For several years the manufacturer considered that DSG clutches were wearing partsand they didn’t make any commercial effort until 2014. In addition, if Volkswagen’s workshops hadn’t touched a defective DSG, they were trained to open and repair this type of transmission without having to replace it entirely.

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