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.”
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.
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.
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..“
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.
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.