The DSG gearbox was the first dual-clutch transmission to hit the market. We discover everything about her.The well-known and widespread dual-clutch transmission in the industry has hardly been around for a long time, and we owe it to the Germans. Each manufacturer will call it as they wish, with acronyms and names that match the nomenclatures of each one, but the most important is the Volkswagen Group’s DSG gearbox.
While it is often advertised as an automatic auto clicker download gearbox, this is technically a complete mistake. The DSG gearbox, and with it the rest of the double clutch gearboxes, are robotic or automated manual gearboxes. DSG Gearbox is used also in some of the VW Vans. In practice, its operation has led us to the error of considering it an automatic gearbox.
Pioneers in this technology
The first prototypes of dual-clutch transmissions date back to the 1960s, when Porsche began testing this type of gearbox on various units of the Porsche 911 RS 2.7. The next time this type of change was put to the test was already in competition, in the 1980s, with the Porsche 962 and the 24 Hours of Le Mans as the protagonists.
DSG gearbox components
The DSG gearbox starts from a manual gearbox –of whatever ratios are required– synchronized with helical gears. Unlike a manual gearbox, the clutches on the DSG are bathed in oil. It has two axes, the primary and the secondary, inserted one inside the other. These are the ones in charge of preselecting the gears.
The primary shaft engages the odd and reverse gears, while the secondary shaft engages the even gears. To these is added a third shaft in charge of moving the oil pump, which is necessary for the drive and lubrication of the transmission.
Both the idle spinning sprockets and locking when the synchro spool is shifted act unchanged from the operation of a manual gearbox.
Contrary to what you usually think, the maintenance of an automatic change – periodic oil change – or a DSG is not infinite. On the contrary, in cases such as double-clutch transmissions, the oil is as or more important than in a manual because, in addition to the gears, the clutches are also bathed in oil.
DSG gearbox operation
The complete set can be considered as two gearboxes in one, since its components in application resemble it. Its main characteristic is that of having two permanently meshed ratios, one for each helical train, while only one clutch is connected.
The changes between relations –from odd to even– are carried out as follows. Both the primary shaft and clutch 1 (E1) are engaged in their corresponding gear, in which the vehicle is running, while the secondary shaft has the next gear engaged, but without engaging clutch 2 (E2).
When the electronics detect that it is the optimum moment for the change, it activates the oil shut-off valve so that the E2 engages and the E1 disconnects. After the change between clutches, the input shaft has already prepared the next odd gear even without engaging the clutch.
It has two operating modes: D and S. The first is the classic automatic, in charge of everything and prioritizing ride comfort and fuel consumption. For its part, S mode will require the driver to change gear, either by paddles behind the wheel or sequentially from the selector lever itself.