#7 DCT TRANSMISSION DRIVER#
#7 DCT TRANSMISSION MANUAL#
#7 DCT TRANSMISSION SERIES#

#7 DCT TRANSMISSION MANUAL#

In principle, the DCT behaves just like a standard manual transmission: It's got input and auxiliary shafts to house gears, synchronizers and a clutch. Hopefully it's becoming clear why the DCT is classified as an automated manual transmission. We'll look at the pros and cons of dual-clutch transmissions next. This allows the piston springs to relax, which eases pressure on the clutch pack and pressure plate. To disengage the clutch, fluid pressure inside the piston is reduced. Audi's dual-clutch transmission has both a small coil spring and a large diaphragm spring in its wet multi-plate clutches. In turn, the drum is connected to the gearset that will receive the transfer force. The friction discs have internal teeth that are sized and shaped to mesh with splines on the clutch drum.

#7 DCT TRANSMISSION SERIES#

When the clutch is engaged, hydraulic pressure inside the piston forces a set of coil springs part, which pushes a series of stacked clutch plates and friction discs against a fixed pressure plate. The fluid does its work inside the clutch piston, seen in the diagram above. Like torque converters, wet multi-plate clutches use hydraulic pressure to drive the gears. Many motorcycles have single multi-plate clutches. Several manufacturers are developing DCTs that use dry clutches, like those usually associated with manual transmissions, but all production vehicles equipped with DCTs today use the wet version. A 'wet' clutch is one that bathes the clutch components in lubricating fluid to reduce friction and limit the production of heat. Instead, DCTs currently on the market use wet multi-plate clutches. DCTs, however, don't require torque converters. Sequentially, it works like this:īecause a dual-clutch transmission is similar to an automatic, you might think that it requires a torque converter, which is how an automatic transfers engine torque from the engine to the transmission. Using this arrangement, gears can be changed without interrupting the power flow from the engine to the transmission. One clutch controls the odd gears (first, third, fifth and reverse), while the other controls the even gears (second, fourth and sixth).

In a DCT, however, the clutches operate independently. Sophisticated electronics and hydraulics control the clutches, just as they do in a standard automatic transmission. Instead, power delivery changes from on to off to on during gearshift, causing a phenomenon known as 'shift shock' or 'torque interrupt.' For an unskilled driver, this can result in passengers being thrown forward and back again as gears are changed.Ī dual-clutch gearbox, by contrast, uses two clutches, but has no clutch pedal. So, in a conventional manual transmission, there is not a continuous flow of power from the engine to the wheels.

#7 DCT TRANSMISSION DRIVER#

Once the new gear is engaged, the driver releases the clutch pedal, which re-connects the engine to the gearbox and transmits power to the wheels. Devices called synchronizers match the gears before they are engaged to prevent grinding. Then the driver uses the stick shift to select a new gear, a process that involves moving a toothed collar from one gear wheel to another gear wheel of a different size. This operates a single clutch, which disconnects the engine from the gearbox and interrupts power flow to the transmission. When a driver wants to change from one gear to another in a standard stick-shift car, he first presses down the clutch pedal. To understand what this means, it's helpful to review how a conventional manual gearbox works. Hands-On or Hands-OffĪ dual-clutch transmission offers the function of two manual gearboxes in one. This article will explore how a dual-clutch transmission works, how it compares to other types of transmissions and why some predict that it is the transmission of the future.

7 dct transmission