How do Dual Clutch Transmissions work? DSG, DCT, PDK, S-tronic. Auto transmission gearbox animation

A dual-clutch transmission (DCT) (sometimes referred to as a twin-clutch transmission) is a type of multi-speed vehicle transmission, that uses two separate clutches for odd and even gear sets. The design is often similar to two separate manual transmissions with their respective clutches contained within one housing, and working as one unit. In car and truck applications, the DCT functions as an automatic transmission, requiring no driver input to change gears.
The fundamental principle of a DCT is that one clutch drives a gear-set for the even-numbered gears, while the other clutch drives the odd-numbered gears. Since the DCT can pre-select an odd gear while the vehicle is being propelled in an even gear (or vice versa), DCTs can shift several times faster than is possible with a manual transmission. By timing the operation of one clutch to engage at the precise moment that the other is disengaging, a DCT can shift gears without interrupting the torque supply to the wheels.
A DCT uses clutch packs (as per a manual transmission), rather than the torque converter used by traditional (hydraulic) automatic transmissions. The DCT clutches are either "wet" or "dry" and are similar to the clutches used in most motorcycles. Wet-clutches are bathed in oil to provide cooling for the clutch surface, therefore wet-clutches are often used in applications with higher torque loads, such as the 1,250 N⋅m (922 lbf⋅ft) engine in the Bugatti Veyron.
Several arrangements for the two clutches are possible, and are outlined below:
Most automotive DCTs use two concentric clutch packs located on the same axis as the flywheel. Therefore, the outer clutch pack has a larger diameter than the inner clutch pack.
Many DCTs for tractors (such as the Fortschritt ZT 320) use a similar arrangement where the clutches are located on the same axis of the flywheel. The difference is that the clutches are at different positions on this axis (i.e. one in front of the other) and the same size as each other. This design is used by the Tremec TR-9070 DCT used by the 2020 Ford Mustang Shelby GT500.
Another design (as used by the Volkswagen DQ200 transmission) arranges two identical-size clutches located side-by-side. This design requires two side-by-side input shafts, which are driven from the crankshaft via gears.
#dct
#dsg
#dualclutch
#transmission
#auto
#automotive
#gearbox
#pdk
#stronic
#vw
#dq200
#dq250
#DL501
#p0701
#mechatronics
#P0562
#fault
#howdoesitwork
#how
OBDII CODE VAG CODE DESCRIPTION
#P0562 16946 System Voltage too low
#P0701 17085 Mechatronic Module defective
#P072B 21159 Gear R not selectable
#P072C 21153 Gear 1 not selectable
#P072D 21154 Gear 2 not selectable
#P072E 21155 Gear 3 not selectable
#P072F 21156 Gear 4 not selectable
#P073A 21157 Gear 5 not selectable
#P073B 21158 Gear 6 not selectable
#P073C 21159 Gear 7 not selectable
#P0746 17130 Pressure Control Solenoid 1 open / short to ground
#P0841 10784 Transmission Fluid Pressure Sensor/Switch 1
#P0850 17234 Park/Neutral Switch Input Circuit
#P0868 17252 Transmission Fluid Pressure Adaptation at Limit
#P1604 18012 Internal Control Module
#P1624 18032 MIL Request Signal Active (Check TCM for errors too!)
#P1701 18109 Transmission Control Unit locked
#P1707 18115 Interference in Mechatronic Module
#P174C 10742 Valve 1 in Transmission Part 2 malfunction
#P175D 10693 Clutch 1 Opens Unintentionally
#P175E 10694 Clutch 1 Closes Unintentionally
#P176A 10725 Gear Selector 1 Cannot be Regulated
#P176B 10726 Gear Selector 2 Cannot be Regulated
#P176C 10727 Gear Selector 3 Cannot be Regulated
#P176D 10728 Gear Selector 4 Cannot be Regulated
#P176E 10694 Clutch 2 Opens Unintentionally
#P176F 10696 Clutch 2 Closes Unintentionally
#P1775 10047 Hydraulic Pressure Sensor 1 (G193) P limit reached
#P177B 10806 Clutch 1 tolerance limit reached
#P177C 10778 Clutch 2 tolerance limit reached
#P179E 17597 Selector Lever Sensor malfunction
#P17BF 6079 Hydraulic Pump play protection
#P17D4 10902 Valve 3 in Transmission Part 1 malfunction
#P17D5 8960 Valve 3 in Transmission Part 2 malfunction
#P17D6 18443 Clutch 1 pressure too high
#P17D7 18444 Clutch 2 pressure too high
#P17D8 8040 Torque Restriction due to Clutch Temperature
#P17E0 17593 Sensor for Gear Actuator 1 malfunction
#P1814 18222 Pressure Control Valve 1 (N215) open / short to ground
#P1815 18222 Pressure Control Valve 2 (N215) short to +
#P1818 18227 Pressure Control Valve 1 (N216) open / short to ground
#P1819 18228 Pressure Control Valve 2 (N217) short to +
#P1895 10812 Functional Restriction due to Pressure Drop
#P1898 18306 Clutch 1 function restriction
#P1899 18307 Clutch 2 function restriction
#P189A 10817 Clutch 1 clearance too small
#P189B 10818 Clutch 2 clearance too small
#P189C 10878 Function Restriction due to Insufficient Pressure Build-Up
#P2711 19143 Unexpected / Implausible Mechanical Gear Disengagement

[@EfficientMan]

One of these things that take time to grasp, especially when there is a shaft in another shaft, the difficult thing to understand was what is happening with the pre selected gears' shaft, I guess it continues turning freely on the other shaft, and the gears somehow are attached to inner shaft without affecting the outer.

[@jbrivera6574]

Thanks for PDK transmission Dual Clutch

[@ccflan]

the fact that this type of transmission produce a lot of energy loss due to it's weight and a lot of engaging parts, but why people say that i have many cons ?

[@EfficientMan]

Everything has losses more or less, a car weighs 1 tonne to move people who weigh only 75kg, even 5 people would be 400kg, the rest is just moving the car... small proportion of usefull load. 20kg or even 50kg of more weight of an extra clutch is not a big deal. So, the only way not having losses is not having cars... or ships, or aeroplanes... This system has marginal more losses due to weight but is more easy to use. Besides, the fast and efficient shifting that this system does maybe makes up for these losses. Learn to live with the losses. Don't worry about it. Or if you want to worry stop using everything!

[@ccflan]

​@@EfficientManTo be honest, even a small amount of friction can make a significant difference over a long period. For example, a manual transmission car is lighter and has less friction, leading to better fuel economy in the long run. The European Union removed spare wheels from cars because they add extra weight. This added weight, multiplied by millions of cars, results in increased fuel consumption. Airplanes also worry about the weight of paint. They typically choose white because other colors can add weight, leading to additional costs of around 20,000 euros per year.

[@EfficientMan]

@@ccflanI don't know what EU did, but even if they did all these they didn't remove functional pieces of the aeroplane or car engines. DCT adds weight like an electric starter adds weight, we don't remove the starter to make the car lighter because it would be difficult to start... The air condition also adds weight and losses but we want it... Where are you going with this regulatory thing?

[@mogadimetsosanele2285]

Ehy its quite hard to understand