Are not equipped with the Audi and Volkswagen cars his gearbox DSG, perhaps, and it would have remained just curious to those drivers, which in addition to the car itself is also interesting device of its components and assemblies.
But the popularity of cars of both brands raises questions of another kind: DSG securely and what it can upset bought an Audi or Volkswagen with her? And this is not an easy case. To understand that it may break with associated fault DSG, will have to make an excursion into its design.
7 photos and text
Why is it so styled
DSG name is an abbreviation of the German or English DirektSchaltGetriebe Direct Shift Gearbox. There is a version of the same box, which Audi calls S tronic, but principally from the DSG, it is no different. Also of VW and Audi DSG mounted on Skoda and Seat.
Spot varnish on the electronic board of the control unit indicates the place where broken off transactions
Pure DSG - Manual, but the gear shift is not in it as in conventional PCR and terminology developers without breaking the flow of power. In conventional PCR, the gap happens exactly when the next transfer: driver presses the clutch and power from the engine to the drive wheels is no longer transmitted - the engine is idling, the fuel is burned in vain, which affects the dynamics and efficiency. Here are the origins and characteristics of DSG, distinguishing it from other INC.
Almost always, the main feature is called DSG have two, not one, as usual clutch. But still wiser. In fact, two boxes, too, but they are cleverly integrated into one body, do not immediately understand where one ends and another begins.
On top of the box housing has a water-oil heat exchanger, "tied" to the engine cooling system
If the two boxes, and the primary shaft to which engine power is transmitted, also two, each with a personal grip. One of the primary gear shaft are odd-numbered gears and reverse, the other - the even. When the car drove off the 1st gear at the same time it is already included in the DSG and 2nd gear. In a conventional PCR, this situation will inevitably lead to breakage. The DSG does not happen, because it is off the clutch shaft gear even. In essence, the 2nd gear is waiting in the wings, and when he comes, the odd gear clutch is opened, but the same power flow immediately picked up by ganging disc clutch gear and even lossless passed down the kinematic chain to the drive wheels of the vehicle. On another repeated the same trick.
Who around the head
DSG Another feature is that it is automated. Or robot that will be more accurate, since the PCR with automatic control to position them on the hydromechanical automatic transmission and CVT, called "robots". The gears are included with the help of ordinary synchronizer sleeve, but the fork moving cylinders, hydraulics also turns on and off the clutch, and all this economy manages Mechatronik, which are concentrated in the module electronic and electro-hydraulic control system components.
Input shafts. Top - even gears, bottom - odd and reverse. Val even gears hollow shaft extends therethrough odd gears when DSG collected. This trick allowed to place in the same housing two 3-speed manual
Even when the driver, to amuse vanity driver selects the manual shift, he actually shift lever is not "mixing" the gears in the box, and with built-in selector Hall sensor only sends CAN-bus electrical signals to the control unit by pointing Mechatronik that he should take.
Hardly location Mechatronik inside DSG can be called essential distinguishing feature of this box, but the focus should be on it, because we came very close to one of the pitfalls. Perhaps the best place of the layout considerations for the control unit and will not find, however, in terms of reliability is nothing good about it.
The Mechatronik module focused electronic and electro-hydraulic control system components
While in winter cold car is parked, the unit with the box is cooled to ambient temperature. Then, when the vehicle traveled, Mechatronik heated to a temperature, which oil becomes in a box, and it may be heated strongly. Not for nothing is on the body of the box has a water-oil heat exchanger, "tied" to the engine cooling system. To the effects of temperature changes added vibration. The manufacturer guarantees the performance of the unit at temperatures from -40 ° to + 150 ° C and vibratory loads up to 33 g, but the event of failure of the control modules DSG known. Curious repair specialists boxes to get to the reason why these units were opened and found to break off their electronic wiring boards. Why would?
The heat exchanger is also potentially unpleasant place. Information on depressurization and mixing the oil with anti-freeze specifically DSG we do not have, but such cases are known in other KP having a similar cooling system.
Wet and dry
It is known that MCP can operate for a long time, without the need for repair procedures. However, all also know that during this period the clutch may require replacement several times.
On the 6-speed DSG, debuted in 2003, the multi-disc clutch "wet" - packages drives work in oil, which lubricates them and and cools
On the 6-speed DSG (VW factory designation 02E), which debuted in 2003, the multi-disc clutch "wet" - packages of disks working in the oil that lubricates and them, and cool. The only bad oil, because the cycles of heating-cooling benefit not go. But the clutch enters the repair is so rare that even professionals involved in the repair manual, difficult to answer as it can withstand.
In 2006 there was a 7-speed DSG (VW 0AM) developed for models with engine torque less than 250 Nm (6DSG «digest» up to 325 Nm). He Clutch "dry", like the conventional clutch. The good news: If you need to serve 6DSG 6, 4 liters of oil, the 7DSG comes less than two. The bad news: you should not have illusions that the resource of the clutch twice, because they are two, not one, in a simple box. Clutch wear when not fully turned on or off, and at a slipping clutch disc accompanying the switching on and off, but these procedures in each of the two clutches run parallel. Moreover, in addition to the slave drives a weak point in the clutch 7DSG are also plastic push tube. These nuances are to ensure that repairs are "dry" clutch 7DSG gets far more often than "wet" in 6DSG.
Before the advent of dual-mass flywheel Some car owners even had no idea that this unit may require replacement
Completes the picture of a two-mass flywheel. Before the advent of such structures, some car owners even had no idea that this unit may require replacement. The DSG it needs to be replaced regularly.
Sum up prematurely. We have identified some, but not all the problems of DSG, identified in the operation, and not touched upon the issues of repair of these boxes, and its value.
author: Sergey Boyarsky