Question about DSG operation

n1das

TDIClub Enthusiast, Veteran Member
Joined
Jun 11, 2002
Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
Today at lunch a couple of co-workers and I were talking about how a DSG tranny works. A question we weren't able to answer is how does a DSG tranny make the transition from the car being stopped and in neutral to in gear and moving? Does it have a torque converter like a slushbox auto tranny and then locks up afterward? Do the DSG clutch(es) engage slowly/smoothly for a seamless launch?

I'm a diehard manual tranny driver and I'm trying to figure out how a DSG tranny handles the equivalent of what I have to do to put the car in gear and hook up to the engine and get the car moving without stalling the engine or abusing the clutch and doing it smoothly. Manual tranny driving is second nature to me and my preference with tranny choices but I'm curious about how a DSG tranny does this sort of "balancing act" at startup.
 

Plus 3 Golfer

Veteran Member
Joined
Oct 29, 2008
Location
ARIZONA
TDI
Und tschüss! 2009 Jetta 12/23/2012
No torque converter. It really operates like a manual transmission but instead of the driver making decisions on when to shift, a control module decides when to shift. Search as there is a link somewhere for a VW self study guide on the DSG.

The DSG has multi-plate clutches (that are operated by fluid pressure and controlled by the control module) and synchronizers like a manual transmission that match speeds for smooth engagement of gears when shifting. There also can be some slip of the clutches based on the pressure applied to the clutches. When the car is stopped, the clutches are open. If you are stopped and simply take your foot off the brake, you will fell a slight bump as first is engaged.

The DSG is like two manual transmissions in one allowing for a compact design. It has one input shaft and two independently controlled clutches that drive output shafts - one output shaft is for gears 2,4,6 and the other output shaft is for gears 1,3,5. The two output shafts drive the differential.
 

n1das

TDIClub Enthusiast, Veteran Member
Joined
Jun 11, 2002
Location
Nashua, NH, USA
TDI
2014 BMW 535xd ///M-Sport, 2012 BMW X5 Xdrive35d, former 3x TDI owner
Thanks guys. Big help.

I'm a manual tranny diehard and haven't seriously studied DSG operation much. I test drove a Tiguan gasser last year and the DSG operation was 100% seamless. :cool: I was checking out the Tiggy so see if it were something I would want if it were someday offered here with a TDI engine.(probably won't happen :( )

Thanks again.
 
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