DSG gearbox - slight shudder before stopping

[Nick_B]

Hi All,

As someone who is new to the DSG box - one observation and one query...

I notice the sometimes, when breaking very gently to a halt (with stop / start switched off), there is a tiny, almost imperceptible 'shudder' before the car comes to a complete halt. With my limited knowledge of the workings of DSG, this feels as if the clutches are waiting until the final moment to disengage thus bringing the engine almost to the point of stalling. Anyone else notice this....?

Also - whenever I have driven traditional 'torque-converter' automatics I tend to shift the transmission into N when stopping for anything more than a few seconds on the assumption that this removes stress from the drive train. From what I have read this is not necessary with DSG as the box essentially disengages when stationary however I cannot get definitive confirmation of this so interested to hear views.

Nick

 

[jds_sg]

Hi,
I haven't really noticed the near stall you describe with start/stop switched off. However, if the start/stop is on then it is activated by brake pressure, so if you squeeze a bit harder it can invoke the start/stop, releasing slightly can just catch it before the engine stops. This can sometimes cause a similar behaviour to what you describe, and can be quite annoying. Just another reason to shift into S mode as it deactivates start/stop.

No need to shift into N when stopping in traffic, the gearbox will do it for you, provided you have firm enough brake pressure.
Take a look at this video for some more general dual clutch gearbox advice, the first point deals with the neutral question.

 

[Nick_B]

Thanks - that is really useful and does answer the 'N' question.

Regarding the shudder - it is virtually imperceptible - and I have found one reference to it

https://www.audiworld.com/forums/a4...n-disengages-clutch-when-coming-stop-2930701/

With an explanation....

I just did a 1300 miles road trip in an Allroad and I own an RS5, so both S-tronic transmissions. There is a tendency for the clutch to get released late if you come to a grandma stop. The TCU basically isn't sure if you are going to stop or if you just drive really slow. Eventually, the engine reaches almost stall speed and the clutch disengages to avoid stalling the engine. Be more assertive when coming to a stop and this shouldn't happen. I don't really experience this unless I'm stuck behind a grandma driver, so to say.

I only notice it occasionally so I guess just a quirk / feature of the transmission. I am absolutely not concerned about it.

 

[cuke2u]

Possibly just a dsg trait, but I've not noticed it myself. Perhaps it is because I am happy to use start stop with coasting...

 

[Paul Golding]

Interesting, as I find this happening too, but with little logic or predictability. In fact I've just got used to it and assumed it was actually just a random clunky downshift to 1st.