DSG Transmission

[Wazza 162]

Out of interest, what benefit do people think they are achieving by engaging neutral when stationary? The clutch throw out bearing isn’t going to wear out that fast.

Its not so much the thrust bearing as much as the the clutch plates slipping, similar to a manual transmission sitting for a long period with foot on the clutch.

[doc_777]

Its not so much the thrust bearing as much as the the clutch plates slipping, similar to a manual transmission sitting for a long period with foot on the clutch.

Well, I reckon it’s not an issue because in no way should there be any grab between the plates when the clutch is disengaged, but to each their own.

[Spinifex]

Well, I reckon it’s not an issue because in no way should there be any grab between the plates when the clutch is disengaged, but to each their own.

Read my reply above !!!

There is commonly-documented evidence throughout the internet, which indicates the plates do NOT disengage fully..... this is why some of us go into Neutral.

[doc_777]

Read my reply above !!!

There is commonly-documented evidence throughout the internet, which indicates the plates do NOT disengage fully..... this is why some of us go into Neutral.

you read it on the internet so it must be true.

its obvious that you don’t understand the conditional logic around idle speed variation for one thing.

anyway, it’s your car.

[Spinifex]

You clearly didn't read my original reply on here. And I knew someone would try to negate the opinions of many other people who describe the exact same behaviour and concerns, as being "the internet is never wrong"

SO many people with identical issues/concerns documented is not a case of me blinding accepting everything I read on the internet.

It's obvious that you believe conditional logic can't be faulted at all. That's why computers NEVER fail and cause catastrophic accidents?

Kindly explain to us, how "conditional logic around idle speed variation" works, and how it makes us incorrectly assume the clutches are still semi-engaged when in-fact, they are not?

But make sure it's believable..... coz, the internet and all....

[doc_777]

Abient temp
coolant temp
Throttle position
gear selector position
transmission mode
transmission temperature
vehicle speed
brake pressure
aircon compressor clutch status

those are just some of the conditions which the ecu uses to determine the idle speed

example - aircon clutch status changes - the idle speed changes because the ecu caters to the change of load. Likewise selecting neutral (you don’t actually select neutral, you change the position of a switch, and the transmission controller does its thing) - the trans controller tells the ecu about the change of transmission status and the ecu then determines the required idle speed based on every other condition that has input to determining idle speed.

computers don’t fail and cause catastrophic accidents as you claim. It’s either a software fault (which was coded by a human), or a hardware fault (with inadequate failover redundancy).

[doc_777]

Let’s not forget one more salient point - an idle speed of ~800 is preferable to ~1000 from a clutch wear perspective on takeoff. An Idle speed of ~1000 is preferable to an idle speed of ~800 from an engine efficiency perspective. So it’s no surprise to me that the idle speed increases when the tcu tells the ecu that a neutral gear position has been requested.

[Ozsko]

Read my reply above !!!

There is commonly-documented evidence throughout the internet, which indicates the plates do NOT disengage fully..... this is why some of us go into Neutral.

If this was the case any DSG car caught in a heavy traffic jam for any length of time would have the clutch on fire if it had any slipping as you describe at all. It can't do any harm to shift into neutral but I think what someone had done is noted that if a DSG car is not on auto hold and the foot brake is released it creeps and has extrapolated that because the engine speed did not rise the clutches must be partially engaged at all times. Slipping clutches as you describe simply are not tolerable.

[tigger73]

This is part of the reason the 7speed DQ200 dry clutches stuff up as they basically cook themselves in slow moving city traffic.


Sent from my iPhone using Tapatalk

[Spinifex]

........those are just some of the conditions which the ecu uses to determine the idle speed......

While they are all very good examples, they don't count for the experiences (backed up by documented evidence elsewhere) that I described in my original post. Aircon kicking in is NOT the reason why many people notice the change in engine-revs and "assume" the gearbox clutches are disengaging. Anyone who posts about this issue obviously has at-least a tiny idea of how car mechanisms work, and we wouldn't be so blindsided by an AC clutch engaging/disengaging at an identical moment we manually shift from D to N, to assume it's the gearbox and not the AC.

... computers don’t fail and cause catastrophic accidents as you claim. It’s either a software fault (which was coded by a human), or a hardware fault (with inadequate failover redundancy).

Exactly my point... regardless of it being either software or hardware-related, computer/electronic systems DO still fail, which can cause catastrophic accidents.
Your comment does nothing to invalidate my statement, and merely reinforces it, so thankyou for that one

......but I think what someone had done is noted that if a DSG car is not on auto hold and the foot brake is released it creeps and has extrapolated that because the engine speed did not rise the clutches must be partially engaged at all times.....

While that may be true of some of the reports that have been documented, it's not the convincing argument in all of them (or my particular case)

When stopped on a flat surface with no incline, foot mashed on the brake, shifting from D to N, there can occasionally be the following results:
A: revs change
B: audible change in engine tone
C: this is the kicker.... the car MOVES ever so slightly... you can physically feel the car releasing the "tension" or pre-loading, for want of a better term. It is an IDENTICAL feeling to shifting D to N in a traditional slush-box automatic.
It is akin (in reverse) to when a motorbike is sitting in Neutral, and clicks down into 1st gear.... even when holding the clutch in tightly, the gearbox kicks in with SOME engagement of the clutches... you can physically see, hear and feel the chain moving/tightening on the wheel.