[JoshMachine]

Originally Posted by Sutripta

@JM- great post!
Does the DSG gearbox oil come in contact with ambient air?

Thanks Sutripta!
There is no direct contact with outside/ambient air as such, however given the location of the gearbox in the car underbody, it maybe susceptible to the outside temperature conditions (one of the main reasons investigated by VW to be the culprit for failure of the synthetic oil in the 7-speed box)

[Sutripta]

Originally Posted by JoshMachine

Thanks Sutripta!
There is no direct contact with outside/ambient air as such

So how does humidity enter the picture?

Regards
Sutripta

[Sankar]

Originally Posted by Sutripta

@JM- great post!
Does the DSG gearbox oil come in contact with ambient air?

I think it does have a breather. Guess it won't be hermetically sealed then?

Essentially we think alike!
The ZF 9 speed, like the DSG, is building up a nice unreliability reputation!

Regards
Sutripta

It is nice to know you have similar feelings for DSG
ZF9speed is a problem gearbox though a torque converter one. There have been recalls associated with this gearbox, I posted the same in Compass official review back then. Honda and other brands also had problems with the ZF9speed in their vehicles.
--

Edit: Please read "Damascus" as "Damocles" in my previous post. I blame too much Forged in Fire for the error

[jnpai]

@ JoshMachine.

Thanks for the brilliantly and painstakingly compiled post.

Though the technical and engineering aspects of DSG are a little bit advanced for me to fully understand, I really enjoyed going through the post. May be a second reading, which I intend to do will clear the missed points.

The links to ownership reviews are enormously helpful and to be read by all DGS owners and prospective buyers too.
As a Vento TSI owner, I'm glad I got to read your article.

Your article is the new Gita and Bible of DSG.

Moderators must consider giving this a 7 star rating.

[JoshMachine]

Originally Posted by Sankar

I think it does have a breather. Guess it won't be hermetically sealed then?^

Spot-on, Sankar. The DSG does have a breather cap (plastic seal) on top which allows some "breathing" for excess hot air to be released.
This also allows any leaking oil to be let out, if there is a malfunction inside the gearbox oil circuit.

Edit: Please read "Damascus" as "Damocles" in my previous post. I blame too much Forged in Fire for the error lol

Done

Originally Posted by jnpai

Thanks for the brilliantly and painstakingly compiled post.
Though the technical and engineering aspects of DSG are a little bit advanced for me to fully understand, I really enjoyed going through the post. May be a second reading, which I intend to do will clear the missed points.

Thanks jnpai !
Not to worry on the tech stuff, even I don't hold a degree to qualify. But our passion to understand and get to the bottom of "what lies beneath", will probably help dig more.
Please take your own sweet time to read, and shoot me a query if needed.

Your article is the new Gita and Bible of DSG.
Moderators must consider giving this a 7 star rating.

I am overwhelmed to read this, thanks again

[Thad E Ginathom]

Excellent thread. As a VW fanboy who also likes automatic transmission for the city roads on which I do most of my driving, it would come as no surprise if I had chosen the TSI --- but I didn't. I chose the Polo GT TDI, as being at least slightly less risk in a car intended for long-term ownership.

So if a fanboy gets jitters, how is anybody else to feel?

Thank you for a very clear thread. It cleared up some of the mechanical magic for me. And, as a side issue, I was never clear about dual-mass flywheels before!

[anshumandun]

That's a great post! Thanks for sharing all this knowledge.

One question: Which DSG gearbox does the 2.0 TDI cars with 380 Nm torque use (like the Audi Q3)? I see that DQ200 can take upto 250 Nm and DQ 250 upto 350 Nm.

[vigneshkumar31]

I have always been intrigued by the DSG and loved reading through this. A thorough dissertation on the DSG. Investigated with enthusiastic rigour and systematic approach. It is such level of detail and information assimilation that makes Team bhp a repository of all things auto!

Congratulations on a well compiled report.

[Thad E Ginathom]

The "mechatronics" would be outside my understanding anyway, but the actual mechanics of the gearbox itself are actually simpler than I imagined As mentioned, this is not an automatic gearbox, it is an automatically-controlled manual gearbox, But it is a lot bigger than I thought. The concentric shafts/clutches is a clever idea.

I thought mechatronic was a VW-marketing name --- but now I recall hearing it from others in engineering.

[Sankar]

Originally Posted by Thad E Ginathom

The "mechatronics" would be outside my understanding anyway, but the actual mechanics of the gearbox itself are actually simpler than I imagined As mentioned, this is not an automatic gearbox, it is an automatically-controlled manual gearbox, But it is a lot bigger than I thought. The concentric shafts/clutches is a clever idea.

I thought mechatronic was a VW-marketing name --- but now I recall hearing it from others in engineering.

Since these were not first a manual transmission and then converted to operate automatically these can only be classified as proper automatic transmissions; but a clutch based automatic transmission.

The truest forms of automatically controlled manual transmissions are the AMT (automated manual transmission) which are actually manual gearboxes converted to shift automatically. For example Maruti's AMT and other AMT in market. The reason these are cheap is because these are converted manual gearboxes which has a electronically controlled hydraulic (maybe electro mechanical in some) module which sits above the gearbox and actuate the clutch and also shift the gear from outside the box (not internally like a DSG).

Name mechatronics in enthusiast circles is usually associated with VW's DSG due to its infamous reliability concerns. But it is there in almost all modern automatics be it clutch based or torque converter based. These are a set of electronically controlled solenoid valves which open/close hydraulic circuits which operates clutches, brakes and make the gears change. In traditional torque converter application its called valve body now these are also electronically controlled.

[Sutripta]

Mechatronics was a term popularised by the Japanese. (Their universities first started offering courses on it).

One can have (admittedly limited) 'computers' which are not electronic.

Purely mechanical would be the original DAF. The Antonov never made it to production. (It would be interesting if someone could start a thread on the Antonov. It had an India connection, though very tenuous).

Regards
Sutripta

[Starfire]

Hats off to you JoshMachine. One of the most beautiful threads i've read on Team-Bhp. Your knowledge is at a different level.

Since you've been looking up at the rate of dsg faliures, I wanted to ask how has the situation been recently. I heard the DQ200 loaded cars sold since a couple of years back now use mineral oil instead of synthetic. Have the number of faliures of the gearbox since then gone down cause thats what I was told by multiple VW dealers when I bought my GT TSI last June.

[Sankar]

Originally Posted by Sutripta

Mechatronics was a term popularised by the Japanese. (Their universities first started offering courses on it).

Mechatronics goes beyond gearboxes and thats precisely why I said in enthusiasts circle (auto enthusiasts since this is an auto forum) it is usually associated with DSG.

PS: In recent years the forum has strayed away from enthusiasts though.

[JoshMachine]

Originally Posted by Thad E Ginathom

Thank you for a very clear thread. It cleared up some of the mechanical magic for me. And, as a side issue, I was never clear about dual-mass flywheels before!

Glad you found this thread useful! Thanks for the wishes.
DMFs are easily a neglected lot. Since one tends to focus so much inside the gearbox that we can sometimes forget what's causing the trouble outside.

Originally Posted by anshumandun

That's a great post! Thanks for sharing all this knowledge.
One question: Which DSG gearbox does the 2.0 TDI cars with 380 Nm torque use (like the Audi Q3)? I see that DQ200 can take upto 250 Nm and DQ 250 upto 350 Nm.

Thanks anshuman! I just collated, assimilated and presented the information (albeit with some additional 2 cents of my own ) in a manner that I thought would make some sense.
For your query on the Q3 TDi, I think it is mated with the 7-speed DQ500 gearbox.

Originally Posted by vigneshkumar31

I have always been intrigued by the DSG and loved reading through this. A thorough dissertation on the DSG. Investigated with enthusiastic rigour and systematic approach. It is such level of detail and information assimilation that makes Team bhp a repository of all things auto!
Congratulations on a well compiled report.

Thank you, vignesh!

Originally Posted by Thad E Ginathom

I thought mechatronic was a VW-marketing name --- but now I recall hearing it from others in engineering.

Originally Posted by Sutripta

Mechatronics was a term popularised by the Japanese.

Originally Posted by Sankar

Mechatronics goes beyond gearboxes and thats precisely why I said in enthusiasts circle (auto enthusiasts since this is an auto forum) it is usually associated with DSG.

Indeed, the term "mechatronics" has it's origins outside of the VW stables.
I was in two minds whether to go into the history of this word in my original thread. Anyway, the below image probably sums it up nicely:-



To propagate and enable wider adoption of this concept/technology, VW India helps Indian students to participate in an Apprenticeship Program (link for details)

Originally Posted by Starfire

Hats off to you JoshMachine. One of the most beautiful threads i've read on Team-Bhp.

Thanks Starfire!

Since you've been looking up at the rate of dsg faliures, I wanted to ask how has the situation been recently. I heard the DQ200 loaded cars sold since a couple of years back now use mineral oil instead of synthetic. Have the number of faliures of the gearbox since then gone down cause thats what I was told by multiple VW dealers when I bought my GT TSI last June.

Yes, you heard it right - infact, the change of oil from synthetic to mineral was done close to 5 years ago. You can check out the "Failures" section for specific details, if you want. Since the change, VW claims that the number of failures has drastically gone down.
Speaking of my own experience, my Vento bought in Sept'15 has the same gearbox and there have been no issues for the past 60,000-odd km (touchwood).

[Paleo]

My GT has had software updates at every service. But it always seems to be designed for spirited driving even in "D". Is there a version of the software, that I can ask for - that would help me with gear shifts suited for sedate driving? Or thats not a possibility?