[gthang]

Originally Posted by SS-Traveller

Sarcasm has no place here.

My first post in this thread:

Originally Posted by gthang

The DSG automatic is essentially an automated "manual gearbox" with 2 clutches, right?

If I was driving a "manual gearbox", I would not wait at the red light in gear with the clutch engaged, automated or not.

Cheers.

Your reply:

Originally Posted by SS-Traveller

Huh??! Now that's a new way of looking at things! Someone must've missed something when designing the DSG 'box and writing its user manual!

4 pages later, your reply on same:

Originally Posted by SS-Traveller

From .anshuman's post of the owner's manual, it is quite clear that the risk of overheating is very much there, hence point #3 above may well be true - that DSGs overheat, and the mechatronics is somehow damaged as a result.

If the mechatronics module is indeed being damaged due to overheating (as has been explained to me, this happens while driving in stop-start crawling traffic with the shift always in 'D'

So, who started with the sarcasm?
Any change in your point of view?

Originally Posted by V-16

Stop reading between the lines for content that is absent.

Also you contradict yourself. You say yopu are thankful to be a member on team bhp but also believe that we are a bunch of yes men happily agreeing to some post made by "Senior members" even if it is not in the right direction(i have not understood who these are and what you were trying to say). Also you do not confirm with the majority here. So what exactly are you thankful of being on this forum for?

This is classic. Please read my original line again, and see how you have read between the lines. Thanks for making the words bold so you show how you did it. Epic.

Originally Posted by V-16

I seriously doubt if anyone except you, have a chimera about me having ever even mention, leave alone profess about my being an authority on the subject or ANY subject on this forum or elsewhere?

Sounds pretty authoritative to me:

Originally Posted by V-16

You drive the DSG like any other automatic.

Originally Posted by V-16

Absolutely, i respect that, and you should too. Thgis could have been a healthy discussion, only you chose to attack the victims with your thoughts.

Please explain how I pulled this off?

Originally Posted by V-16

You're hilarious. Where did physics come in from?

Physics has always been there. You just havent seen it yet.

Originally Posted by V-16

im begging you again, show me

You can stop begging. If you want to know what or how I felt about the subject, just turn back the pages, and read posts 38, 48, 51, and 63. It's just nonsense jibber jabber after that.

See if you can source a chill pill as well. Looks like there is a deficiency.

Cheers.

[V-16]

Originally Posted by gthang

This is classic. Please read my original line again, and see how you have read between the lines. Thanks for making the words bold so you show how you did it. Epic.

You're Welcome!
Now everyone can see. I dont need to read it again. Its comforting to know that my grasp of understanding what is expressed is quite satisfactory, given the fact that i was unable to keep awake during classes, ive done quite well, dont you agree?

Regarding the lines i made bold...see below....Refrence to context

Originally Posted by gthang

Saga will continue till someone with a lot of "Seniority" posts some words of wisdom so the masses have a mantra to chant. Seemed to have worked wonders on the anti-Skoda campaign.
Cheers.

Sounds pretty authoritative to me:

What?? This?? Saying that i never said im authoritative, is authoritative? Are you for real??!!

Please explain how I pulled this off?

I dont know, you tell me, you seem to be the pro!!

Physics has always been there. You just havent seen it yet

Obviously, since i was the one could not keep awake!!

You can stop begging. If you want to know what or how I felt about the subject, just turn back the pages, and read posts 38, 48, 51, and 63.

Dont flatter yourself until you tell us the magic mantra for driving a DSG without ever having owned one. Im not begging you to know how you feel.......But the burning question is.... do you know how a DSG feels??

It's just nonsense jibber jabber after that.

Obviously, since you chose to drift towards a tangent and went into the "My Way or The Highway" syndrome and the I v/s the rest of you mode.

See if you can source a chill pill as well. Looks like there is a deficiency.
Cheers.

No worries mate, im cool and can be way cooler. Depends on the attitude of the person im corresponding with.

[SS-Traveller]

Originally Posted by gthang

So, who started with the sarcasm?
Any change in your point of view?

There is no sarcasm there, no personal comment either. An automatic gearbox is expected to be driven like one. If the DSG needs to be driven differently, I (and a lot of other people) want to know. .anshuman's reproductions of the owner's manual clarified some things that I was not aware of personally, and obviously changes my POV regarding DSGs to an extent. I have already stated earlier that I do not own a DSG and have only driven it a few times, and that too, exactly like any other autobox. I have not been aware that there is a trip mechanism built into the DSG once it overheats - that might lead us to conclude that overheating is a known & frequent issue with the DSG, unlike any other gearbox commonly available.

Originally Posted by gthang

It's just nonsense jibber jabber after that.
See if you can source a chill pill as well. Looks like there is a deficiency.

You obviously enjoy baiting other members on a forum with your jibber jabber. And you are also obviously overdosing on chill pills. Could we please remain on topic? If you have anything substantial to further contribute, please do. Otherwise do not deviate by posting counter-remarks about each individual here or beating the proverbial drum about your own great achievements in engineering school / college.

Originally Posted by V-16

...given the fact that i was unable to keep awake during classes, ive done quite well, dont you agree?
...
Obviously, since i was the one could not keep awake!!

........

[ajmat]

Note from Mod

OK guys, stop the bickering and lets get back onto topic about the DSG's and drving techniques.

[Aroy]

Here is what I can gauge from all the discussion

. DSG is a dual clutch system Each clutch engages an alternate set of gears - 1,3,5,(7) and 2,4,6,(8)
. At a time one clutch is engaged while the other is slipping, waiting to be engaged.
. The slipping clutch can contribute to the wear and tear of the DSG internals, as well as build up heat.
. While stopped, both the clutches are slipping, generating even more heat.
. The clutch slippage and the resultant heat build up, can result in heat related failure. This necessitates monitoring of the oil temperature in DSG box. At very high temperature, as a precaution the box is disengaged to prevent failure.
. All the electronics, hydraulics and mechanical parts are there in one sealed unit. Failure in any one component means the unit is out of commission.

So unlike the conventional Torque Converter based Automatic Gear Shift, DSG is not only more complicated, but has a built in source of heat, which under adverse ambient temperatures, coupled with extended idling while in gear can result in temperatures high enough to ruin the box.

Thus the driving techniques of DSG box cannot imitate that of a conventional torque converter, but should take into account the fact that though the box gives lightning fast shifts, the slipping clutches are its Achilles Heel, and due consideration should be given to these while driving (or rather while idling in gear at a traffic light)

To answer the Topic - Yes we are driving the DSG equipped cars wrong. The wrong part is in extended idling periods associated with heavy urban traffic. For any period where extended idling is anticipated, the gear box should be shifted to neutral (I know this reduces the major advantage of an automatic gear shift, but that is how the box is designed), if you want the gear box to last the life time of the car.

I hope that the current limitations will be overcome once better materials and better cooling is available, till then we have to bear with the limitation of the design to enjoy the DSG.

[anandpadhye]

Originally Posted by Aroy

. At a time one clutch is engaged while the other is slipping, waiting to be engaged.

I think the clutches slip only when they must. So when one clutch is engaged, the other is not necessarily slipping, it can be completely disengaged - in fact it will be disengaged as long as it can be. Hence from wear and tear point of view, I do not think DSG is going to be worse than MT. In fact , it will be a little better than MT, because slip is optimized.

Of course, during idling, if DSG is left in D then sure it will do worse than an MT because an MT driver mostly will shift to N during such idling.

That's about slipping of the 2 clutches - IMHO.

However, driving wrongly is still not an acceptable statement. I would rather say that future DSG's will automatically shift to N whenever they can or should. So the product should/will improve to maintain driving style (designated as "automatic" ).

[Swanand Inamdar]

Though shifting to N while in idle mode, negates the whole purpose of driving an AT, I guess for longetivity, thats a better practise to follow.

Till someone from Skoda does solve this riddle, thats what I would be doing.

[n.devdath]

Originally Posted by Aroy

To answer the Topic - Yes we are driving the DSG equipped cars wrong. The wrong part is in extended idling periods associated with heavy urban traffic. For any period where extended idling is anticipated, the gear box should be shifted to neutral (I know this reduces the major advantage of an automatic gear shift, but that is how the box is designed), if you want the gear box to last the life time of the car.

Seems to be well summed up but I wish we could get someone from Skoda or in the DSG business like BW to whet it.


Also, what needs to be further realised and understood is the irrepairable nature of these boxes which is not acceptable.

[.anshuman]

Originally Posted by Aroy

Here is what I can gauge from all the discussion


. While stopped, both the clutches are slipping, generating even more heat.

I disagree with your conclusion. Where did you find this? The owner's manual says it is OK to keep the in D with brakes pressed when waiting at an intersection. For any Automatic you wouldn't keep the brakes pressed for very long duration(example: waiting for someone).

Also, if the gear is engaged, it does not mean the clutch is slipping. DSG is smart enough not use half clutch while at rest. Speaking in MT language, at rest gear is engaged but clutch is also pressed when brakes are pressed.

Ever heard of clutches failing in DSG, the clutch life is much much longer than MT cars. There is a certain issues with 7 speed DSG, which the manufacturer are not disclosing, possibly the reason for very high rate of DSG failure in Superb 1.8 TSI 7 speed dry type DSG.

[Aroy]

Here is what Volkswagen has to say about DSG

http://www.volkswagen.co.uk/technolo...rivetrains/dsg

"Two independent gearbox units make up the DSG. With dual-clutch technology - two clutches in a common housing - both gearboxes are connected under load to the engine in turn, depending on the current gear, via two drive shafts. Clutch 1 serves the first gearbox unit with 1st, 3rd, 5th 7th and reverse gear and clutch 2 the second gearbox unit with 2nd, 4th and 6th gear. An output shaft that applies the torque to the driven wheels via the differential gear is assigned to each gearbox unit."

It stands to reason that if the engine is running and there is no neutral to decouple the engine from transmission, the clutches are all that connect the two. As there are two clutches and only one is engaged, the other must be disengaged and slipping (how ever slightly).

Regarding clutches, these are inside the DSG housing and not separate entities as in a manual car, hence we would not know whether the clutch failed, or due to overheating caused by slipping clutches other components failed. There is sufficient evidence that the failure is primarily due to over heating, and there is no other component in the DSG apart from clutches which can generate heat.

[.anshuman]

^^ But where is it mentioned that with brakes pressed in D mode and the car is stationary the clutch plates with be slipping all the time?

[V-16]

I think we are going off the topic here. The thing that fails here is the MEchatronic box, not the clutches nor the gearbox.
In my 6 speed Laura diesel, the shifting went haywire and in my 7 Speed Superb one morning the gear lever just refused to come out of the P position. Was fine when it was parked at night. The day before, i only drove to a friend's house for dinner which is 3 km away, no traffic nothing. Also stayed there for at least three hours and drove back, again no traffic at all, no inclines, declines etc. Parked the car and in the morning it just refused to come out of P mode. It refused to start, nothing would happen when the key is turned. No cranking even. The P was flashing. i was told thats a mechatronic problem and that the parking mode was not being recognized by the system. So the theory that stop and go traffic etc etc caused the clutch to slip does not apply.

I also read on another forum that since the oil heats up, it destroys/melts the plastic housing and destroys the M box. Nonsense. Both my boxes looked immaculate from the outside and the inside (the housing). The Laura box was repaired and the Superb's was changed. Even if the heating causes this, why hasnt Skoda thought of getting a plastic which can withstand higher temperatures or changed the housing from plastic to some other material? I dont even buy the plastic melting theory.

Actually what causes the box to fail is unknown so us discussing that the clutch slips etc because of the load does not make sense till we link the failing of the M box to it.

The only people who can answer this is Skoda and i hope the auto magazines have enough courage to ask them this question directly.

They know its a defective box, thats why the newer Polos and Ventos do not come with a DSG.

[ACM]

Originally Posted by Aroy

To answer the Topic - Yes we are driving the DSG equipped cars wrong. The wrong part is in extended idling periods associated with heavy urban traffic. For any period where extended idling is anticipated, the gear box should be shifted to neutral (I know this reduces the major advantage of an automatic gear shift, but that is how the box is designed), if you want the gear box to last the life time of the car.

Driving technique can vary slightly from car to car, but to me the driving technique for a car is what is mentioned in the user manual. The Laura DSG AT user manual does not speak about the above way of driving hence we can't be driving the wrong way. If the gear box required to be moved to N during heavy urban traffic or if there was a limit to the period of time it can be kept in D mode with bakes pressed it should have been specified of actually should have automatically moved to N after the period expired.

Hence cannot agree that the driving technique is wrong as the maufacturer is has not mentioned that one must drive in this particular manner.

Also as mentioned by V16 above, the box failing is the mechatronic unit.

Also besides like mentioned by Anshuman above I too can't really see it as a clutch slipping all the while while one is engaged or as both slipping while none are engaged. To me they are both simply disengaged. The logic mentioned could be correct but it still does not really pertain to the mechatronic unit or the driving style.

Irresprective the units though introduced first in India in the Laura have been in Audis and VW's globally much prior and if they required a different way of driving am sure that would have made it's way to the user manual.

[VeyronSuperSprt]

There has been a problem with a certain batch of Superb DSG boxes some years ago on account of a sharp fluctuation in the electricity output on the assembly line in the factory which damaged the mechatronics which control the gearbox and not the gearbox itself. This has led to various problems being faced by owners of Superbs produced out of that batch.

[Sutripta]

Originally Posted by Aroy

. At a time one clutch is engaged while the other is slipping, waiting to be engaged.
. The slipping clutch can contribute to the wear and tear of the DSG internals, as well as build up heat.


......


I hope that the current limitations will be overcome once better materials and better cooling is available, till then we have to bear with the limitation of the design to enjoy the DSG.

Is there a difference between holding a clutch at its friction point (aka bite point) and fully disengaged?
During normal running, what should be the engagement status of the inactive clutch?

What's preventing VW putting in an oil cooler? (Lots of conventional auto transmissions have it after all.) Could it be because that is actually not the cause?

Have you ever approached any of the older Indian companies with a warranty issue. (Say Exide). Deja Vu?

Regards
Sutripta