DSG servicing intervals

[Maverick]

What??? 240nm limit? Is this right? I thought the DSG7 could handle at least 320nm.

It probably can, VW always under-rate their gearboxes. The DSG 6 speed on the GTI is good for 500+nm despite being officially good for 350nm. VW themselves ran them in the Nuremberg 24 hour race pumping out over 550nm without any failures and there are some with 600+nm going through them without failures.

[Transporter]

What??? 240nm limit? Is this right? I thought the DSG7 could handle at least 320nm.

The 7sp DSG has much less oil in it, that's why it has reduced torque.

[logger]

What??? 240nm limit? Is this right? I thought the DSG7 could handle at least 320nm.

It probably can, VW always under-rate their gearboxes. The DSG 6 speed on the GTI is good for 500+nm despite being officially good for 350nm. VW themselves ran them in the Nuremberg 24 hour race pumping out over 550nm without any failures and there are some with 600+nm going through them without failures.

Of course it can handle more torque. You're both missing my point here. The designers have restricted it to 250Nm to prolong its life. There is an article floating around the web somewhere quoting one of the designers saying just this. Further this Nm limit is not to prevent the DSG from breaking. It is to prolong the life of the clutches to whatever VW deem to be the vehicle life so they never have to service the twin clutches. I am just extrapolating from this and from what I can see in erWin to wonder if the same applies to the DSG7 as a whole. ie It does not require routine servicing like the DSG6 does? Will quote said article as soon as I can find it again.

Now transporter, tying the DSG torque to Oil quantity sounds like a real Furphy to me.

[Transporter]

Now transporter, tying the DSG torque to Oil quantity sounds like a real Furphy to me.

I'm all ears.

edit: That maybe give you some idea how much of torque you can put in 7sp dry clutch DSG.

http://www.automotiveproductsfinder.com/Articles/AR2008/FEB/AR-04.asp

[logger]

OK here you go ... a Furphy = "a mixture of truth and untruth".
I thought perhaps you were pulling our legs extolling a relationship between torque & oil Quantity, hence a Furphy. Would it not be more related to the strength vs required life of various components?

Thanks for the link. Thats a good article explaining differences in how the DSG7 & DSG6 function BTW. Ties in with erwin saying to remove the mechtronics unit and send it off for exchange leaving oil in it, when it needs attention. WRT the article "...maybe give you some idea how much of torque you can put in 7sp dry clutch DSG" it just says 250 Nm like every other article so does not help much as to why that limit is in place.

Anyone got any thoughts on the DSG7 service interval - is it 60,000km or not? I think Not.

[Transporter]

OK here you go ... a Furphy = "a mixture of truth and untruth".
I thought perhaps you were pulling our legs extolling a relationship between torque & oil Quantity, hence a Furphy. Would it not be more related to the strength vs required life of various components?

Thanks for the link. Thats a good article explaining differences in how the DSG7 & DSG6 function BTW. Ties in with erwin saying to remove the mechtronics unit and send it off for exchange leaving oil in it, when it needs attention. WRT the article "...maybe give you some idea how much of torque you can put in 7sp dry clutch DSG" it just says 250 Nm like every other article so does not help much as to why that limit is in place.

Anyone got any thoughts on the DSG7 service interval - is it 60,000km or not? I think Not.

Reduce torque has a lot to do with dry clutches (hence much less oil used), I think that if you start to run much more than 250Nm torque through the 7SP DSG you will wear out clutches very soon. I might be wrong but only time will tell.

[gerhard]

The 7sp DSG has much less oil in it, that's why it has reduced torque.

I also think that is rubbish. The lower oil quantity is purely because the clutch has no oil requirement, and the mechatronics has its own separate sump.

The reduced torque is probably because "the rest of the transmission was designed to be that much more compact, so that it could be used even on small cars the size of the Polo."

So it has reduced torque because it is smaller.....

It's interesting that the 7 speeder is in the new T5 with 400nm and will be in Amorak with 400nm.....clearly the variant in those vehicles will be bigger than the baby one.

[logger]

Lubrizol who make Oil to go in DSGs have made this site called Dual Clutch Transmission Facts. They maintain that
"Wet clutches running in an oil bath or mist are used for higher torque applications where there is more energy to handle and more heat to dissipate. "
Wet Clutch or Dry Clutch?
Wet vs. Dry
So you can infer whatever you like from all of this. But seemingly the DSG7 is used in lower torque applications to avoid heat build up in the clutches under high loads. So it is the clutches that are the weak link.

How does this sound:
Dry clutches cannot dissipate heat as effectively as wet clutches, this is why the 7sp DSG OAM is used in lower Torque applications.

BTW, I read and someone can probably confirm, there is no OEM launch control option envisiaged for the DSG7 OAM. Again I would assume this is to prevent excessive heat build up and prolong the life of the clutches.

Does the 7 speeder 400nm have a wet clutch?

[Transporter]

I also think that is rubbish. The lower oil quantity is purely because the clutch has no oil requirement, and the mechatronics has its own separate sump.

The reduced torque is probably because "the rest of the transmission was designed to be that much more compact, so that it could be used even on small cars the size of the Polo."

So it has reduced torque because it is smaller.....

It's interesting that the 7 speeder is in the new T5 with 400nm and will be in Amorak with 400nm.....clearly the variant in those vehicles will be bigger than the baby one.

Well, you think wrong than. Dry clutches will not handle much bigger torque then 250Nm. That's why it is not used in Golf 6 2.0L TDI. If you have any other information can you give us some references, please?

[gerhard]

Well, you think wrong than. Dry clutches will not handle much bigger torque then 250Nm. That's why it is not used in Golf 6 2.0L TDI. If you have any other information can you give us some references, please?

First it was the lower oil capacity that made the box weaker, now it's because of the clutches. Make up your mind.

Then explain how the T5/Amorak 7-speeder can handle 400nm, with dry clutches.

I'd guess that the box is bigger, and maybe the clutches are bigger diameter. And it will have more oil then the "baby" 7speeder, but will still have less than the 6speeder with wet clutches.

Your theory about oil volume being related to torque handling is just wrong.

[Transporter]

First it was the lower oil capacity that made the box weaker, now it's because of the clutches. Make up your mind.

Then explain how the T5/Amorak 7-speeder can handle 400nm, with dry clutches.

I'd guess that the box is bigger, and maybe the clutches are bigger diameter. And it will have more oil then the "baby" 7speeder, but will still have less than the 6speeder with wet clutches.

Your theory about oil volume being related to torque handling is just wrong.

I thought that were talking about 7 Sp DSG transmission as is in Golf 6 not in Amorak or T5. I don't want to argue with you or anybody and I don't think that it's my theory, therefore I don't have to make my mind to give you explanation why there is only 250Nm available.

I’m sorry if you feel that I misled you in anyway it wasn’t my intend.

[gerhard]

I thought that were talking about 7 Sp DSG transmission as is in Golf 6 not in Amorak or T5. I don't want to argue with you or anybody and I don't think that it's my theory, therefore I don't have to make my mind to give you explanation why there is only 250Nm available.

I’m sorry if you feel that I misled you in anyway it wasn’t my intend.

I was not misled when you stated "The 7sp DSG has much less oil in it, that's why it has reduced torque." That's why I replied to clear up the situation.

But many others reading the forum might believe it, and start spreading it around and before you know it, everyone thinks it's true.

So, in summary -

1) The 6 speed DSG with oil filled clutches has been around since 2004, and can officially handle 350nm, unoficially 500+ has been fed through it with no breakages. The higher 500+ applications are likely to have uprated clutches. These transmissions require oil changes every 60,000k or in severe applications more often. Early versions had oil coolers which were dropped around 2007. I have recently seen this transmission out of a car, and I was surprised at how big it is. Is also used in V6 R32 AWD cars, and in the case of APMitchell's R32 Turbo is handling some extreme power and torque.

2) The newer (around 2008 ) 7 speed DSG has dry clutches, self-contained mechatronics, and separate oil in the gear sump, which is billed as "lifetime service". Theoretically this means never to be changed, in reality a change at 100 or 120k might be advisable. This transmission is oficially rated at 240 or 250nm and is smaller than the 6 speeder for use in smaller cars such as Polo, but I think is being used in quite a few larger cars to replace the 6 speeder, such as Golf VI, Skoda, Jetta with the 1.4 engines. Tunes on these are taking the torque well beyond the rating.

3) An even newer version of the 7 speed DSG is being used in Amorak and T5, with engines fitted to those vehicles rated at 400nm. The transmission has dry clutches and is a beefed up version of 2), presumably it will be physically larger than the 240nm version. Maximum torque handling is possibly similar to the Audi S-Tronic 7 speeder which is officially 550nm. If that twin turbo diesel finds its way into Passats or Golfs as an R variant they will get the trannie too

[logger]

...and to further summarise and cap of the very reason for me bringing this thread up again in the first place...

I believe we have established that There is no published service interval for the DSG7 OAM.

[Transporter]

First it was the lower oil capacity that made the box weaker, now it's because of the clutches. Make up your mind.

Then explain how the T5/Amorak 7-speeder can handle 400nm, with dry clutches.
I'd guess that the box is bigger, and maybe the clutches are bigger diameter. And it will have more oil then the "baby" 7speeder, but will still have less than the 6speeder with wet clutches.

Your theory about oil volume being related to torque handling is just wrong.

Naah, I let you to google it out.

[Bug_racer]

Have any of you actually seen the clutch thats in the 7speed ? Its not much bigger than whats in a 6n polo 1.6 !