Crank walk on Golf R?

[gingercabrio]

He's in Sweden, so yes.

Never underestimate the migratory patterns of the African swallow.

 

[RolfG]

He's in Sweden, so yes.

I thought crank walk was more likely on certain aftermarket clutches? assuming people have figured out what to avoid by now

They all use the same ea888 engine... it makes no difference which one you choose. There isnt enough data to speculate on anything, if specific models are more susceptible, etc.

All we know is extreme aftermarket clutches may play a part.

I'm in Swedanstan so you never know.

If you buy, lets say a Sachs 550nm. I guess the pressure must be a bit higher then a stock clutch and therefore increasing the risk slightly?
Have we seen anyone running that specific clutch failing?

 

[scrllock]

I'm in Swedanstan so you never know.

If you buy, lets say a Sachs 550nm. I guess the pressure must be a bit higher then a stock clutch and therefore increasing the risk slightly?
Have we seen anyone running that specific clutch failing?

I'd guess an OE+ like that would be fine. I think people have also moved towards clutchless starts which is supposed to help (definitely available via free public patches, requires a hardware solution for cobb, etc. last I knew).

 

[hans611]

Well its not exactly black and white like that, there isn't a certain point where the pressure plate is "too strong" and "causes crank walk".... The issue with the thrust bearing could still be primarily related to manufacturing, there just may be some other factors that worsen the problem...

We know for a fact it affects manual cars more than DSG cars. Also, as mentioned earlier, extreme aftermarket clutches may play a part as many of the people reporting crankwalk on manual cars have aftermarket clutches.
However, this could be a correlation, as people that add more power, tend to also upgrade the clutch....

What I take from it is for sure manual cars are more susceptible, therefore any stronger pressure plate than stock cannot be good but its such a small pool of data that you might as well not worry about it if you really want to upgrade....

Just if you can, be mindful when you start it, don't hold the clutch down longer than needed, dont hold the clutch down on intersections, when backing up etc... dont know if it will help but it cant hurt.

Edit: Honestly, I think this problem in the end has to do with oil starvation, maybe long term starvation in this case. So many MK7 problems eventually can be explained that way. Check your oil constantly. Also, don't know if it will matter, we don't have an oil pressure sensor so I cant tell anything, Im just talking BS here, but maybe let it idle a min or 2 in the mornings after starting so the crank bearings are nice and oiled before backing up, etc...? Or are the crank bearings basically pressurized with oil instantly?

 

[RolfG]

I'd guess an OE+ like that would be fine. I think people have also moved towards clutchless starts which is supposed to help (definitely available via free public patches, requires a hardware solution for cobb, etc. last I knew).

Well its not exactly black and white like that, there isn't a certain point where the pressure plate is "too strong" and "causes crank walk".... The issue with the thrust bearing could still be primarily related to manufacturing, there just may be some other factors that worsen the problem...

We know for a fact it affects manual cars more than DSG cars. Also, as mentioned earlier, extreme aftermarket clutches may play a part as many of the people reporting crankwalk on manual cars have aftermarket clutches.
However, this could be a correlation, as people that add more power, tend to also upgrade the clutch....

What I take from it is for sure manual cars are more susceptible, therefore any stronger pressure plate than stock cannot be good but its such a small pool of data that you might as well not worry about it if you really want to upgrade....

Just if you can, be mindful when you start it, don't hold the clutch down longer than needed, dont hold the clutch down on intersections, when backing up etc... dont know if it will help but it cant hurt.

You are right. It's hard to tell what the cause is. One thing is for sure, I can't tell my wife to do all this things when she's driving. Even though the risk seems pretty small I will probably worry to much. It's a bit like the crank hub issue on the S55 engine when tuning.

Just a guess from the knowledge I have about material science. I would say it's more likely that the number of clutch activations could play a larger role than the time you hold the clutch in those scenarios you mentioned. But I could be missing something.

 

[hans611]

Maybe how fast the clutch is pulled back, the initial jolt on the crank and pressure to the thrust bearing...?
A common mod is to delete the clutch "swirl valve" on the clutch line and the "delay valve" on the line bleeder block....
Those mods allow the clutch engagement to be faster and more aggressive...... that certainly can't be helping?

 

[gingercabrio]

I'm in Swedanstan so you never know.

If you buy, lets say a Sachs 550nm. I guess the pressure must be a bit higher then a stock clutch and therefore increasing the risk slightly?
Have we seen anyone running that specific clutch failing?

The pressure is a bit higher, of course. In theory, Sachs knows what axial loading is acceptable for the Mk7 thrust bearings, because they also supplied the original clutch. Do they care? Not necessarily. Is it possible the stock clutch is so fragile because Sachs couldn't provide a clutch system capable of holding the required torque without exceeding the maximum axial loading on the crankshaft? Absolutely.

I'll maintain that the only unimpeachable solution is to have the middle lower main cap machined to accept an extra two thrust washers, which is the standard configuration that Volkswagen deviated from in the mid 2000s in order to reduce cost and running friction. A shop in Canada has done this work for about $1000 on top of the price of a clutch job. There is a Swedish forum in which an individual describes doing this work themselves. To revisit the dead horse, I'd say this is equivalent to living on a planet with no coconuts.

Failing that, it generally holds that a clutch rated for more torque will impart a greater axial load on the crankshaft. I'd consider the Sachs 550nm clutch the safest option, especially in conjunction with frequent changes of quality oil with a good HTHS rating, which ensures the thrust washer will stay lubricated. If you can bypass the interlock to reduce cold start wear on the bearing group, even better. That said, there is one report on Vortex of crankwalk with the 8J TTRS clutch, which is rated for even less torque than the Sachs aftermarket unit for the Mk7. For all we know, that car might've had a failure even with the stock clutch, which has happened, even with DSGs. And no, the TTRS thrust washers aren't interchangeable with those in the EA888, even though the five cylinder also only uses two.

Unless you have the lower main cap machined, I don't think you can fit an aftermarket clutch without having to live in Florida. And if you go SMF, you're at least on the beach. But I'd said it's only with the really stiff aftermarket clutches, especially the DKM parts, that you are standing under a coconut tree in a hurricane.

 

[RolfG]

Maybe how fast the clutch is pulled back, the initial jolt on the crank and pressure to the thrust bearing...?
A common mod is to delete the clutch "swirl valve" on the clutch line and the "delay valve" on the line bleeder block....
Those mods allow the clutch engagement to be faster and more aggressive...... that certainly can't be helping?

Yeah, perhaps. It could be that cyclic load that causes this issue (fatigue). This could cause failure even under the theoretical max load. But I know to little about the actual load the transmission causes to say anything tbh. But in general fatigue (caused by a cyclic load) is a common cause of failure so my guess would be that it's the main cause here.

The pressure is a bit higher, of course. In theory, Sachs knows what axial loading is acceptable for the Mk7 thrust bearings, because they also supplied the original clutch. Do they care? Not necessarily. Is it possible the stock clutch is so fragile because Sachs couldn't provide a clutch system capable of holding the required torque without exceeding the maximum axial loading on the crankshaft? Absolutely.

I'll maintain that the only unimpeachable solution is to have the middle lower main cap machined to accept an extra two thrust washers, which is the standard configuration that Volkswagen deviated from in the mid 2000s in order to reduce cost and running friction. A shop in Canada has done this work for about $1000 on top of the price of a clutch job. There is a Swedish forum in which an individual describes doing this work themselves. To revisit the dead horse, I'd say this is equivalent to living on a planet with no coconuts.

Failing that, it generally holds that a clutch rated for more torque will impart a greater axial load on the crankshaft. I'd consider the Sachs 550nm clutch the safest option, especially in conjunction with frequent changes of quality oil with a good HTHS rating, which ensures the thrust washer will stay lubricated. If you can bypass the interlock to reduce cold start wear on the bearing group, even better. That said, there is one report on Vortex of crankwalk with the 8J TTRS clutch, which is rated for even less torque than the Sachs aftermarket unit for the Mk7. For all we know, that car might've had a failure even with the stock clutch, which has happened, even with DSGs. And no, the TTRS thrust washers aren't interchangeable with those in the EA888, even though the five cylinder also only uses two.

Unless you have the lower main cap machined, I don't think you can fit an aftermarket clutch without having to live in Florida. And if you go SMF, you're at least on the beach. But I'd said it's only with the really stiff aftermarket clutches, especially the DKM parts, that you are standing under a coconut tree in a hurricane.

That sounds likely regarding the Sachs theory. Could explain why VW never fixed this issue by upgrading the clutch.
"I don't think you can fit an aftermarket clutch without having to live in Florida". Do you mean that it's a risk going with an aftermarket clutch no matter the clutch if you haven't fixed the bearings, even the 550Nm?

 

[gingercabrio]

"I don't think you can fit an aftermarket clutch without having to live in Florida". Do you mean that it's a risk going with an aftermarket clutch no matter the clutch if you haven't fixed the bearings, even the 550Nm?

It's a risk even with the stock clutch.
With an aftermarket one, of any kind, you are closer to the coconuts.

Also, from what I've seen, the thrust washers are usually found in the oil pan intact after these episodes. That would indicate the problem isn't a structural failure of the bearing, but simply a matter of it wearing down. I suspect there was either a metallurgy or coating issue with the F part, and perhaps it was resolved with the N part, which is still used in the Mk8. There is a surprising number of revisions of this part, mostly used in the EA888 family, although the 8J TTRS engine uses a different revision (K) of the same part number. Before F, H was used in the Gen 3 until 2015, and before that, D was used in the Gen 2, among other VW group products. Interestingly, there is a bespoke variant for the Audi A6 (P), which has a distinctive red coating. It's hard to say at this point whether the F part is more failure prone or there simply aren't enough miles on the N revision cars yet to see lots of issues.

 

[Ezekiel81923]

Stay in the northern half of Florida and you won't have to worry about coconuts

Not sure how that translates to crank walk in this metaphor but you'll live longer.

 

[RolfG]

This forum is nuts.

I think my question have been answered. A tuned manual is not the car for me. A DSG Cupra ST it shall be.

 

[Cuzoe]

This forum is [coco]nuts.

I think my question have been answered. A tuned manual is not the car for me. A DSG Cupra ST it shall be.

 

[RolfG]

It's a risk even with the stock clutch.
With an aftermarket one, of any kind, you are closer to the coconuts.

Also, from what I've seen, the thrust washers are usually found in the oil pan intact after these episodes. That would indicate the problem isn't a structural failure of the bearing, but simply a matter of it wearing down. I suspect there was either a metallurgy or coating issue with the F part, and perhaps it was resolved with the N part, which is still used in the Mk8. There is a surprising number of revisions of this part, mostly used in the EA888 family, although the 8J TTRS engine uses a different revision (K) of the same part number. Before F, H was used in the Gen 3 until 2015, and before that, D was used in the Gen 2, among other VW group products. Interestingly, there is a bespoke variant for the Audi A6 (P), which has a distinctive red coating. It's hard to say at this point whether the F part is more failure prone or there simply aren't enough miles on the N revision cars yet to see lots of issues.

Someone mentioned that all Cupras have the N part. Even for 2016 models. Is this correct?
So perhaps the Cupra is not affected

 

[bentin]

Someone mentioned that all Cupras have the N part. Even for 2016 models. Is this correct?
So perhaps the Cupra is not affected

Well, I can think of one way to find out. Report back...

 

[ChrisMk77]

Someone mentioned that all Cupras have the N part. Even for 2016 models. Is this correct?
So perhaps the Cupra is not affected

Tjena Roffe

Just to confuse even more, dsg cars can have crankwalk to and of the ones I have seen the common issue was flywheel imbalance on newer DQ381.

Cupras has had every revision of parts the same as R/S3.