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Crank walk / class action (we need to get together)

ArrgRer

New member
Location
USA
Car(s)
Mk7 VW Golf R
What would be the minimum required work to install the thrust bearings? Remove trans and install new bearings with the engine mounted? Or will you need to pull the engine completely?




Man that sucks, especially with the OEM DMF, no one is safe. I do find the clutch issues you had before it happened interesting and wonder how/if a failing thrust bearing would cause it to feel like a failing slave cylinder. Crankwalk always seems to sneak up without warning, which is why Im interested in this.

I did exchange an email with the guys in the UK and they said it is possible to replace the thrust bearings with the engine in the car. I can't validate that from experience, but it seems possible. It looks like we would have to remove the crank pulley, lock the inner pulley to prevent timing slip, remove the lower timing cover, zip tie the timing chain to prevent moving, remove the oil pump pulley/chain, then drop the oil pump and its support frame that sits between the pan and block. That will expose the bearing caps. Remove the main bearing cap that contains the thrust bearings and it should be possible to push/rotate the half moon bearing out with a new bearing.

Regarding the clutch feel question, it makes sense now. Clutch pushes on flywheel which pushes on the crankshaft - if the crank moves outward due to missing bearing, then there's an extra 2mm of travel in the process. Then, it moves back inward and it all starts again. It "feels" like the slave cylinder is failing to return to its original position.

The problem is that this is a binary issue - it's all good until that bearing pops out of its location. Then it goes from fractions of a mm to 2mm instantaneously. There is no warning and it's not obvious enough when it does happen.
 

PerceivedShift

Autocross Champion
Location
Virginia
I did exchange an email with the guys in the UK and they said it is possible to replace the thrust bearings with the engine in the car. I can't validate that from experience, but it seems possible. It looks like we would have to remove the crank pulley, lock the inner pulley to prevent timing slip, remove the lower timing cover, zip tie the timing chain to prevent moving, remove the oil pump pulley/chain, then drop the oil pump and its support frame that sits between the pan and block. That will expose the bearing caps. Remove the main bearing cap that contains the thrust bearings and it should be possible to push/rotate the half moon bearing out with a new bearing.

Regarding the clutch feel question, it makes sense now. Clutch pushes on flywheel which pushes on the crankshaft - if the crank moves outward due to missing bearing, then there's an extra 2mm of travel in the process. Then, it moves back inward and it all starts again. It "feels" like the slave cylinder is failing to return to its original position.

The problem is that this is a binary issue - it's all good until that bearing pops out of its location. Then it goes from fractions of a mm to 2mm instantaneously. There is no warning and it's not obvious enough when it does happen.
Interesting, thanks. So do you think the thrust bearing fell out a few months ago when you initially felt the change in the clutch feel?
 

ArrgRer

New member
Location
USA
Car(s)
Mk7 VW Golf R
Interesting, thanks. So do you think the thrust bearing fell out a few months ago when you initially felt the change in the clutch feel?

Good question. Not sure. My brain was saying clutch hydraulic issue and never thought about crank walk. Only when I got a low oil pressure warning and some other codes did I start looking for this issue.
 

Kdubya

Go Kart Champion
Location
Florida
Car(s)
2017 GTI
@ArrgRer im curious to ask, what are your mods? How did you drive the car on a day to day basis?
 

ArrgRer

New member
Location
USA
Car(s)
Mk7 VW Golf R
@ArrgRer im curious to ask, what are your mods? How did you drive the car on a day to day basis?

It's a daily driver. 95k miles. Mods are Sachs performance clutch (@40k miles), VW OEM DMF, APR short shift kit and braided line, and JB1 with very mild tune on it. I drive it spirited, but within reason - never thrashed it. No race or autoX on it. Pretty benign stuff.
 

JerseyDrew77

Autocross Champion
Location
Virginia & NC
Car(s)
2016 TR GTI S 6MT
What would be the minimum required work to install the thrust bearings? Remove trans and install new bearings with the engine mounted? Or will you need to pull the engine completely?
I'd imagine the engine would have to be pulled.
That is the easiest way to do it.

I did exchange an email with the guys in the UK and they said it is possible to replace the thrust bearings with the engine in the car. I can't validate that from experience, but it seems possible. It looks like we would have to remove the crank pulley, lock the inner pulley to prevent timing slip, remove the lower timing cover, zip tie the timing chain to prevent moving, remove the oil pump pulley/chain, then drop the oil pump and its support frame that sits between the pan and block. That will expose the bearing caps. Remove the main bearing cap that contains the thrust bearings and it should be possible to push/rotate the half moon bearing out with a new bearing.

Regarding the clutch feel question, it makes sense now. Clutch pushes on flywheel which pushes on the crankshaft - if the crank moves outward due to missing bearing, then there's an extra 2mm of travel in the process. Then, it moves back inward and it all starts again. It "feels" like the slave cylinder is failing to return to its original position.

The problem is that this is a binary issue - it's all good until that bearing pops out of its location. Then it goes from fractions of a mm to 2mm instantaneously. There is no warning and it's not obvious enough when it does happen.
Yeah, you can do it while it's in the engine bay but it would be a major pain in the ass. It's just a lot easier to remove the engine and then work on the crankshaft and thrust bearings. I think the only failsafe solution would be to have a 360 degree thrust bearing.
 

GTIfan99

Autocross Champion
Location
FL
Knock on wood, I dodged the IMS bearing issue with a 986 S and 996. I'm hoping I dodge this bullet too.
 

ArrgRer

New member
Location
USA
Car(s)
Mk7 VW Golf R
That is the easiest way to do it.


Yeah, you can do it while it's in the engine bay but it would be a major pain in the ass. It's just a lot easier to remove the engine and then work on the crankshaft and thrust bearings. I think the only failsafe solution would be to have a 360 degree thrust bearing.

Spent some time this Saturday... it is not possible to get to the bearings without removing the transmission and transfer case. The main crank seal bolts go into the upper oil pan. The transfer case blocks access to the triple square that needs removed to drop the crank journal.

Obviously, at this point removing everything is the long term option.

What an absolute crap design from VW... a 2 dollar part costing thousands of dollars of repairs.
 

j255c

Go Kart Champion
Location
New York
Car(s)
2018 Golf R Manual
Spent some time this Saturday... it is not possible to get to the bearings without removing the transmission and transfer case. The main crank seal bolts go into the upper oil pan. The transfer case blocks access to the triple square that needs removed to drop the crank journal.

Obviously, at this point removing everything is the long term option.

What an absolute crap design from VW... a 2 dollar part costing thousands of dollars of repairs.
Not true. A shop in Canada does this routinely. They’re the only one apparently who can do this which is weird but they’ve done dozens. They machine a 360 thrust cap by dropping the oil pan.
 

ArrgRer

New member
Location
USA
Car(s)
Mk7 VW Golf R
I would like to see how they do it on this engine - seriously. The only way I can see would be to cut out the upper pan where the journal is and to make a custom triple square wrench to undo the side bolt holding the journal (which wouldn't be too hard). The issue is the two bolts that go into the side of the upper pan from the crank main seal requiring removal of the trans and flywheel. Here's a pic with the location of the journal circled:

1661256616224.png



Do you have the number of the shop in Canada by any chance? I would dearly like to talk with them if they have some trick to remove this upper pan. The new bearing is the easy part - it's getting to it.

Thanks.
 

j255c

Go Kart Champion
Location
New York
Car(s)
2018 Golf R Manual
I would like to see how they do it on this engine - seriously. The only way I can see would be to cut out the upper pan where the journal is and to make a custom triple square wrench to undo the side bolt holding the journal (which wouldn't be too hard). The issue is the two bolts that go into the side of the upper pan from the crank main seal requiring removal of the trans and flywheel. Here's a pic with the location of the journal circled:

View attachment 258907


Do you have the number of the shop in Canada by any chance? I would dearly like to talk with them if they have some trick to remove this upper pan. The new bearing is the easy part - it's getting to it.

Thanks.
They will not divulge their secrets i and many others have tried. Foreign Automotive is the name.
 
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