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

ArrgRer

Passed Driver's Ed
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

Passed Driver's Ed
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

Drag Racing 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

Passed Driver's Ed
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

Passed Driver's Ed
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

Drag Racing 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

Passed Driver's Ed
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

Drag Racing 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.
 

ArrgRer

Passed Driver's Ed
Location
USA
Car(s)
Mk7 VW Golf R
Finally have an update to this!

It is possible to do this with engine/trans in the car, but only if willing to cut out part of the mid pan. I decided to go this route given lack of other good options. Basically, dealer or shop would go with a new block and crankshaft - easily a $10k+ cost or 50% of the value of the car.

I'm sure some folks on here will cringe at the approach I took to this repair and that's fine. My rationale is that there's little to be lost by trying it - even if it fails, a new block/crank would be required. So, for about $200 and quite a bit of time waiting on parts, it's back on the road for this issue.

Here's the process I took:

1. Remove pan and plastic tray
2. Remove Oil Pump
2. Cut the 4 web of the mid pan that block access to the mid-journal cap:

1667158331024.png


3. Remove cap. Two bottom bolts and two that come in from the side of the block.

1667158382191.png


The side bolts are tricky, especially the back one. To get to the back one, loosen the bracket by removing the 3 bolts and rotating it up toward the passenger side:

1667158550019.png


Then, you need a very stubby 10mm triple square and a 3/8 flat driver (cheap from Amazon):

1667158693858.png


The front one is 12mm triple square and can be access by loosening the hoses and charge pipe stuff on the front of the engine.

4. Ship to UK to be machined and returned with additional bearings (this took 6 weeks due to some issues on their end - should have been about 3 weeks).

1667158957048.png


1667158982764.png


1667159038252.png


1667159059959.png


5. I removed plugs and spun by hand, then progressed to spinning with the starter motor. I remeasured the end play with a dial indicator and it's less than 0.2mm. There was some scoring on the crankshaft mating surface, but not too deep and it should bed into the bearing surface over time.

6. Buttoned it all up, added oil and started up no problem. Remeasured end play and no change. First drive went fine and no odd sounds unlike before.

Conclusions and notes on this endeavor...

It's a pretty crude approach and not for the faint of heart. Considering that I was looking at 50% of the value of the car to properly "fix", it was worth it to me to give it a shot - I have other cars to drive, so time wasn't an issue.

Also, if I had kept driving it like it was, this fix would not be possible as the wear on the crank, block, and cap would have been too great to accept a new bearing. I consider it borderline already, and had I known about this thrust bearing issue and diagnosing it earlier, the fix would be much better. The seemingly unrelated weird clutch not returning up was the symptom that really indicated the issue. And eventually a whining noise when depressing the clutch.

The bearing is 2mm thick when new - my worn bearing (clutch side) was wafer thin.

And, finally a nice fall shot:

1667160319108.png


Good luck out there and feel free to take what you will from my experience.
 

PerceivedShift

Autocross Champion
Location
Virginia
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. H
I wonder in their "secret" is cutting the mid pan like you did?!

Finally have an update to this!

It is possible to do this with engine/trans in the car, but only if willing to cut out part of the mid pan. I decided to go this route given lack of other good options. Basically, dealer or shop would go with a new block and crankshaft - easily a $10k+ cost or 50% of the value of the car.

I'm sure some folks on here will cringe at the approach I took to this repair and that's fine. My rationale is that there's little to be lost by trying it - even if it fails, a new block/crank would be required. So, for about $200 and quite a bit of time waiting on parts, it's back on the road for this issue.

Here's the process I took:

1. Remove pan and plastic tray
2. Remove Oil Pump
2. Cut the 4 web of the mid pan that block access to the mid-journal cap:

3. Remove cap. Two bottom bolts and two that come in from the side of the block.

4. Ship to UK to be machined and returned with additional bearings (this took 6 weeks due to some issues on their end - should have been about 3 weeks).

5. I removed plugs and spun by hand, then progressed to spinning with the starter motor. I remeasured the end play with a dial indicator and it's less than 0.2mm. There was some scoring on the crankshaft mating surface, but not too deep and it should bed into the bearing surface over time.

6. Buttoned it all up, added oil and started up no problem. Remeasured end play and no change. First drive went fine and no odd sounds unlike before.

Conclusions and notes on this endeavor...

It's a pretty crude approach and not for the faint of heart. Considering that I was looking at 50% of the value of the car to properly "fix", it was worth it to me to give it a shot - I have other cars to drive, so time wasn't an issue.

Also, if I had kept driving it like it was, this fix would not be possible as the wear on the crank, block, and cap would have been too great to accept a new bearing. I consider it borderline already, and had I known about this thrust bearing issue and diagnosing it earlier, the fix would be much better. The seemingly unrelated weird clutch not returning up was the symptom that really indicated the issue. And eventually a whining noise when depressing the clutch.

The bearing is 2mm thick when new - my worn bearing (clutch side) was wafer thin.

And, finally a nice fall shot:



Good luck out there and feel free to take what you will from my experience.
Thank you for doing this, the fact you literally had nothing to lose but a few hundred bucks and everything to gain by a DIY install, is truely a service to the rest of us. Very interested in long term results, I'd imagine the missing mid pan section should have minimal consequences. (Someone chime in if they disagree)

I'm VERY interested in this bit specifically:
5. I removed plugs and spun by hand, then progressed to spinning with the starter motor. I remeasured the end play with a dial indicator and it's less than 0.2mm. There was some scoring on the crankshaft mating surface, but not too deep and it should bed into the bearing surface over time.
According to VW the axial wear limit is 0.07-0.23, so you're in spec at 0.2mm with your new thrust bearing in place.
image011.png

How specifically did you measure using a dial indicator? I've thought that using a dial indicator on the harmonic damper would allow measurement of the thrust bearing:
  1. Clean harmonic damper
  2. With the clutch depressed, tap on the harmonic damper with a rubber mallet and zero the dial.
  3. Release the clutch
  4. Make note of measurement
Is this how you got a measurement of 0.2mm by chance? This could very well be a way for other GTI owners to measure their own thrust bearing wear over time and possibly catch impending doom before it happens. But the accuracy of this method (Or another method) of measurement needs to be verified, and your situation might be perfect for this purpose.

I've thought of doing this myself when I get a hold on a dial indicator, but right now I feel the measurement is kinda meaningless without a baseline measurement.
 

ArrgRer

Passed Driver's Ed
Location
USA
Car(s)
Mk7 VW Golf R
I wonder in their "secret" is cutting the mid pan like you did?!


Thank you for doing this, the fact you literally had nothing to lose but a few hundred bucks and everything to gain by a DIY install, is truely a service to the rest of us. Very interested in long term results, I'd imagine the missing mid pan section should have minimal consequences. (Someone chime in if they disagree)

I'm VERY interested in this bit specifically:

According to VW the axial wear limit is 0.07-0.23, so you're in spec at 0.2mm with your new thrust bearing in place.
View attachment 264302
How specifically did you measure using a dial indicator? I've thought that using a dial indicator on the harmonic damper would allow measurement of the thrust bearing:
  1. Clean harmonic damper
  2. With the clutch depressed, tap on the harmonic damper with a rubber mallet and zero the dial.
  3. Release the clutch
  4. Make note of measurement
Is this how you got a measurement of 0.2mm by chance? This could very well be a way for other GTI owners to measure their own thrust bearing wear over time and possibly catch impending doom before it happens. But the accuracy of this method (Or another method) of measurement needs to be verified, and your situation might be perfect for this purpose.

I've thought of doing this myself when I get a hold on a dial indicator, but right now I feel the measurement is kinda meaningless without a baseline measurement.

There cannot be another way without cutting the mid-pan - they may go a step further and tig weld or braze it back in once done. I don't see that mid pan section providing any significant structural value and I'm not worried about it.

Regarding the dial indicator - I have a mount with a strong magnetic base that I just put on the frame rail and arrange the arms so that the plunger is perpendicular to the harmonic damper. Here's a pic with no bearings installed:

1667244659829.png


The pan was off so I just used a large screwdriver to move the crank all the way in (toward the clutch), zero the indicator, and then move it all the way out. I did the same process after installing bearings and spin test but I didn't get a pic. Super easy with the pan off since you can just pry against a journal and a crank counter weight.

I did try to replicate it after putting the pan on, oil in, and run the engine test and it was certainly more difficult to get a good measurement compared to the pan off. Like the guide mentions, I struck it with a large rubber mallet to attempt to move it all the way in, then setup my dial indicator, zeroed it, and used a large screwdriver behind the balancer to pry it out. I didn't have a helper to push the clutch in which may have been a better method. It worked, but wasn't great as I was afraid of prying against the timing chain cover - I'll look for a better pry point next time or get a helper. Either way, you pretty much have to remove the fender liner and washer fluid reservoir to have good access to do the measurement.

I honestly think that it's easier and more accurate to just drop the pan at one of the oil changes to take the measurement. And, yes - getting a baseline for whatever method chosen is most important.

I'll be sure to update here after a week of real driving and at period intervals.

Good luck.
 
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