Clutch Stickiness ONLY after medium-hard right turns.

[OllieVRS]

Hi all, been spewing out posts on here recently but there just seems to be so much going on with the car right now.

One of those things is the clutch pedal stickiness, most noticeable after accelerating harshly in 3rd and shifting up to 4th. Sticks for ~0.3 seconds, doesn't affect driving as it's already in gear when this happens, but sours the driving experience.

As the title says, put in a single shim 1000km ago and the clutch pedal became absolutely perfect. Now it's back to its old ways. 

I ordered three shims expecting there to be more play than there was, but only one was required to nearly eradicate all play from the bearing.

Here's a video from when I installed the shim kit. All seemed well, right?:

To investigate this again would require getting another end cap since they get destroyed when you remove them. I want to check I've not overlooked anything before going down that route, what else could it be?

Also will taking the end cap off for a second time cause enough gearbox oil to be lost to warrant topping it up/replacing it?

Cheers

[GreigC]

I use to own an Audi S4 B5. When driving hard the clutch pedal use to go really hard for a split second then back to normal…. (At times I could hear the fluid) Sometimes the pedal would go hard with normal driving but usually spirited driving caused it nearly every time. Now after replacing everything you can name in that gearbox… I won’t bore you with what was changed but it turned out to be a hydraulic line that had a one way valve inside it that was not allowing fluid to pass at times. It was collapsing inside itself under pressure. When driving it could nearly lift me off my seat when the pedal went solid… literally went hard for half a second. Although your issue may be completely different but reminded me of my issue back in the day.

[pudding]

Yeah upgrading to a braided line would be a good move as it also removes the stupid damper aka 'clutch delay valve'.  Sometimes just running fresh fluid through the line helps as it gets pretty black and grimey at the clutch end compared to the brakes for some reason.

I always did think VW not using a taper roller bearing on the input shaft to counter the thrust loadings of helical gears forcing each other apart, but VW eh? Crazy fools.

You need a good deal more force than a finger to gauge the real play, but if it's around 0.5mm as far as you could tell, that's about right.  When I fitted my MK6 gearbox, I ended up using custom shims to remove all play completely.  Even those boxes have more end float than I'd like.

If it's not excessive end float on the gearbox input shaft, the only other thing that can cause clutch pedals to behave like that is too much crank end float.

Having said that, where you changing gear at like, 6000+rpm? These boxes are notorious for not liking high rpm shifts, so could just be that.  The braided line helps with that also.

[HughOR]

@Ollie - where did you get the shim kit? I think you are in RoI too? I've only seen them on UK sites and Brexit taxes etc...
Sorry cant help with original topic !

[OllieVRS]

@Ollie - where did you get the shim kit? I think you are in RoI too? I've only seen them on UK sites and Brexit taxes etc...
Sorry cant help with original topic !

Technically it wasn't a kit. I ordered the shims desperately and the end cap on skoda-parts.com. But call your local VW dealer for parts, they might have them. You will need to measure your gearbox end cap diameter beforehand.

The shims are always WHT 001 976.

The end cap on my gearbox was 79mm, so I got 02M 301 211 B. But there is also an 83mm end cap in case yours is that size.

[HughOR]

thank you !

[OllieVRS]

Reviving this thread.

Have found out how to replicate the issue everytime. After extended breaking, say slowing down for a roundabout from a faster road, the next gear shift after accelerating will always have the stickiness. Always.

What could that be? A symptom of a failing clutch return line?

Cheers.

[pudding]

When was the clutch last bled?  Maybe fluid is a bit old and dirty and perhaps a bit of air in it?  Does it get worse with temperature?

[OllieVRS]

When was the clutch last bled?  Maybe fluid is a bit old and dirty and perhaps a bit of air in it?  Does it get worse with temperature?

Brake fluid is new since the track day plus two of my calipers have been changed. All 4 calipers bled but not the clutch line. Could air really explain the weird behaviour?

Normally it's on a roundabout just before I get home, so always noticed it with a hot engine. Will go out and check sometime if it happens on a cold engine too.

Cheers.

[grizzlydean]

Not saying this will solve the issue, but i know someone who had the same on there audi 2.0tfsi manual and after changing the issue it was actually the duelmass flywheel which was failing.

Ive got the exact same issue except ive not had to put a shim in as was solid, ive done a braided hose and master cylinder due to it being the easiest cheaper option, but il be replacing my helix clutch with duelmass once i get the funds together and i can try remember to post my results here.

Another note ive also seen on the tfsi facebook page that some people have had issues the same and it was internal gearbox issues or even crankwalk

[OllieVRS]

Narrowed down the issue to only happening after the car is thrown into a medium-hard right turn, most often noticeable after accelerating from the third exit of a roundabout or on country roads with tight right-corners.

Issue still appeared after using engine braking to decelerate rather than using the brake, so it's nothing to do with the brakes.

And it never happens on hard left turns.

Normally the pedal stick lasts for 0.3s but the car is in-gear. The longest it's ever happened for was on a track day, on an extremely hard right turn it stuck down for about 1.5s.

I'm sure @Pudding may jump to saying it's crankfloat (uh oh) but I'm really hoping to find something else. Could it be caused by something like engine mounts? Or maybe the flywheel or the clutch itself?

Also, not sure if related, but I've noticed the clutch/gearbox is noisier in reverse. Not sure if this is related or not.

[pudding]

Well the gearbox mount is the weakest one, so if a lot of engine weight is transferring onto it during a hard right hander, that could be worth looking at next.

[OllieVRS]

Well the gearbox mount is the weakest one, so if a lot of engine weight is transferring onto it during a hard right hander, that could be worth looking at next.

Gearbox you say? I did install a shim which fixed it completely (for 1000km), so could be related to some internal travel within the gearbox?

I have two more shims, all I'd need to do would be to buy another end cap. If you have a feeling that that could solve it I'd be happy to give it a shot. Bit nervous about losing gearbox oil every time I open that end cap though 

[SpongeBob]

A guy on our local car forum had this issue on his and it turned out to be crankwalk. The thrust washers were destroyed. He had an uprated clutch though.

Not his thrust washers but they were somewhat like that.

It is his flywheel though you can see were it has been rubbing on the block.

[OllieVRS]

A guy on our local car forum had this issue on his and it turned out to be crankwalk. The thrust washers were destroyed. He had an uprated clutch though.

Not his thrust washers but they were somewhat like that.

It is his flywheel though you can see were it has been rubbing on the block.

Yikes that's a scary thought. I replaced the connecting rod bearings in-situ as a precaution two years ago after my oil pressure mishaps, but I remember I wasn't able to access the thrust bearings (without taking out the crankshaft, something I wasn't prepared to do). But I would have checked them if I could.

As for the flywheel, I assume that picture you sent @SpongeBob is the view with the sump taken off. Here's mine:





These pictures are from this May, or about a year after the issue first appeared. No visible scratches.

What should I check next that doesn't involve completely disassembling the engine?

Cheers