Weeeird Clutch Issue -- RPMs go UP when clutch pedal in

[9kracing]

I actually have no idea, but I'm following closely, I'm very curious.

I thought maybe I had an idea until you said the RPMs keep going up. I'm wondering how high they will go if you just let it go.

[ATB88]

I actually have no idea, but I'm following closely, I'm very curious.

I thought maybe I had an idea until you said the RPMs keep going up. I'm wondering how high they will go if you just let it go.

Yeah I was curious too, but not curious enough to hold the clutch in that long. The mechanical feedback and sound were enough to convince me that I'm tempting fate every time I do this lol.

In any case, it does seem like there's a problem in the bellhousing that's probably independent to what was making the revs go up, based on my last drive.

[ATB88]

Just wanted to update and clarify what's going on with this issue! I've been able to reproduce it on shorter drives, not completely reliably, but I can often get it to happen when I'm shifting from in higher RPMS (~4.5k+).

-Sometimes when I shift in these conditions, when the clutch pedal gets to the bottom of its travel I will feel some mechanical rumbling/feedback through the clutch pedal and hear a loud and RPM dependent whine as the revs change. It sounds and feels bad. Based on the feeling in the clutch pedal and the noise, it would seem that there's absolutely something weird/bad happening in the bellhousing.

-When the above happens, sometimes but not all the time, revs will go *up* instead of down when the clutch is fully disengaged (foot at bottom of clutch pedal travel). Since it doesn't always happen, I'll assume at this point that this is a separate issue from the above that just happens to coincide with it sometimes.

I'd first like to focus on the problem in the bellhousing. I realize that if there's something wrong in there (bad throwout bearing, pressure plate, etc) it doesn't really matter what it is the treatment is the same -- I'm dropping the transmission and doing a full clutch job and refresh in there. That said, I would really like to figure out what exactly went wrong here or if I made some error on install last time I was in there. The clutch, throwout bearing, slave cyl, really every part inside the bellhousing aside from flywheel, has 50k miles on them, so whatever this failure is it seems premature.

Any thoughts ideas?

[ATB88]

Bump! Really hoping to figure out what's going on with my clutch. I probably don't have time to drop the bellhousing until December, so I'm hoping to understand what's happening in there and see if I can mitigate further damage by driving carefully until I can repair. Thanks for any ideas!!

The main problem I'm trying to figure out: when I put the clutch pedal in at higher RPMs (4.5k+), when the clutch pedal hits the bottom of its travel I often get strong mechanical feedback through the pedal and a loud rpm-dependent whine, which lets up when I raise the pedal again. This doesn't *always* happen when I shift at higher RPM. I can avoid it by shifting at lower RPM or not completely taking the clutch pedal down to the clutch stop when I shift at higher RPM. It feels/sounds like something in the bellhousing is touching something spinning that it shouldn't be.

Clutch and all associated hardware have 50k trouble free miles on them, all installed when I performed 6MT swap 5 years ago. Used LuK clutch kit, OE BMW throwout bearing, slave cyl and clutch fork, aftermarket upgraded bronze clutch fork pivot pin. Original flywheel (96k miles).