thepoi

I recently started having issues getting the car into first gear from a stop, and realized that my clutch engagement point was very near the floor. I jacked the rear of the car up and verified this--the clutch starts dragging on the flywheel with the pedal about 15mm off the pedal stop on the firewall.

I'm running a Fidanza flywheel, ACT pressure plate, and OEM clutch. I can't know for certain, but it must have been engaging at a more normal pedal height earlier in it's life (the assembly is 18months old, with about 10k miles), as I've only recently noticed the issue.

I want to eliminate the hydraulics as a possible issue--I stuffed a piece of steel stock in the clutch fork window in the trans case, so the slave cylinder is just pushing directly against the case of the transmission. This preloaded the slave cylinder about 2mm. The pedal feels solid as expected (no air in the system), and doesn't sink to the floor. If my MC was leaking, I would expect the pedal to start sinking, right?

I suppose the MC bore has some sort of score in the wall that is letting fluid bypass it only when it's moving, but that seems far-fetched.

I tried adjusting the MC plunger position, but found it near its end-of-motion already. I backed it out to it's maximum position, but only gained about 5mm at the pedal (so now it's engaging at like, 20mm off the floor).

Any ideas? Anyone running into an issue with the ACT PP? That's my current theory (or the flywheel is loosening, but I poked at it a lot from the clutch fork window and and seems rigid). I don't want to pull the trans off just to verify there's nothing wrong with the clutch/PP...

Ryuu

well, you don't want to hear it, but.. it's the best way to know what your asking everyone to GUESS at... sounds like a pp has failed.. idk... pull the transmission an see... I just did a bunch of motor/ trans stuff and looked over my used clutch, an felt it was good for more miles.. and.. it still feels tall up there where I want it to release..

if you don't know, everything's a guess it's this, could be that, have you checked your power steering fluid...

thepoi

The weird thing with the pressure plate is that I've only seen them break when a strap snaps or something, and then it just makes a racket and feels gritty. Everything feels fine, everything is moving smoothly, it just requires an absurd amount of pedal movement to disengage.

I'd like to know what the slave cylinder movement is supposed to me--anyone want to measure that for me?

I recently topped off my power steering fluid with fresh maple syrup, so I doubt that's the problem.


edit:// Another note--there seems to be a lot of free play in the slave cylinder before the throwout bearing engages the fingers. I'm currently just planning to extend the goddamn slave cylinder pushrod so that freeplay is gone. But I'm pretty sure that's a bandaid to a potentially dangerous problem. Doing it anyway though.

edit2:// never mind that won't work obviously, as I need more stroke. Thats the issue. Why the hell do I not have enough stroke.

Ryuu

which maple syrup... you do know some of those natural , like Vermont and news hamshire syrups are thin, that might be the problem.. I use a standard Log Cabin.. I know.. traditional me...




the fingers on the pp weakening.. not really read of nor seen a slave have problems.. master's leak.. guessing really doesn't help, does it...

windhund116

It's 2014. Synthetic, multi-vis Maple Syrup is the only way to go!

thepoi

OK, picture time. This is the full range of slave cylinder movement (this is with the MC push rod at it's longest to get the longest pedal stroke possible. Rubber splash cover removed for clarity.





Or, 12mm of pushrod movement.

Now the fun part--can someone with an AP2 do this measurement on their car?

Just need a 12mm wrench to remove the slave cylinder, take splash boot thing off, mount it back on the trans, and take a pic with the clutch pedal up and on the floor (just like I've done).

50$ paypalled to the first one who wants to...


edit:// re: power steering fluid--I've always used traditional syrups, I've heard that switching to a synthetic after so many miles running log cabin/aunt jemimas results in uncontrollable and embarrassing leaking.

edit2:// OK, ya there's gotta be something wrong wiht the clutch/PP. I'm leaning towards clutch spring, or clutch friction material explosion. The PP just needs to move too much to disengage the clutch.

thepoi

Ugh, nothing seems out of place. Flywheel looks fine, pressure plate looks fine, clutch looks fine, although the springs are are rattling around like a maraca. That explains the recent addition of clutch buzz to my car's usual sounds, but the thickness is perfectly within spec (8.5mm). The disc is flat, the flywheel and pressure plate surfaces are both flat, well within the warpage specification. TO and pilot bearings are great, there isn't any excessive wear in the PP fingers.

What the hell? Any ideas?

Slowcrash_101

So basically you want your clutch to start engaging later in the pedal up-stroke like a worn one? My oem clutch usually starts grabbing about an inch from fully depressed and it only has 10,000 miles on it. The original I replaced had 119,000 miles on it and it started engaging about 2 1/2 - 3 inches from fully depressed.

Ryuu

I understand... I pulled mine out with over 100k miles on it expecting to order a new clutch.. after I measured everything over and over, not even the springs rattled.. so after I bounced the idea to reuse it off a couple buddies who both said.. well.. it is within specs.. I'm running on it now.. feels fine.. I didn't change it... ( mine wasn't pulled due to clutch, it was during a motor replacement and was working.. but came under scrutiny since, well, it was out, had a lot of miles.. change it )

not " knowing " what it is your feeling, thinking.. nope.. those were what I would'a done.. jacked it up, taken it out an been puzzled too...

thepoi

Yup, well, going all back together now. Lame. At least I've verified nothing is going to catastrophically fail and cut my feet off. ¯\_(ツ)_/¯