sharkster

Always mate! Want it to get sorted

Spyerx

Not sure, I had the 3.6RS components in my car until middle of last year. (keep in mind my car came stock with LWFW). I also had a shudder in reverse with my original setup, which was original to the car, and had 36k miles on it (not much track). But other than that the clutch was fine, no issues. When I had the engine dropped to do all the coolant lines, I had the clutch replaced completely (ALL PARTS, everything, tob, pp, fork, disk, etc) with the 4.0 parts. More track time and this happened. Keep in mind, while I'm not fast as many drivers here, I'm much faster than I was a year ago, so equipment gets worked more.

I'm a master at rev matching so that is definitely not 100% the cause. I'm so good I have no need for SPDK.

I think there is a bad batch of throw out bearings at fault here or something causing abnormal wear. That's my feeling, based on how it wore on the guide tube. The bearing is literally wobbly, hold it by the ears and you can shake the races and rest of the bearing around. Maybe lack of grease caused it to bind which wore the bearing, that's a possibility too.

Spyerx

Any ideas what is causing this type of wear/issue???

Ur20v

Its not a bad batch of CRB's or tubes- its poor material selection resulting in galling between the metals. Google galling and read the link I posted previously.

Galling causes a step which causes multiple issues- clutch doesn't release/engage properly and CRB stays in contact with pressure plate diaphragm springs which then causes heat and ultimately CRB bearing failure.

Also the cracked pressure plate diaphragm spring fingers are caused because the CRB doesn't retract fully effecting the auto-adjustment function of the hydraulic clutch which then over extends the fingers and the crack/break. IMO

Teflon plastic CRB, nearly every other manufacture of manual and automated clutches has gone this route. Or sleave the CRB or the guide tube with Teflon or Phosphor bronze... everything else is just a quick fix... just saying

NAM VET

OK, asking for an opinion. My '07 car has now 27K miles, and just talked yest with the mechanic at the shop where my engine is out, for pipes and other "consumables." He has examined my clutch and disc, the OEM one, and says the disc has lots of wear left, the fingers and pressure plate are fine. So that is going back in. I have asked him to consider replacing the release bearing, as I have always done that on when that far in in transmission. But if my original one is fine, is there a possibility of a "new" one being of lesser quality or material than the one giving faithful service so far? So, best to leave what is not broken alone?

thanks, and all the best...

Ur20v

As nothing else is available i.e better material choices I would at least replace the release bearing and guide tube.

Its not a faulty batch.

NAM VET

Ok, thanks for the suggestion.

all the best....

sharkster

hard to pin point but not all 4.0rs clutch kits are alike. even when ordering the same part numbers from different suppliers you can sometimes get different release bearings etc... Course when you chat with sachs it starts to go into what cables, trans mounts etc... I'll try to chat to James about it and see what he thinks

Spyerx

That would be helpful. In my case cup cables, cup shifter, we've rear engine mounts, Cantrell tranny mounts.

Parts ordered are the 4.0 part numbers from the pet (latest version/revs).

I still think the release bearing failed. It's grindy, and wobbly, that caused the binding and wear on the fork and guide tube.

Ur20v

Spyerx

A failed realse bearing isn't going to cause damage to the guide tube and fork unless it seizes completely and then is a big mangle of metal.

Look at the function- the bearing contact face that spins i.e contacts the clutch pressure plate is separated by the ball bearings and out race and then the CRB guide bush (inner body of the CRB) which inturn slides on the guide tube- no spinning or wear forces and exerted other than the sliding/thrust force from the slave cylinder through the clutch fork.

Trust me its galling/ fretting/brinelling form the back and forth motion of the operating CRB.

Its poor material choices. Trust me or ask a metallurgist or some one who knows failure mechanisms... ask me how I know

Fretting refers to wear and sometimes corrosion damage at the asperities of contact surfaces. This damage is induced under load and in the presence of repeated relative surface motion, as induced for example by vibration. The ASM Handbook on Fatigue and Fracture defines fretting as: "A special wear process that occurs at the contact area between two materials under load and subject to minute relative motion by vibration or some other force."

The amplitude of the relative sliding motion is often in the order from micrometers to millimeters, but can be as low as 3 to 4 nanometers.[1]

The contact movement causes mechanical wear and material transfer at the surface, often followed by oxidation of both the metallic debris and the freshly exposed metallic surfaces. Because the oxidized debris is usually much harder than the surfaces from which it came, it often acts as an abrasive agent that increases the rate of both fretting and a mechanical wear called false brinelling.

Spyerx

I get your passion regarding this but you didn't see the parts. Only the picture I posted of the guide tube. I know how a clutch works.

The races on the tob is able to move laterally a good 1/4" in either direction. This caused the action to the fork to be off center. That groove on the guide tube is on one side. This caused all the parts to move off alignment and caused the wear on the tube.

Now we frankly do not know if the tob bearing race started to fail or if lack of lube/****ty material caused binding which caused the race to fail.

I'd be happy to install a better engineered part but as far as I'm aware there aren't any. o it is what it is. Will see how long this one lasts.

bmwtye

After you get that sorted ditch the 4.0 clutch and throw the 997 RSR clutch in there. Ask Leh about his, sounds like it's a pretty awesome clutch setup.

Spyerx

yeah would want to know about drivability... his car revs like mad.

bmwtye

Here is what he told me:

The clutch driveabity is very streetable. The downside is the wear that happens. You can reshim the clutch which is cheap. But I only got 2k miles before my first shim. And you never know where you will be when it starts slipping.

The free rwb is worth that hassle to me tho. It's amazing.

Spyerx

Hmmm... not sure I'm into a 2k mile tranny drop :-)

UPDATE: So, car shifted perfectly all weekend on track, had one minor grind, that was a brain fart moment for me, too hot into braking zone and got out of whack in heel toe... anyway, very happy with the shifting now, super smooth and precise, even in hard turns shifting during turn and accel out of turn.

BUT, there is still an issue

And, I think it is the pressure plate, despite looking perfect, something is off, here is the break down:
--Shifts fine when moving and on track
--Shifts fine around town
--BUT, come off track, park car in gear, ANY gear (I tried them all), turn car off, come back to car, clutch in, start car, cannot pull out of gear (I'm using light force, not yanking on anything..that could get expensive). Rock the car a bit with clutch, it WILL come out of gear easily
--Here's the kicker: If I get in car, put clutch in, pull out of gear, THEN start, it pulls out of gear fine and shifts fine.

Hypothesis is PP is getting warped or something when hot and very, very slightly binding to make hard to remove from gear.

So: Going to discuss with shop, pull tranny, replace with a new PP, and if it goes away, got off cheap. if not, tranny is off to Bill Rader to open it up. That will hurt a bit!!!