[kolosy]

for those playing along at home, i'm having a shop do my 6mt swap. they're through the coding and all the work, but are now having an issue with what at first we thought was the throw out bearing, but may now be something else. the symptoms are a loud grinding noise when depressing the clutch, with what appear to be hot spots on the clutch friction disk.

we're using this clutch kit from LUK, a genuine BMW M5 throw out bearing, and a new E92 DMF. Given that it only makes the grinding noise when the clutch is depressed, and has no issues shifting, we're not looking at the trans itself (though they did put it on a stand and spun it up to 12K rpm with no issues, or play, and they replaced the fluid in it and found no shavings). The trans is a euro spec one out of an '08 M3. Any suggestions? Any common pitfalls that we may have fallen into here? Shop owner thought it was a bad TOB at first, now is wondering if the clutch kit had the wrong pressure plate in it or something else weird.

 

[flacoramos]

Don't think anyone has mixed and matched the e90 flywheel with m5 clutch.

What fork and pivot pin are you using?

 

[kolosy]

i could swear i saw a post on here about using the E90 DMF, but are you saying in that case people use the M3 clutch as well?

i'll confirm but i think it's the one off FCP Euro's kit -- BMW Bronze Clutch Fork Pivot - AGA 21511223328 and BMW Clutch Pivot Fork - Genuine BMW 21511204229

also here's the DMF BMW Dual Mass Flywheel - LuK 21212283820

 

[flacoramos]

Afaik yes, either all m3 or all m5 clutch+fw. That's not to say what you have won't work, given you also went with a brass pin which usually gives trouble. I'd go with a stock fork pin first. Problem is we're talking about dropping the trans so shop may not be happy to try one thing at a time. Up to you how you want to proceed, but yes the m3 fw & clutch do work.

If using all m3 clutch I'd also use m3 bearing and fork.

 

[specialized2010]

i could swear i saw a post on here about using the E90 DMF, but are you saying in that case people use the M3 clutch as well?

i'll confirm but i think it's the one off FCP Euro's kit -- BMW Bronze Clutch Fork Pivot - AGA 21511223328 and BMW Clutch Pivot Fork - Genuine BMW 21511204229

also here's the DMF BMW Dual Mass Flywheel - LuK 21212283820

So you are saying the M5 clutch cover bolted on the M3 DMF? My factory 6MT current setup is a LUK M3 clutch set and LUK M3 DMF.. no issues whatsoever and it def has no issues gripping. I do have some slight noise when the clutch is not pressed down but it is due to the RTD shifter which is a non-issue. Here is a photo of the two DMF's. The left one is obviously the M5. I didnt bother test fitting the M3 clutch on the M5 DMF.

 

[flacoramos]

Doing some digging it seems the bearing and fork are common for m3 and m5. So that leaves the brass pin or you cannot mix and match m3 fw with m5 clutch.

 

[BWM]

I've also used LUK clutch and DMF for E9X M3 and it works flawlesly on my 6 MT Conversion.
Also, I've used the factory clutch fork pivot and in my experience and some other people smarter than me, bronze pivot can only cause issues because of friction issues and it's more of hype than it does some good.
When I removed SMG tranny at 139K+, the factory plastic pivot was in great shape, worn but still OK.
I'm also thinking that mixing M3 and M5 components might be an issue here but I'm only guessing.

 

[kolosy]

Thanks all, gonna keep digging and will keep y’all posted.

re: fork pin, would that be an immediate grindingnoise? That’s just a pivot point, right? Should be rpm independent?

 

[flacoramos]

We're speculating if pin or clutch mismatch. But pin sets the fork angle, which in turn can contact the rotating clutch. Or somehow allow bearing under / overextension.

 

[kolosy]

Yeah it bolted up. Do you by any chance have height measurements of both?

 

[tangle]

Yeah it bolted up. Do you by any chance have height measurements of both?

What do you think the chances are they installed geitribeseite facing the engine?

 

[specialized2010]

Yeah it bolted up. Do you by any chance have height measurements of both?

No go for the M3 DMF, but I can grab the M5 DMF later.

 

[kolosy]

No go for the M3 DMF, but I can grab the M5 DMF later.

that would be awesome — he can measure the other one himself.

 

[kolosy]

What do you think the chances are they installed geitribeseite facing the engine?

wnything is possible but generally these guys are experienced with the platform and m cars in general.

 

[flacoramos]

What do you think the chances are they installed geitribeseite facing the engine?

I like this idea. Altho unlikely due to the geared hub used to connect both friction discs. Doubt there's room to install it backwards, but I haven't tried so maybe.

The whole disc and pp also comes preassembled and shouldn't be clocked to keep everything balanced.

 

[kolosy]

Fwiw, they’re using a steel pin: BMW Steel Clutch Fork Pivot - Genuine BMW 21511223281

 

[ZiMMie]

During the clutch operation, what point does it grind? At the bottom after you are able to disengaged the clutch (or shift) or before?

 

[kolosy]

During the clutch operation, what point does it grind? At the bottom after you are able to disengaged the clutch (or shift) or before?

I haven’t driven it but it sounds like it gets progressively worse with disengagement

 

[ZiMMie]

I haven’t driven it but it sounds like it gets progressively worse with disengagement

Something is wrong with assembly, check the pivot pin, throw out bearing height or the folk.

 

[ZiMMie]

I like this idea. Altho unlikely due to the geared hub used to connect both friction discs. Doubt there's room to install it backwards, but I haven't tried so maybe.

The whole disc and pp also comes preassembled and shouldn't be clocked to keep everything balanced.

How can you keep it balanced, when the clutch disks can spin independently (when depress) from the pressure plate /flywheel.