what could have caused this

[Rev Engineer]

After a full day of running my s50 powered e30 pretty hard, something bad happened inside the bellhousing. I was exiting a turn and shifting into 4th when all of a sudden the car started making a loud scraping sound. At first I thought the front air dam dropped and was scraping on the ground, but the noise was really coming from inside the bellhousing and varied with engine speed. The motor still runs and the clutch still works, but it sounds terrible. There is no change in the noise when you engage the clutch. After poking around under the car, I found a 1-2" hacksaw-like cut in the bellhousing. I can't find any evidence of anything shooting through the bellhousing, but there are some metal shavings on the rubber sound damping stuff. For my clutch setup, I went with a shaved/lightened e30 325i flywheel and e30 325i clutch/pressure plate.

Anyone care to guess what might have happened? Also, any tips or tricks on getting the trans out without taking the engine out would be greatly appreciated. I can see how this might be very difficult. Can anyone confirm that it can be done? I could also use recommendations of a new flywheel/clutch setup that doesn't involve spending 1k for the m5 setup? Maybe the e30 325i setup can't handle the high rpms. The motor spent most of the day between 6400-7000 rpms.

[FredK]

Wow! I guess we'll find out what it was once you pull the transmission! Good luck with extraction. I think there are some threads that have some tips on transmission extraction with the engine still in the car.

[BigD]

I went with a shaved/lightened e30 325i flywheel and e30 325i clutch/pressure plate.

Since your clutch still works and the above piece of information, I'd bet my lunch money that your flywheel broke and a chunk of it flew off.

[Jason89i]

well, if the sound is constant (regardless of clutch in or out) and varies with engine speed.......it has to be from the pressure plate to engine. i have seen those pesky pressure plate bolts come loose if locktite was not used. it makes sence that one could have fallen out and lodged between engine and flywheel. if you used the e30 singlemass flywheel......did you shave the pan bolts or shave the flywheel? did you have a lot of clearance between the fly and pan?

i have disenegrated a few clutches. centrifugal force of high revs can literally pull the clutch material off the disc. however, the satch clutches will hold up to over 8k. ive never destroyed a satch clutch.

the only difficulty of pulling the trans out (from the bottom) is the headers and those pesky upper mounting bolts. if the car is on a lift, its not too bad. you can use 42" extension / wobble to get to the upper trans mounting torx. the trans usually gets wedged between the tunnel and the headers. if the tunnel insulation is out, removal of the trans is much easier.

sorry to hear about your troubles.......but at least you were having fun when it happened. cheers, jason

[Beej '86 325es]

Maybe your throwout bearing is trashed...
I wore the clutch on my 325es down to the rivets about 6 years back and wore it down enough that part of my throwout bearing flew off and rattled around in there, knocking off my flywheel reference pin.

[Gus]

nasty...lowering the engine on the front subframe can help get to the top bolts, havent tried this on a 24v though. and it is a PITA to get back in, but hey it works. also make sure you disconnect all things that may break from lowering engine

[gobuffs]

BMW pressure plate failure is becoming all too common of an issue in the past few years.

[Van Westervelt]

... satch clutch...

Do you mean Sachs?

[asubimmer]

BMW pressure plate failure is becoming all too common of an issue in the past few years.

yeah and all i's are 4 doors too right?

[92 mtechnic cabrio]

i have disenegrated a few clutches.

you mean disintegrated ?

[FredK]

WTF. It was clear what Jason said. He's one of the most helpful guys on the 24v forum. Stop quibbling with his spelling.

[Van Westervelt]

Could have easily been one or more of the bands on the pressure plate. Those could snap, and continue to go around and around with the crank slicing a hole in the bell housing. Especially if you only broke one or two of them. Nasty sound, still functionable, but with a bit more stress, that pressure plate will be in pieces. IF, that is the case, which it sounds like. I couldn't see a bolt slicing through the bellhousing quite like that.

Using the stock m20 clutch and pressure plate can and will break those bands easily. A few people up here have had the bands doubled up, even on the m5 setups to eliminate that weak point.

[92 mtechnic cabrio]

just teasing

[Jason89i]

you mean disintegrated ?

yes

Do you mean Sachs?

yes

and i did mean to capatolieze (he he) all my i's, i think i forgot a few colons or semi's, maybee (he he) too many .....'s, thank goodness i dont (oops forgot the ') have any run on centenses (he he) or i might just as well start speaking italian or german, but i believe the internet is more for passing on information than writing essays and keeping grammmar. If i (oooh i got a cap'tl letter in there just for you) had to keep the sentance structures along with punctuation and speling, (he he) then i would just quit this whole internet thing.

oh yea, for all those techie physics guys.....i know its not centrifugal force that caused disc failure....its actually centripital force, but most understand the concepts of centrifugal better. (dang, forgot to use the shift key again. )

It was clear what Jason said. .

as long as you understand what im trying to say.......then its all good.

Maybe your throwout bearing is trashed...
.

typically, these make noise when the fork is putting pressure on the bearing......clutch in. after hearing your experience, maybe i should put a disclaimer on that statement.

cheers, jason

[surebimmer]

A guy that i work with installed his tranny onto his motor with the motor in the car. So it can be removed without pulling the motor. You'll need and long extension and some impact universals or normal universals to get the top bolts.