6MT clutch spring rattle sound

[Rajmun340]

Originally Posted by deansbimmer

I’m not here to force knowledge on anyone if they don’t want it. Look up the PN for the clutch. Find pics of the actual part, not a generic realoem clutch image. Im speaking from real first hand experience from working on these M3’s daily, not from google.

Your theory that this noise is driveshaft related is proved wrong from simple observation and I don't mean to diregard your hands on experience which i was vaguely aware of. The noise could not be there when shutting off the engine with gearbox in neutral. But it is. Period.

PN numbers mean nothing. You can find 21212284034 at ECS advertised as the original equipment components without hub springs but it is not the factory clutch. Turnermotorsport sells the same PN kit made by Schaeffler (INA, LuK, & I NA) who also made the original clutch but they've modified it along the way. The getBMWoem picture is no generic picture it is the actual factory clutch. You're going to tell me that you've replaced clutches with this kit, i know but the original clutch and the dual mass flywheel are permanently connected and have to be replaced as a set. Where is your questionable knowledge now ?

[deansbimmer]

I don’t hink youve read my posts to fully understand my position on the source of noise.

There are a few on this forum who are just combative by nature and have been added to my ignore list. You’ve proved that you too belong on that list. If you want to pull your clutch to find that Bmw didn’t use spring hub clutches in these cars, feel free. I’ve been changing them since these cars came out. I don’t have to prove anything here. I came in to help save you time and put your mind at ease but it seems that you have more than enough understanding of the car to diagnose and resolve the the issue yourself. I’m out...

[R3dliner]

If I don't give enough gas at a stop I hear kind of a marbles in tin can noise but I would suspect that's normal. This trans is mighty noisy though. Chatter is unreal sometimes.

[Rajmun340]

Originally Posted by deansbimmer

I don’t hink youve read my posts to fully understand my position on the source of noise.

There are a few on this forum who are just combative by nature and have been added to my ignore list. You’ve proved that you too belong on that list. If you want to pull your clutch to find that Bmw didn’t use spring hub clutches in these cars, feel free. I’ve been changing them since these cars came out. I don’t have to prove anything here. I came in to help save you time and put your mind at ease but it seems that you have more than enough understanding of the car to diagnose and resolve the the issue yourself. I’m out...

Look, you've been proven flatly wrong about your driveshaft theory in this case and that is from confirmed technical observation when shutting off the engine in neutral. There is nothing personal in it on my side. Your integrity is poor for trying to change the subject and starting to throw personal attack is quite despicable.
The existence of hub springs is not changing any of that. If you didn't throw your supposed knowledge as condescendingly as you did maybe you would not feel butt hurt when proven wrong. Just think about that.

[R3dliner]

Originally Posted by Rajmun340

Look, you've been proven flatly wrong about your driveshaft theory in this case and that is from confirmed technical observation when shutting off the engine in neutral. There is nothing personal in it on my side. Your integrity is poor for trying to change the subject and starting to throw personal attack is quite despicable.
The existence of hub springs is not changing any of that. If you didn't throw your supposed knowledge as condescendingly as you did maybe you would not feel butt hurt when proven wrong. Just think about that.

Raj you sound like a tool lol. I think your the less credible person here. How many engines have you built or swapped?

[Rajmun340]

Originally Posted by R3dliner

Raj you sound like a tool lol. I think your the less credible person here. How many engines have you built or swapped?

It's not about he says, I say it's about the facts. When you're proven wrong you owe to it and that is a sign of professionalism or lack of. No matter your credential.

[doogee]

deansbimmer is correct. OP your "99% sure" theory is wrong.

Neither of the two clutches have springs. They never did. Ever. Period.

I listened to the sound clip and this noise is not coming from your clutch. Sounds just like the driveline unloading. There is usually always going to be some load, even in neutral. Want to try a cool experiment? Put your car in the air and leave it in neutral. Your rear wheels are going to be turning. Mind blown?


If you want something smooth and quiet, the M3 isn't for you

Also your rude and condescending attitude doesn't really earn you any help or factual information.

So I hope this problem drives you insane. You'll never get help.

Originally Posted by Rajmun340

I say it's about the facts. When you're proven wrong you owe to it and that is a sign of professionalism or lack of.

You're going to have to admit you're wrong

[Scharbag]

Originally Posted by deansbimmer

Sounds like driveshaft and differential backlash, not clutch related. Very common.

But there were a few things in here that I can clarify.

First- In neutral the transmission main shaft is still rotating with the engine. You can still hear chatter in the transmission, and the driveshaft can still be motivated back enough to make a slight backlash sound upon shutdown. Pushing the clutch in disengages the transmission input shaft so if you want to try that test again, try it with the clutch in.

Second- I posted a thread where a clutch failure led to a fire. That was from broken spring straps. Those would make a much different sound than what the video dictated (think marbles in a can).

The E9x M3 6MT is loud and clattery. Most manual transmissions are clattery due to gear lash and the way it gets fixed is by using a heavy arsed flywheel. If you ever go to a race track and listen to the cacophony of wonderful sounds that spew forth from a proper race car, you will appreciate how quiet the M3 is for the level of performance that it has.

:P

[gingerbread]

This is the factory clutch, no springs in the clutch disc's (two friction disc in this clutch) The sprung hub is not needed with a dual mass flywheel, as it has the springs with in the flywheel controlling the two parts of the flywheel.

The pressure plate has a friction disc with a large female spline then a double sided steel disc as one unit. The second friction disc has a smaller male spline that fits the first friction disc splines and also has the splines for the input shaft from the trans. You can see the all this better in the second photo... same clutch just with different friction material on the disc.

I have to correct you on what you said here "i know but the original clutch and the dual mass flywheel are permanently connected and have to be replaced as a set. Where is your questionable knowledge now ?" The clutch and flywheel are bolted together with 6 bolts. Only the pressure plate, first disc and double side steel disc are "permanently connected". BMW did update the flywheel and complete clutch assumably around 09/2008, so ya if you had an older build car you need replace everything. But no they are not "permanently connected".

Also as I posted earlier to you "sounds like some chatter from the twin disc clutch or gear lash in the trans." The splined connection between the two friction disc's does have some free play, it's needed to help the two disc move and disengage properly.

...On the gear lash statement "It cannot be gear lash. When I put the gear in neutral and then turn off the engine, i can hear the same rattle just as the engine stops rotating." Just because you are in neutral doesn't mean the gears aren't spinning. The input shaft, the counter shaft and gears will always be spinning with the engine running and clutch engaged.

Here's a informative video to check out.

55 seconds to 1:30 min mark check it out


Here are my 3 suggestions for the noise. 1. Twin disc spline noise. 2. Trans gear lash/chatter 3. dual mass flywheel wearing out, has to much angular rotational play

[Rajmun340]

Originally Posted by gingerbread

Here are my 3 suggestions for the noise. 1. Twin disc spline noise. 2. Trans gear lash/chatter 3. dual mass flywheel wearing out, has to much angular rotational play

The M3 is not my current stable favourite and I started to forget about this. But back into it with a fresh mind.
The thread started to veer off in a mis-diagnosis when DB thought justified on imposing his theory of the driveshaft and rear differential jerking the trans through fluid friction load in neutral. But I knew from the start that the live noise is unmistakenly driven by real compression spring(s) releasing stored energy and made this clear at post #15. DB persisted (wrongly so) in "the driveline's stored energy behaving like a spring in this context" #16.

When it comes to the location of the springs I recognize i was mislead by the bmw parts diagram that placed compression springs in the clutch disk. I don't know why i forgot about the dual mass flywheel arc compression springs (thanks to Gingerbread for bringing my attention on it ). it's them off course that are driving this noise (real springs indeed). So i asked myself how can a DMF fail ? Here is what i found from ZF (Sachs) fault diagnosis for a noisy DMF :

"if the primary flywheel can be rotated in the opposite direction from the secondary flywheel of a Sachs DMF by hand (tilt) more than 20 millimeter, it’s possible the inner torsion damper springs have fractured. this is best assessed by comparison with a new unit, which typically has only 2 millimeter tilt". They also say the DMF torsion damper springs are a wearing component which I think is unnaceptable given it's not a scheduled maintenance part for the car. I know my car was never launched or abused by me since factory, unless it was by a stealer mechanic (which is not impossible unfortunately).
Given how little experience dealer mechanics have on DMF (almost all the cars they see are single mass flywheel) i was not surprised my dealer could not diagnose it. Despite all the diagnosis tools they have they typically don't admit anything is wrong until something is broken and some system fails to operate or throws a code.

This video shows how the DMF oscillates except our DMF probably has several individual springs like this one below not just two. (watch around 2:10)

Here is the ZF DMF fault diagnosis article. Scroll down past the DCT paragraph :

https://autotechnician.co.uk/zf-dual-clutch/

another related article :

http://pmmonline.co.uk/technical/dmf...iagnosis-tips/

This all fits into my original suspicion of an underdamped oscillation from worn or broken springs.

btw since this is a dmf issue, it can affect dct M3's too which have a slightly lighter duty rated dmf than 6MT.

[rcracin]

Rajmun, I guess you're still posting because it's your thread. But hopefully anyone that comes across it understands that deansbimmer should be believed over you 100% of the time.

[Rajmun340]

Originally Posted by rcracin

Rajmun, I guess you're still posting because it's your thread. But hopefully anyone that comes across it understands that deansbimmer should be believed over you 100% of the time.

I have proven my point already, It's the DMF springs, not the driveshaft and rear differential.

[rcracin]

Yea sure, we’ll believe the guy who google researches over the guy who has every part you’re talking about lying around in his garage and knows how they work.

[Rajmun340]

Originally Posted by rcracin

Yea sure, we’ll believe the guy who google researches over the guy who has every part you’re talking about lying around in his garage and knows how they work.

indy BMW specialized shop mechanic friend with 15 years of experience drove my car this morning and he said worn DMF and gearbox input shaft and associated bearings.

[Bartledoo]

Originally Posted by Rajmun340

indy BMW specialized shop mechanic friend with 15 years of experience drove my car this morning and he said worn DMF and gearbox input shaft and associated bearings.

Then disassemble and verify. Case closed.

[kimiraikkonen]

Originally Posted by rcracin

Rajmun, I guess you're still posting because it's your thread. But hopefully anyone that comes across it understands that deansbimmer should be believed over you 100% of the time.

This thread very quickly became a shi*h*le thread when Rajmun340 was insistent on clutch hub springs (based on a generic RealOEM diagram).....while at the same time trying to debate Deansbimmer (who has always shown to be quite knowledgeable and a great M3post member in sharing his knowledge).

Rajmun340 should just admit he was mistaken and move on. Trying to push a dead-horse cart up the hill is not counterproductive for anyone.

[pbonsalb]

Originally Posted by Rajmun340

Given how little experience dealer mechanics have on DMF (almost all the cars they see are single mass flywheel) i was not surprised my dealer could not diagnose it. Despite all the diagnosis tools they have they typically don't admit anything is wrong until something is broken and some system fails to operate or throws a code.

BMW started using dual mass flywheels 25 years ago. Dealerships are familiar with them. But I think you prefer to diagnose things yourself rather than seek the help of professionals like deansbimmer or a dealer or independent. If a person has some real world mechanical experience, the internet can be a helpful aid, but based on what I have read here, it appears you do not fall into that category.

[Rajmun340]

Originally Posted by pbonsalb

BMW started using dual mass flywheels 25 years ago. Dealerships are familiar with them. But I think you prefer to diagnose things yourself rather than seek the help of professionals like deansbimmer or a dealer or independent. If a person has some real world mechanical experience, the internet can be a helpful aid, but based on what I have read here, it appears you do not fall into that category.

For those who are posting without having read the evolution of this thread : Deansbimmer was absolutely wrong from A to Z. Period.
I was only wrong about assuming the dampers were in the clutch when they are in the DMF. The issue has absolutely nothing to do with the driveshaft and rear diff. Nothing. I was right about that. My car's noise has now been diagnosed by no less than three independent BMW specialized dealers. The first mechanic has 40 years of experience on BMW, Mercedes, Porsche, second one worked 20 years at a BMW dealership until starting his own shop couple years ago, owns a E92 M3 manual. Third one works in specialized BMW shop. ALL have diagnosed a bad clutch and/or DMF. Not only that but i have found other M3 owners who have had the same exact issue and already had a new clutch + DMF eliminating the noise. My car will be taken apart.

Deansbimmer was absolutely wrong. Period.

[pbonsalb]

Probably taking everything apart and putting it back together with new parts and changing the fluid will reduce the drivetrain noise for a while.

[Scharbag]

Originally Posted by Rajmun340

Your theory that this noise is driveshaft related is proved wrong from simple observation and I don't mean to diregard your hands on experience which i was vaguely aware of. The noise could not be there when shutting off the engine with gearbox in neutral. But it is. Period.

You are very quick to flatly state that others are wrong doode. It is typically considered as rude to ask for advice and then dismiss said advice when you have a different opinion on the matter. And it is usually a good thing to know what you are talking about before stating "facts."

Shutting off an engine with the clutch engaged (foot OFF clutch) will typically result in some of the worst gear lash noise due to rotating inertia in the gearbox coming to a halt due to compression stopping the engine. My old VW with an O2M transmission and light single mass flywheel sounded like an angry man with a large hammer wanted out of the gear case every time you shut off the engine. This was due to really coarse (stronger by far than the O2J) gear sets. Nothing you could do about it except use the heavy factory dual mass flywheel. Now, if your dual mass damping assembly is pooched, it may make additional noise, but to say that there will be ZERO noise emitted from a 6MT gearbox when in neutral is not accurate.

If you think you are right, then change your clutch and report back. I would be very surprised if your M3 6MT was silent afterwords cause they are clattery pigs from the factory.

Cheers,

[Bartledoo]

Originally Posted by Rajmun340

For those who are posting without having read the evolution of this thread : Deansbimmer was absolutely wrong from A to Z. Period.
I was only wrong about assuming the dampers were in the clutch when they are in the DMF. The issue has absolutely nothing to do with the driveshaft and rear diff. Nothing. I was right about that. My car's noise has now been diagnosed by no less than three independent BMW specialized dealers. The first mechanic has 40 years of experience on BMW, Mercedes, Porsche, second one worked 20 years at a BMW dealership until starting his own shop couple years ago, owns a E92 M3 manual. Third one works in specialized BMW shop. ALL have diagnosed a bad clutch and/or DMF. Not only that but i have found other M3 owners who have had the same exact issue and already had a new clutch + DMF eliminating the noise. My car will be taken apart.

Deansbimmer was absolutely wrong. Period.

Don't count your chickens before they hatch...

[8500RPM]

I have that same noise in my 2012. Happens mostly when I'm clutching going reverse