Rattling in neutral

[Mpopaj]

Hey I posted to bimmerforums but did not get any responses. I swapped a 6-speed from an e46 m3 into my z3 coupe. It rattles when it is in neutral with the clutch engaged (clutch pedal out) and stops rattling when the clutch is disengaged (clutch pedal in). I noticed this rattle only happens when the car warms up. I have a self centering shifter and I notice the tone of the rattle changes no matter which direction I push it. This is a link to the clutch I bought.

SACHS-MAX STAGE 1 CLUTCH KIT+ CHROMOLY FLYWHEEL for 2001-2006 BMW M3 E46 6-SPEED | eBay

Click here to see description.

www.ebay.com

Is this a problem with clutch I bought, or the throw out bearing included with it? Or is it normal clutch chatter? Or is it a problem with the input shaft bearing and if so is there a supplier for this part so it can be replaced.
I could live with the noise, I just want to make sure it’s not an underlying issue.

 

[Delk]

Interesting. I have the same gearbox in my garage to go into my car soon. What shifter did you use?

Its a single mass flywheel so it wont make any noise itself but it will transfer more engine vibration. I dont know about yours but when you convert large diesels such as the Dodge Cummins you get a good amount of rattle in the gearbox when its at idle just from the engine vibration but thats normal.

 

[Lee]

Likely to be the release bearing (throw out bearing) hard to gauge if its an issue because we don't know how much noise your getting exactly. Mine used to make a little bit of noise due to the solid flywheel conversion.

Good swap that really opens up the engine on the motorways.

 

[Mpopaj]

Interesting. I have the same gearbox in my garage to go into my car soon. What shifter did you use?

Its a single mass flywheel so it wont make any noise itself but it will transfer more engine vibration. I dont know about yours but when you convert large diesels such as the Dodge Cummins you get a good amount of rattle in the gearbox when its at idle just from the engine vibration but thats normal.

I used an smg because I found it at 1/3 of the price of what the manuals are going for. I used an RTD shifter to avoid machining the Bellhousing.

 

[Mpopaj]

I was nott really sure how to post videos so I just posted the lm to YouTube here’s the link.

Rattle 1

youtube.com

In this first video you can hear the rattle being carried throughout the rev range. When I put the clutch in it stops. When I put it in first gear and start rolling the noise starts up again.

- YouTube

Enjoy the videos and music that you love, upload original content and share it all with friends, family and the world on YouTube.

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The second video shows the me pushing the shifter side to side and the tone changing.
There was absolutely no insulation in the first vid. In the second vid I used house insulation and a dust boot but I’m not sure it did much for the sound

 

[Lee]

The second video you can really hear it, to me the sound is too prominent to be a release bearing, have you checked for any clashing of the gearbox in the tunnel how is it mounted etc, and how is the shifter mounted?

A side thought have you checked the starter motor is disengaging from the flywheel.

Also did you make enough clearance for the exhaust pipes to clear the gearbox webs ?

 

[Delk]

Sounds like you installed a diesel.

 

[Mpopaj]

The second video you can really hear it, to me the sound is too prominent to be a release bearing, have you checked for any clashing of the gearbox in the tunnel how is it mounted etc, and how is the shifter mounted?

A side thought have you checked the starter motor is disengaging from the flywheel.

Also did you make enough clearance for the exhaust pipes to clear the gearbox webs ?

No I actually didn’t check for any of those things but I just don’t see how they can cause this problem where the noise only starts when the car gets up to operating temp and it stops when I put the clutch pedal in. When the car is cold it sounds perfect.

 

[Lee]

No I actually didn’t check for any of those things but I just don’t see how they can cause this problem where the noise only starts when the car gets up to operating temp and it stops when I put the clutch pedal in. When the car is cold it sounds perfect.

From what I could hear it didnt sound like it completely stopped.

Maybe clutching at straws here, in the past I've had to remove a web on that gearbox to clear the exhausts doing this swap. If it's cold at first start metal expands with heat so could be touching shortly after.

 

[Pingu]

You will get rattle if you fit a single clutch to a gearbox that is designed to use a dual mass clutch.

I can't see your video - I just get spam short videos, but the rattle will change when you push the gearlever because you are applying pressure to the gears inside the box.

 

[t-tony]

What oil grade have you put in the gearbox?

Tony

 

[Pingu]

When the clutch pedal is up, gear selection in neutral, the drive on a SMF is...

Engine Flywheel --> Clutch Body --> Clutch Pressure Plate --> Clutch Friction Plate Outer --> Clutch Plate Springs --> Clutch Plate Inner --> Gearbox 1st Motion Shaft

On a DMF, the friction plate is often solid, but the springs are in the Clutch Assembly...

Engine Flywheel --> Clutch Body --> DMF Damper Springs --> Clutch Pressure Plate --> Clutch Friction Plate Outer --> Clutch Plate Inner --> Gearbox 1st Motion Shaft

The springs in the DMF are much more effective at absorbing rotational "bounce". A DMF is often able to twist by double the number of degrees that an SMF clutch friction plate can. This extra absorbsion makes for a softer "take-up" and also reduces noise caused by engine vibrations passing through the clutch to the gearbox.

Just like putting stiffer springs on your suspension makes the care more noisy, the same happens when you put harder springs in your clutch.

You also get the same advantages - some, including me, think the extra rattles are worth the noise

The noise will be even worse (but acceleration will be faster) if the clutch assembly's mass moment of inertia has been reduced (often called "clutch lightening")

 

[Lee]

When the clutch pedal is up, gear selection in neutral, the drive on a SMF is...

Engine Flywheel --> Clutch Body --> Clutch Pressure Plate --> Clutch Friction Plate Outer --> Clutch Plate Springs --> Clutch Plate Inner --> Gearbox 1st Motion Shaft

On a DMF, the friction plate is often solid, but the springs are in the Clutch Assembly...

Engine Flywheel --> Clutch Body --> DMF Damper Springs --> Clutch Pressure Plate --> Clutch Friction Plate Outer --> Clutch Plate Inner --> Gearbox 1st Motion Shaft

The springs in the DMF are much more effective at absorbing rotational "bounce". A DMF is often able to twist by double the number of degrees that an SMF clutch friction plate can. This extra absorbsion makes for a softer "take-up" and also reduces noise caused by engine vibrations passing through the clutch to the gearbox.

Just like putting stiffer springs on your suspension makes the care more noisy, the same happens when you put harder springs in your clutch.

You also get the same advantages - some, including me, think the extra rattles are worth the noise

The noise will be even worse (but acceleration will be faster) if the clutch assembly's mass moment of inertia has been reduced (often called "clutch lightening")

Lovely explanation of how the clutch works. Did you listen to his videos ?

 

[Pingu]

Lovely explanation of how the clutch works. Did you listen to his videos ?

His videos have been deleted. I just get spam Youtube fillers called "shorts".

 

[t-tony]

His videos sound just like a tired old DMF diesel car that's been to the moon and back.

Tony.

 

[Lee]

His videos sound just like a tired old DMF diesel car that's been to the moon and back.

Tony.

My thoughts aswell. I used to run a race solid flywheel on my Z3 with an uprated clutch. Never had noises like that. Makes me think something is amiss.

Very hard to tell noises over a phone though.

 

[Mpopaj]

Like I said I don’t mind the noise as long as something’s not broken. I was just told that the noise is caused by my performance clutch kit. They said it is not clutch chatter though, it comes from inside the gearbox. This kind of makes sense to me that it is happening inside the gearbox since it does not happen when the car is cold. It happens when the oil heats up and becomes thinner. I think I’m gonna settle with this explanation and pretend my car runs perfect.
Also I don’t know why you guys can’t view the videos. I haven’t changed anything about them.

 

[Lee]

I guess you've also got the right pilot bearing in the crank ? On the gearbox I use for the conversion I need to change this bearing.

 

[Delk]

Is rhe pilot bearing correct? I understand the E46 has the pilot bearing in the flywheel farther back when the older one is in the crank.

 

[t-tony]

Most DMF clutch systems don't utilise a spigot bearing.

Tony.