e39 540i 6q manual (GS6 53DZ) clutch rattle

[thinksonix]

Hello, Right now i have done swap gs6-53DZ transmission into my e39 540i and when i start engine and press the clutch pedal (to half of its way) , i can hear rattle sound from clutch. First what i though that is wrong was throw out bearing. I have replaced it, but the problem is still there. When i press the clutch pedal on the floor the rattle stops. So when the clutch pedal is on the floor or on the top, i can't hear any rattle sound. but when the pedal is on half of its way, i can hear rattle

What i have installed: guiding bearing (SKF), pressure plate (LUK), throw out bearing (SACHS), clutch fork (SACHS), friction plate (LUK).

Before this setup, i have this set: guiding bearing (SKF), pressure plate (LUK), throw out bearing (LUK), clutch fork (LUK), friction plate (LUK) and the same rattle sound.

I think, that slave clutch cylinder is bad, but it doesn't leak, but the stick what goes from the clutch cylinder is not as solid ( i can move the clutch cylinder stick about 2cm from left to right at the end of the stick).could be this the problem?

[BimmerBreaker]

The slave actuating rod will always have a little play from side to side. I don't think that is the problem. I would be looking at the flywheel possibly, or the pressure plate. Do you have the locking clip on the clutch fork installed?

[thinksonix]

The clip Is installed

[jicaino]

Rattle like what? grinding rattle or like a metal part vibrating loose?

[thinksonix]

It looks sounds like bad bearing. Look at this video https://youtube.com/shorts/tSQkDWdUdOQ

[thinksonix]

Today i take out clutch slave cylinder and the stick from the cylinder has almost 4cm movement. So my theory is:
When the clutch pedal is not pressed, there is no pressure on the clutch fork with bearing. when clutch pedal is pressed to 50% of its way, the stick from clutch cylinder pushing clutch fork woth bearing down, so the bearing doesn't sit on pressure plate correctly, so it starts to make the rattle sound. When the clutch pedal is pressed to the floor, there is higher pressure on the bearing, so the bearing is aligned with the pressure plate and stop making rattle sound. This is my theory, because there is very big movement on the stick: See the picture:

https://clip2net.com/clip/m0/2c32b-clip-93kb.jpg

[jicaino]

That looks like it could rattle your bolts loose.

[KeysCoupe]

Do you have an aftermarket single-mass flywheel or an OEM dual-mass one? The single-mass flywheels cause a lot of the noise issues you are experiencing. Just about everyone I know that has 6speed swapped their Z3M’s has this issue because they all install lighter one-piece flywheels.
If you have a dual-mass flywheel, was it replaced? They do wear out and get a lot of slop that will cause a similar rattle.
-Donny

[thinksonix]

I Have single Mass flywheel made by PMC thanks to gs6 swap there was needed Custom flywheel. And the flywheel Is Brand new. Today i Have replaced the slave clutch cylinder And still rattle sound. Before clutch cylinder i Have replaced clutch bearing (Sachs)

[KeysCoupe]

If I were a betting man, I put my money on the single-mass flywheel. I’ve seen this time and time again. Change out as many parts as you will, but the noise is from the flywheel.
-Donny

[jicaino]

Why don't you drain some of the ATF in the gearbox and replace it with some MT heavier lube? I have a 50-50 mixture in my manual car that has a very light 3.6 kilo chromoly flywheel and it balanced out the chatter while still not giving any issues with the cold shifting.

[thinksonix]

I have asked on facebook e39 drift specs group, and they wrie, that this rattle makes single mass flywheel. So probably everything is ok