6MT Gearbox Rattle?

[jmciver]

Has anyone with a 6MT ever notice a gearbox rattle after the car (and transmission) has reached normal operating temperature? A few weeks ago, I stopped in a paring lot to check something on my phone and my radio was off. I was not looking for any type of rattles, but some rattling from the transmission caught my attention as I had never noticed it before. When I push the clutch in, the rattling goes away.

Now I am familiar with this type of transmission rattle - my E46 M3 track car has it. But my E46 also has an aftermarket lightweight flywheel and high performance clutch (replacing the stock dual mass flywheel) so gearbox rattle at idle is expected. My understanding is that the F8X does have a dual mass flywheel in stock trim.

I am not too worried from a damage perspective (at least not yet ) as gearbox rattle is not typically anything to worry about under most situations. However, I was wondering if anybody else has experienced this before. My car has almost 30k miles on the clock and I plan to change out the transmission oil as part of my scheduled preventative maintenance plan. Also, I noticed that the rattle only occurs at idle after the transmission is up to normal operating temperature. This would lead me to believe that maybe a slightly thicker transmission oil may help.

Thoughts?

[MrSmartyPants]

I have the same thing on my 2016. IMO, normal gear rattle. Fairly faint, not too loud. Only when warm (trans fluid is thinner) and at idle do I notice it.

[Ravcik]

You had noticed this rattle when transmission is on idle ? - if yes go to dealership and check this.
I have similiar situation. When car warm up and i was drove on parking useing only 1 and 2 gear, smth rattle when i release clutch pedal.
Finnaly Dealership dont know what to do with this and they replace clutch with flywheel, it didn't help.
They told me that M3 in overal is very "mechanical" car and this noises are normal.

[jmciver]

My car will be going in for service very soon so I plan to have them look into it. But honestly, I am not expecting much as I know all gear boxes will rattle a bit - a trade off between performance and luxury (i.e. keeping NVH down). And the gearbox rattle is not overwhelming IMHO. But I will wait and see what they say...

[ntg44]

Just to be clear, are you referring to clutch/flywheel chatter? Or are you feeling something through the shifter?

Mine chatters sometimes, but it doesn't bother me because my old 350z chattered much louder. Car is fine.

There's an older thread on chatter, if it's what you're referring to:

https://f80.bimmerpost.com/forums/sh....php?t=1359595

[jmciver]

I am referring to what I think is clutch/flywheel chatter. At least that is what it sounds like to me based on my experience with my track car that I described above. I don't think it is that big of a deal. But I was surprised that I noticed it "all of a sudden" after two years of ownership.

I am usually not too sensitive to "weird" sounds coming from the car. But I was just a bit surprised that I noticed this sound, and I was not looking for it. Also, when my E46 M3 was stock, with the dual mass flywheel, I never heard any gearbox chatter until I upgraded the car with the racing stuff....