Gear noise, DMF chatter?

[jayware33]

Hi,

I recently picked up a 2008 3.0si coupe manual but worried about a noise I’m hearing and getting a little worked up over it. I seen a previous thread detailing something similar but the videos are no longer available to compare. I’d really appreciate if people from here could watch mine (sound more noticeable later in the video) and see if this is the classic gear rollover/input shaft noise that I believe was described as a characteristic?

My last 3.0si I think made this noise but can’t remember. It also chatters slightly on uptake when pulling off. Noise only happens when warm and when in neutral with foot off clutch. If I press the gearstick forward slightly (but don’t engage a gear, the noise goes away too. Other than that, the car drives and pulls without issue, no slipping etc. car is on 59k miles and full BMW history. Original gearbox oil too so will dump this out replace with 75-90 LT3 …. (I think that’s the correct oil for this)??

https://youtube.com/shorts/SVYJkglUPCI?feature=shared

Thank you.

 

[smorris_12]

I would say it's the release bearing rattling on the input shaft. With the clutch pressed it's sandwiched between the pressure plate and the clutch fork so can't move. Possibly there's slightly too much clearance on the shaft or it's too short so there's no pre-load between plate and fork.

Oil change won't help (but does no harm.) Don't suppose there's an easy answer.

 

[jayware33]

Thanks for the reply.

Booked my car into a gearbox specialist for a health check. He thinks it’s related to the clutch springs and usual chatter from these drivetrain setups. He given me a few things to try to rule out trans issues which seem to check out which make me feel better. The car runs absolutely fine so tempted to just live with the nature of it for now.

He said to apply some gentle accelerator Im while in neutral and foot off clutch, this will create some centrifugal force and stop any loose components clanking around (like spring in the clutch assembly) … when I done this, the noise goes away so he essentially said this eliminates the trans from generating that issue I report. Will get a full health check though - he said these boxes are generally very reliable if looked after.

He also mentioned that in most cars (especially BMW) when setting off in a gear, there is usually an audible chatter (I heard it in my previous Z and M140i). This is caused by the gear uptake in the transmission due to small tolerances and sound being transmitted through to the cabin. The input shaft can also rattle around and generate noise but all to be considered normal variances and each car will be slightly different, some louder than others.

 

[Ed Doe]

My old 3.0si was similarly rattly - it's not gears it's flywheel chatter for sure. Wouldn't be overly worried myself!