Gearbox noise/release bearing on 135i 6mt, anything on 1M?

[Imo135]

Hi

I would like to ask the 1m drivers if they have this issue with the gearbox which according to bmw it is normal on the 135i and other m cars.

On a 135i N54 6MT, when switching off the car the gearbox rattles (intermittently), bit a a metally sound, something like a bolt in a metal bucket.

Also, intermittently when standing at a robot and no gear engaged there is another rattly sound, something like a loose bolt rattling, when I engage clutch (no gear) it goes away, this leads me to believe its the release bearing. The car has under 15000 miles and is a 2008/2009.

The dealers said its due to all their performance manual cars using a gearbox with a floating release bearing and this is the character of the gearbox and is the case with all perf cars (m cars as well). Nothing can be done about it according to them.

Does anyone know what this is and does anyone have the same problem? Is the explanation provided by BMW correct? The car is still under warranty..

[Zuzu]

Have you tried depressing the clutch pedal before turning the car off.. Works a treat.

Its just the clutch release bearing rattling.

[de85275]

Originally Posted by Imo135

Hi

... when standing at a robot ...

robot = traffic signal? Just curious, I love talking to people around the world.

[AMP]

What you are describing lines up with your dealer's explanation. These transmissions do use a floating bearing and the part of the race which makes contact with the pressure plate is loose by design. It is common for this assembly to make a rattling noise when the clutch is released and the transmission is in neutral.

If the noise is excessively loud then it can signify a problem with the bearing or the transmission, but "excessively" is nearly impossible to define in this setting. If you are skeptical then you may want to take the car to another dealer or to a qualified independent for evaluation.

[flzrider]

From your description it sounds more like your dual mass flywheel than your release bearing. When you hear the noise try pushing the clutch pedal in and then releasing it very slowly.

Your sound is probably similar to this, right?

(turn your speakers up).

[Dackelone]

Originally Posted by flzrider

From your description it sounds more like your dual mass flywheel than your release bearing.

+1. YuP! It is the dual mass flywheel that makes that rattle noise when you turn off the engine. I believe in the owners manual it says to press the clutch down - when you turn off the engine. The 1M has a lightened flywheel. Not sure IF it is dual mass or not.

And Btw... the 1M and the N55 135i's have the same trans. The N54 have a different trans than the 1M. The difference being is that the N55 manual trans has shorter throws(than stock N55 vs stock N54) but the biggest difference is smoother shifting due to low friction syncro rings.

[alphagamma]

Is there any damage done if one didn't depress the clutch before turning off the engine?

[torquedemon]

yes this is one of the first things I noticed on my car. I tried multiple times starting and turning off the engine to make sure it was a recurring issue. I also noticed that when I push the clutch while turning it off, the noise doesn't come, it only happened when you turn it off without the clutch pressed. Also I hear a similar if not the same "clanking" noise when depressing the clutch to shift out of 1st into 2nd gear....it doesn't happen in any other the other gears..does anyone else experience this?

[Dackelone]

Originally Posted by torquedemon

yes this is one of the first things I noticed on my car. I tried multiple times starting and turning off the engine to make sure it was a recurring issue. I also noticed that when I push the clutch while turning it off, the noise doesn't come, it only happened when you turn it off without the clutch pressed. Also I hear a similar if not the same "clanking" noise when depressing the clutch to shift out of 1st into 2nd gear....it doesn't happen in any other the other gears..does anyone else experience this?

^^+1. YuP, that is how it works/sounds on my car too. I don't hear anything when I shift from 1st to 2nd gear though.

I think this sound is "normal" for our cars.

[GuamX1]

My car started a misfire and when it idles it sound like something is loose inside the transmission or the clutch but when I step on the clutch the sound goes away. When I step on the accelerator to about 900 rpm it does not make that sound. Shifting is okay nothing wrong. The car has 66k miles.