Clutch and flywheel replacement - let's talk

[CamasM3e93]

My 6MT e90 has 149k miles, presently NA but drove 100k supercharged miles on a couple different platforms (Harrop and ESS 550). The car has seen at least 30 track days and may see more but at a more casual pace (like a few days a year instead of 3 days over a long weekend - I tracked it heavily in 2024).

Somehow the clutch is still going strong but I've developed some flywheel chatter over the last few months so figure it is time to plan for transmission out and a clutch/flywheel replacement. The car is going to spend the rest of its life NA. On the drive shaft, the Guibo has been replaced but nothing else on the drive shaft has been addressed (to my knowledge)

I plan to do a stock clutch since they are so robust and reliable. For purposes of discussion:

--Can anyone speak from their experience to the daily drivability of a lightweight flywheel option coupled to the stock clutch? Which one did you have? Any bad experiences you regret?

--Is the slave cylinder a must do? My other car has a problematic slave cylinder design and so it's a must do 'while you are in there' on a clutch job. Haven't heard anyone ever complaint about this car's slave cylinder so if I can just re-use it I suppose I will.

--I am planning a rear end rebuild on the car probably in 2026. CSB on the driveshaft now or let is wait until 2026?

--What else do I need to think about for the work?

Cheers, all.

[m3s65b4.x]

I'm also interested about lighter flywheel and maybe stronger clutch which gives harder pedal feeling like e34 3,6 m5.
And have to replace slave cylinder. 2 yrs ago replaced brake fluid and bleeded several times but still has bad 2nd gear engagement from 1st mostly in winter time. To avoid that syncro grinding better start to drive with 2nd gear. when oil is warmed up then no problem.

[AYSchweiz]

I can't speak on stock clutch with lightweight flywheel, but my car had a SPEC single mass flywheel and clutch in it when I got it. I was not a fan of the single mass flywheel. There was too much added NVH for my taste, and when I had stiffer transmission mounts in the "can of marbles" sound was pretty unbearable just driving around town. I swapped back to the stock clutch and DMFW and couldn't be happier.

As far as the slave cylinder, it's an $85 part and adds ~10 minutes to the job, I think it's worthwhile to just change it out and not worry about it down the road.

[RocketyMan]

When I took off a manual trans last, I did the clutch release bearing. It def helped with perceived noise in the cab as the original one seemed to dry out just after 80k miles.

I also did the pivot pin in the trans to the upgraded "bronze" one. I had to enlarge the hole a little bit in the trans bell-housing. But it fit fine after that. Not sure this is much of an issue other than a solution looking for a problem -- so to speak.

Another thing to add is the shifting shaft seal that sits at the top. I guess these have been known to leak.
https://realoem.com/bmw/enUS/showpar...diagId=23_0966
https://www.fcpeuro.com/products/bmw...ng-23121282394


If you go away from the DMF to a single, I think you'll lose alot of that "luxury" feel and get more perceived NVH. Somewhere on the forum I read that someone who went to a lightweight flywheel ended up needing a new clutch after a year because it somehow translated to wearing the friction disc more on the clutch.

[AYSchweiz]

Originally Posted by RocketyMan

When I took off a manual trans last, I did the clutch release bearing. It def helped with perceived noise in the cab as the original one seemed to dry out just after 80k miles.

I also did the pivot pin in the trans to the upgraded "bronze" one. I had to enlarge the hole a little bit in the trans bell-housing. But it fit fine after that. Not sure this is much of an issue other than a solution looking for a problem -- so to speak.

Another thing to add is the shifting shaft seal that sits at the top. I guess these have been known to leak.
https://realoem.com/bmw/enUS/showpar...diagId=23_0966
https://www.fcpeuro.com/products/bmw...ng-23121282394


If you go away from the DMF to a single, I think you'll lose alot of that "luxury" feel and get more perceived NVH. Somewhere on the forum I read that someone who went to a lightweight flywheel ended up needing a new clutch after a year because it somehow translated to wearing the friction disc more on the clutch.

+1 On this. IIRC the LUK clutch kit actually includes a new throw-out bearing, but you might also get a new guide tube if yours looks beat up, and input shaft seal is easy enough to replace while you're in there.

FYI, when I got all the parts the best price on a LUK clutch kit and DMFW was actually on RockAuto (I think almost 1/2 FCPEuro cost).

[RocketyMan]

Originally Posted by AYSchweiz

+1 On this. IIRC the LUK clutch kit actually includes a new throw-out bearing, but you might also get a new guide tube if yours looks beat up, and input shaft seal is easy enough to replace while you're in there.

FYI, when I got all the parts the best price on a LUK clutch kit and DMFW was actually on RockAuto (I think almost 1/2 FCPEuro cost).

Yup! Rockauto is the place where to get the clutch and flywheel. LuK is the OE supplier for this commodity.

[RugbyBro]

Do everything - clutch, flywheel, slave, bearings, guide tube, fork, pivot pin, etc. By your account this is a once every 150k job so you should just get it all done at once.

I'd love a more stiff feeling clutch pedal like my E46 (stage 1 clutch) but that really comes down to the hydraulic assist (which you can't really change) and the pressure plate. The stock E92 clutch action is just way too light IMO... but I'll admit it does make it a very easy car to daily.

[CamasM3e93]

Great intel and feedback from everyone. I will stick with the stock flywheel and clutch. I got a chuckle out of my pondering over the slave cylinder. My last slave cylinder on a 996 was $1300 just for the part, here they range $60-80. Rockauto was a good suggestion, too. 30-40% savings on the major pieces. My shop did my shifter shaft seal a couple years ago but for $3 i will refresh it as well. Time to take the plunge.

[amrazM]

Lightweight flywheel the ttw one specifically drives like sh*t at low speed low rpm situations, its great when the revs are up and you're driving spirited. I would stay stock and replace everything including the sliding shaft tube on the input shaft. Replacing the slave cylinder is a no brainer, the master cylinder I would suggest as well. Considering the mileage and age, the stock m/c may crap out when trying to bleed a new slave cylinder.

[CamasM3e93]

Originally Posted by amrazM

. I would stay stock and replace everything including the sliding shaft tube on the input shaft.

Thanks! I purchased all my parts this morning, including a new master and slave cylinder. I added on the sliding shaft tube at your suggestion.