[babym2]

this used to happen to me a lot when shifting from 1st to 2nd wot at 5-6k rpms, I learned to take a extra half a second before I throw the shifter to 2nd to allow the syncros to 'catch up', still happens sometimes, to me its the biggest flaw of the car

[mrcheezle19]

I had this same issue with my 17. Shifting at high rpms after WOT created a grind or a reluctance to go into second gear. Owned several manual trans BMWs and never had this issue till the M2. I sold the car about a year ago, but always debated having the dealer look at it, but figured it would be too much of a headache for a tech to reproduce. I wonder if the M2C has the same issue as I want a manual again, but this was rather annoying.

[AlpsRider]

Originally Posted by babym2

this used to happen to me a lot when shifting from 1st to 2nd wot at 5-6k rpms, I learned to take a extra half a second before I throw the shifter to 2nd to allow the syncros to 'catch up', still happens sometimes, to me its the biggest flaw of the car

There is an art to shifting without over working the syncros. Many people have never shifted a transmission without syncros so it's easy to think that the gears should just mesh perfectly no matter what. I've also noticed that shifting is more smooth once the tranny gear oil is warmed up. Starting out speed shifting first thing in the morning is asking for trouble.

[chris719]

Originally Posted by AlpsRider

There is an art to shifting without over working the syncros. Many people have never shifted a transmission without syncros so it's easy to think that the gears should just mesh perfectly no matter what. I've also noticed that shifting is more smooth once the tranny gear oil is warmed up. Starting out speed shifting first thing in the morning is asking for trouble.

Yes, but it does vary from car to car and transmission to transmission. BMWs seem to be among the worst for this for whatever reason. I have driven various Mazda, 370Z, Mustang, Porsche, and BMW 6MTs for varying amounts of time and the BMWs always have the worst notchiness and shift quality into 2nd gear. I don't even 100% know it's the synchros all the time. I could double clutch into 2nd on my Z4M and still feel resistance.

[AlpsRider]

Originally Posted by chris719

Yes, but it does vary from car to car and transmission to transmission. BMWs seem to be among the worst for this for whatever reason. I have driven various Mazda, 370Z, Mustang, Porsche, and BMW 6MTs for varying amounts of time and the BMWs always have the worst notchiness and shift quality into 2nd gear. I don't even 100% know it's the synchros all the time. I could double clutch into 2nd on my Z4M and still feel resistance.

Lots of people complain of rubbery shifting. I swapped my shifter for the Mperformance one with dry carbon/alcantara which has no padding on the shifter. I feel that shifting is much more precise now but I do know what you mean by notchiness if the shifts. I tend to baby my transmission unless I'm out in the twisties and going for it. In that situation everything is hot and ready to go and I've had no issues.

[F87source]

Originally Posted by LuvMyE92

No CDV on M cars.

That's actually incorrect.

I've also encountered the slight resistance in shifting from 1-2 under WOT conditions but it's not too bad just a slight resistance no gear grinds. If I baby it slightly then it's a perfect smooth shift.

[LuvMyE92]

Originally Posted by F87source

That's actually incorrect.

No, it is correct. You'll have to show me a diagram on RealOEM or similar to convince me.

No BMW M car has ever had the CDV.

[skier219]

Originally Posted by LuvMyE92

No, it is correct. You'll have to show me a diagram on RealOEM or similar to convince me.

No BMW M car has ever had the CDV.

Here's a thread where someone removed it from their M2.

https://f87.bimmerpost.com/forums/sh...t=clutch+delay

[XutvJet]

Originally Posted by skier219

Here's a thread where someone removed it from their M2.

https://f87.bimmerpost.com/forums/sh...t=clutch+delay

Yep. Additionally, ALL F series cars using the ZF 6MT (N55, B58, S55) use the same clutch slave cylinder where the CDV is located. Guys have been removing the CDV from slave in their M235s, M240s, M2s, and 3/4 series 6MT for over a year now.

[XutvJet]

Originally Posted by LuvMyE92

No, it is correct. You'll have to show me a diagram on RealOEM or similar to convince me.

No BMW M car has ever had the CDV.

Look up part number "21526795713 Clutch slave cylinder". Check out all the applications it applies too.

[CosmosMpower]

Not true, I know for a fact E36 M3 had one because I removed one.

[F87source]

Originally Posted by LuvMyE92

No, it is correct. You'll have to show me a diagram on RealOEM or similar to convince me.

No BMW M car has ever had the CDV.

It's not shown on real OEM because it's not a separate part, the cdv is integrated into the slave cylinder, and as you've seen it is present in the m2 from users disassembling the slave and removing it. Also more proof is that the slave is the exact same as non F series M cars, so with due respect clearly you're wrong.

That's also a very bold statement about M cars never having a clutch delay valve, it is also incorrect.

CDV's are present to attempt and protect the transmission, so they're generally present in most if not all manual transmission across all brands.

[F87source]

Originally Posted by skier219

Here's a thread where someone removed it from their M2.

https://f87.bimmerpost.com/forums/sh...t=clutch+delay

Originally Posted by XutvJet

Yep. Additionally, ALL F series cars using the ZF 6MT (N55, B58, S55) use the same clutch slave cylinder where the CDV is located. Guys have been removing the CDV from slave in their M235s, M240s, M2s, and 3/4 series 6MT for over a year now.

Originally Posted by XutvJet

Look up part number "21526795713 Clutch slave cylinder". Check out all the applications it applies too.

Originally Posted by CosmosMpower

Not true, I know for a fact E36 M3 had one because I removed one.

+1
Sorry didn't scroll down far enough on my phone to see these but yes correct.

[chris719]

Originally Posted by LuvMyE92

No, it is correct. You'll have to show me a diagram on RealOEM or similar to convince me.

No BMW M car has ever had the CDV.

What F87source has posted is correct, but it's actually been in more M cars than it has not been in, I think. It's in E46 M3 and Z4M as a separate part even.

https://www.zeckhausen.com/catalog/index.php?cPath=6562

[F87source]

Originally Posted by chris719

What F87source has posted is correct, but it's actually been in more M cars than it has not been in, I think. It's in E46 M3 and Z4M as a separate part even.

https://www.zeckhausen.com/catalog/index.php?cPath=6562

+1
Thanks, maybe they weren't present in the super old M's but I am not sure.
Yeah on some E series they were separate parts hence why the aftermarket sold CDV delete kits, and since they're integrated on the F series no aftermarket kits exist. Unfortunately or fortunately (depending how you look at this and your mechanical skills) the F series CDV being integrated is actually a good thing since deleting it is a free option and doesn't require a replacement part if you're mechanically inclined.

[vale007]

would a short shifter kit helps aswell?

[F87source]

Originally Posted by vale007

would a short shifter kit helps aswell?

Not with the CDV issue, it would exacerbate the issue even more since a short shift kit should speed up shift times.

[LuvMyE92]

Originally Posted by F87source

... so with due respect clearly you're wrong.

I could not find a Homer Simpson "Doh!" emoji.

My apologies for my mistake. I thought (erroneously) that the CDV started with the E46 and continued into the F series (albeit integrated into the slave as noted) but was not present in M cars (I know it was not in the E39 M5 and assumed all others).

The F87 does not act like my F30 340i did, clutch-wise, hence my assumption.

Thanks all for the corrections and for not flaming me as you could easily have done.

[Karmic Man]

Never happened on the 1M but its happening on my M2C quite a few times

Not sure if it's a faulty engine mount allowing the drivetrain to shift under power or the clutch

[mr_lab_rat]

Originally Posted by AlpsRider

Lots of people complain of rubbery shifting. I swapped my shifter for the Mperformance one with dry carbon/alcantara which has no padding on the shifter. I feel that shifting is much more precise now but I do know what you mean by notchiness if the shifts. I tend to baby my transmission unless I'm out in the twisties and going for it. In that situation everything is hot and ready to go and I've had no issues.

You mean just the shift knob makes a difference? Or is there a whole M Performance shifter assembly I don't know about?

[AlpsRider]

Originally Posted by mr_lab_rat

You mean just the shift knob makes a difference? Or is there a whole M Performance shifter assembly I don't know about?

The M Performance shifter with alcantera and dry carbon fiber is just a stick replacement. It is shorter than stock and the knob is without padding. It also has a shape that encourages shifting from the side instead of the top which makes the shift throw even shorter.