Where Is Your Clutch Engagement Point?

[ryanb328]

2018 M3 Comp 18k miles 6MT.

After a day of the usual "hard" (for me) street driving (a few shifts at close to redline), I noticed the car didn't feel the same. I can't get a smooth 1-2 shift anymore without REALLY babying the clutch release (feels like it grabs the gear but then I'll almost feel a second clunk/lurch/grab at the top of travel - maybe this is just the transition from shift to gas again - but I don't remember it doing this before). Clutch engagement point feels like it's an inch or so of the top of the pedal travel, but I don't remember if it was high to begin with and my issue is somewhere else (Driveline slack for some reason?).

So, where is your clutch engagement point (how far up from the top/bottom) & can you get a smooth 1-2?

Any comments on the "driveline slack" feeling are appreciated.

Thanks

Edit: Relevant just got a new trans under warranty because of an occasional catchy 1st and grindy 2nd at WOT. I asked them to look at the clutch and they "reported no problems".

[swagon]

Originally Posted by ryanb328

I can't get a smooth 1-2 shift anymore without REALLY babying the clutch release (feels like it grabs the gear but then I'll almost feel a second clunk/lurch/grab at the top of travel - maybe this is just the transition from shift to gas again - but I don't remember it doing this before).

Sounds to me like you are letting the clutch out too early and slow when the engine revs are still not at the optimal point for the next gear. The car lurches forward/bogs and makes a noticeable clunk.

1st gear is pretty short anyway so it's pretty pointless giving her the good ol' one-two as if it was a mustang. You're better off short-shifting into second, but slower than now.

Clutch in, off the gas and wait till the revs drop to the point where the auto rev match holds the revs. You'll notice it takes a while because the RPMs don't fall very quickly and the difference in gears is rather high, but it will be a smooth shift indeed. If not, check your drivetrain. Rubber mounts in the rear diff, gearbox (should be new now then), flex disc, etc. Idk, not a mechanic myself lol.

[brocurls]

I plant my heel onto the floor mat when clutching in. After I shift gear, I keep my heel planted but arch my foot up as much as I can. For me, that's where the clutch grab is.

I do feel like you have to baby the clutch if you're going to blast off, even moreso when you're in S+, or else you get that shift shock.

I generally shift into 2nd somewhere between 2-2.5k rpms because anything higher, I have to ride the clutch a teensy bit longer to get it smoother shift.

[ntg44]

Strange. I don't see how this scenario is even possible with auto rev matching. Assuming rev matching is enabled, all that needs to be done is wait for the revs to drop until the RPMs settle in the next gear and let the clutch out with no throttle applied. Perfect upshift every time with no shift shock other than letting off the throttle to change gears. Unless you are driving without rev matching, which I believe on a 2018 means that either you have TC off all the time or have it coded out. Maybe you can clarify so we can isolate the issue.

[ryanb328]

Originally Posted by brocurls

I plant my heel onto the floor mat when clutching in. After I shift gear, I keep my heel planted but arch my foot up as much as I can. For me, that's where the clutch grab is.

I do feel like you have to baby the clutch if you're going to blast off, even moreso when you're in S+, or else you get that shift shock.

I generally shift into 2nd somewhere between 2-2.5k rpms because anything higher, I have to ride the clutch a teensy bit longer to get it smoother shift.

Thank you for this. I prefer to shift into 2nd at 3-3.5k to stay with traffic, so maybe thats part of my issue. If you drive your car soon, mind seeing if you can tell how far from the top of the travel it grabs the gear?

Originally Posted by ntg44

Strange. I don't see how this scenario is even possible with auto rev matching. Assuming rev matching is enabled, all that needs to be done is wait for the revs to drop until the RPMs settle in the next gear and let the clutch out with no throttle applied. Perfect upshift every time with no shift shock other than letting off the throttle to change gears. Unless you are driving without rev matching, which I believe on a 2018 means that either you have TC off all the time or have it coded out. Maybe you can clarify so we can isolate the issue.

This is sport and efficient. I will note that I shift 1-2 at 3-3.5k. Basically, if I do what you are describing (wait for the revs to settle where they should be for the next gear), when I let the clutch out it almost seems like the rev-matching releases the revs where it THINKS the clutch should be grabbing so that it is smooth, but it doesn't actually grab until a little later and the "lurch" I feel is the +100-200RPM correction. I'll see if I can get this on video.

[Humdizzle]

BMWs are notorious for a notchy 1-2 shift. I think i shift around 2500 into 2nd, but mainly you just have to slip the clutch a bit slower than other gears to smooth it out.

you mentioned a 'grindy' 2nd gear shift. Maybe your syncro was gone?

I have rev match coded off for sport, and on for sport+. Usually drive in sport.

[Aaaaaaaaa]

Could be related to your recent trans replacement maybe? 1-2 shift in these cars are sometimes frustrating due to the long rev hang.

[zorrro]

So this happens after hard driving but eventually ie next day its fine? What about with rev match on?

Do you have a clutch stop installed? I have one and love it but in my first install I mustn't have pushed it on straight and it eventually got pushed over so it was as if nothing was installed.

I have '18 mt 10k mi and never experienced what you feel. I've gotten pretty lazy though and mostly leave rev match on.

[G35POPPEDMYCHERRY]

the way the revs drop during an upshift especially 1to2 is quite a head scratcher in the car. feels way to slow. but im used to it

[Ray Khan]

ryanb328 my car is at 900 miles and the clutch engagement point is pretty much at the last 25% of the pedal travel. I haven't drive too hard all that much so far, but I'm also learning how to best shift from 1 to 2 when going wide open throttle.

[Fat Goose]

Sounds like the clutch delay valve (bmw trying to save the clutch from inexperienced drivers), harder to remove on this car than previous models, but not too bad and its a MUST! You will be driving silky smooth in 1st and 2nd, wondering why it took you so long to take it out

[9M71]

Originally Posted by Rmnelson12

Sounds like the clutch delay valve (bmw trying to save the clutch from inexperienced drivers), harder to remove on this car than previous models, but not too bad and its a MUST! You will be driving silky smooth in 1st and 2nd, wondering why it took you so long to take it out

Is this something you can code out or the actual valve has to be removed?

I notice my clutch behaving funky after being in stop&go traffic for 30+ minutes. Maybe it's the left leg giving out, but definitely never experienced this before in prior MT cars.

[Fat Goose]

No coding, have to get under the car
There are some DIYs around, this one for the M2 is good:
https://f87.bimmerpost.com/forums/sh....php?t=1625114

[ryanb328]

Originally Posted by Humdizzle

BMWs are notorious for a notchy 1-2 shift. I think i shift around 2500 into 2nd, but mainly you just have to slip the clutch a bit slower than other gears to smooth it out.

you mentioned a 'grindy' 2nd gear shift. Maybe your syncro was gone?

I have rev match coded off for sport, and on for sport+. Usually drive in sport.

Hey, yeah 2nd ground 1 out of 10 WOT pulls, and it wouldn't go into 1st often, but this clutch thing was happening before that. I'm sure it was the synchros, but they replaced the trans and thats all fixed up now.

I'm wondering HOW you can get up to speed shifting 1->2 at 2500. SHARE YOUR WAYS.

[ryanb328]

Originally Posted by InTheseUncertainTimes

Could be related to your recent trans replacement maybe? 1-2 shift in these cars are sometimes frustrating due to the long rev hang.

Funny you say that. I put 16,000 miles on this car since probably November 2019, so I am very familiar with how it used to drive, which is a good thing and a bad thing. It was also doing this before the trans replacement but I will humor the dealer by doing the 1,000 mile break in. Sport+ is basically un-driveable now. And I've probably put over a million miles on manual cars so that says something. The clutch engagement point is actually higher than my 100k mile E90 and my 200k mile E46.

[ryanb328]

Originally Posted by zorrro

So this happens after hard driving but eventually ie next day its fine? What about with rev match on?

Do you have a clutch stop installed? I have one and love it but in my first install I mustn't have pushed it on straight and it eventually got pushed over so it was as if nothing was installed.

I have '18 mt 10k mi and never experienced what you feel. I've gotten pretty lazy though and mostly leave rev match on.

No, this is something that happened after 1 specific pull and since then for the past 1,000 miles and counting, clutch engagement point moved upward and now I can't shift 1-2 smooth. And no clutch stop. And yeah, I feel like its not normal, but because of COVID, they won't let me come on a test drive

[ryanb328]

Originally Posted by Ray Khan

ryanb328 my car is at 900 miles and the clutch engagement point is pretty much at the last 25% of the pedal travel. I haven't drive too hard all that much so far, but I'm also learning how to best shift from 1 to 2 when going wide open throttle.

Thanmk you!! This is really helpful. If my engagement point is fine (not sure how SAC would've gone all the way to the end when they checked the clutch and it was fine), so maybe my problem is diff or driveshaft related.


Anyone else who can tell me where their clutch releases (last 25% etc) is welcomed!!

[brocurls]

Originally Posted by ryanb328

Thanmk you!! This is really helpful. If my engagement point is fine (not sure how SAC would've gone all the way to the end when they checked the clutch and it was fine), so maybe my problem is diff or driveshaft related.


Anyone else who can tell me where their clutch releases (last 25% etc) is welcomed!!

I agree, the grab point is maybe 3 inches from clutch wall.

If you're just putting around, shift under 3k, with a split second pause on the engagement point with no throttle.

If you're trying to WOT from 1st to 2nd and above 3k rpms, you will have to hold it at the grab point for a half-sec longer with no throttle input to get a smooth shift. This applies to me regardless if I'm in E/S/S+.

Then again, if you're WOT, I don't think you'd care about shift shock at that moment.