540i 6-speed factory clutch pedal initial engagement / disengagement point?

[m60power]

For those with a 540 with an oem clutch / 265mm flywheel / slave cylinder, how far off the floor is your clutch pedal's initial engagement point? I've noticed my clutch engagement starts really low down; it doesn't fully disengage until the pedal is barely 0.5" from bottomed out against the floor stop. I can't remember if this is typical or not? I recently had to bleed the clutch hydraulics again when removing the transmission to switch to the oem dual mass flywheel from the single mass flywheel I installed a couple years ago.

I'm not sure if the clutch engagement travel range was always like this or not? it may have been, and it's possible I just never payed any attention to it. When the car is on the ground I can feel it start to grab just off the floor, and with the wheels off the ground and in gear, the rear wheels start to spin when the clutch pedal gets to about a half inch from the floor stop. When I initially installed the old flywheel I had also checked for full clutch disengagement then with the wheels off the ground (to verify I was able to fully bleed the system), but I don't think I noted where in the travel the clutch disengaged...

I know the oem 540 265mm clutch pedal feel is pretty light by BMW standards because of its larger diameter slave cylinder (and therefore less pressure plate displacement for a given amount of pedal travel compared to using a smaller diameter slave cylinder bore).

The clutch seems to use most of the pedal travel to fully engage it too. Is this all normal for the stock 540 setup, or is it possible something else is off, like air still being trapped in the system after bleeding? I also made sure to replace the pressure plate bolts with new ones when I put in the new flywheel.

[m60power]

Shamelessly bumping this thread to the top

[GazM3]

May be a bleeding issue or the clutch pedal itself may need adjustment. All I know is there are 2 adjustments on the pedal, one for the stop and one for something else. Others may chime in. Clutch pedals are notoriously difficult to bleed. Often Ive had to resort to reverse bleeding from the slave, as this way you are going with gravity

[m60power]

I don't have a pedal stop adjuster installed on the pedal frame, just the little rubber plug bumper in that hole. That rubber stop is only 2mm thick. The other clutch pedal adjustment is the eccentric shaft bolt that attaches the master cylinder rod end to the clutch pedal arm, this adjusts the height the clutch pedal sits at, I currently have it adjusted all the way up.

I did the reverse bleed method by pumping the fluid up from the bottom when I first installed the clutch master / slave cylinders, hydraulic lines, and reservoir and hose with all new components. This time around I did it the more traditional way, but I still removed the slave from the bell housing to compress the slave piston with bleed screw cracked open. However, as I mentioned above, I don't recall if the engagement point was actually any different that first time I bled the clutch system from the bottom up a few years ago.

[///Manuel]

3.8 or 3.6 clutch pretty close to bottom floor yes. Responsive! No need to change the clutch stop

I did have bleeding issues but that lead to pedal to the floor and not coming back up at some point.

Usually air won't let you disengage enough and feel spongy. No air = firm clutch and quick engagement, little play between off and on.

[anonoh]

I think your experience is as expected for a factory setup. When I had the the original 265mm DMF and 27mm slave cylinder in my car, the clutch engagement bite point was very close to the floor. This was the case even towards the end of it's life when it was slipping badly.

I recently switched to E39 M5 setup with a 240mm SMF and 22mm slave cylinder and now the engagement bite point is almost all the way at the top of the pedal travel. The complete opposite of what I was used to before. I find it difficult to drive it smoothly as it is hard to modulate the clutch especially in traffic. I was going to post my experience in the big 540i/6 clutch thread but haven't had the time yet.

[m60power]

I think your experience is as expected for a factory setup. When I had the the original 265mm DMF and 27mm slave cylinder in my car, the clutch engagement bite point was very close to the floor. This was the case even towards the end of it's life when it was slipping badly.

I recently switched to E39 M5 setup with a 240mm SMF and 25mm slave cylinder and now the engagement bite point is almost all the way at the top of the pedal travel. The complete opposite of what I was used to before. I find it difficult to drive it smoothly as it is hard to modulate the clutch especially in traffic. I was going to post my experience in the big 540i/6 clutch thread but haven't had the time yet.

Thank you for that insight, so it sounds like that's normal for OE 540 running gear... The stock e34 540 large slave cylinder diameter definitely makes the clutch engagement super easy, I just couldn't remember if it was typical for the full range of the 'bite point' to be that long of a travel distance, such that it starts with the pedal near the floor. My e36 is quite the opposite, like what you describe with the 240mm flywheel and 25mm slave, where the bite point is high up in the travel (~75% up) and the total start-to-end engagement distance is a much narrower window of pedal movement.

It feels odd to have to kick the pedal to the floor for full disengagement of the clutch, however if I'm slowly taking off from a stop I often modulate the pedal without even touching the gas until the clutch pedal is all the way up. The car smoothly gets going which is really nice in traffic or parking lots.

[amoebamonster]

I recently had a very similar problem in my 6-speed 540. It turns out that the slave cylinder that was shipped to me had the wrong length of engagement push rod. I bought an oem unit and compared the two and the first one was about 6 mm longer and made the engagement point very strange and difficult to drive. I hope this is helpful

[m60power]

I recently had a very similar problem in my 6-speed 540. It turns out that the slave cylinder that was shipped to me had the wrong length of engagement push rod. I bought an oem unit and compared the two and the first one was about 6 mm longer and made the engagement point very strange and difficult to drive. I hope this is helpful

That's an interesting bit of info, although I don't think I have that same issue. I bought a new slave cylinder directly from BMW, and its push rod was also the same length as the used slave cylinder that came with the old 420G transmission (from an e34 540i) that I had originally swapped into my car.

Does your 540i have the stock 265mm flywheel and clutch in it? If so, how far off the floor does the clutch pedal start to engage the clutch?

[m60power]

An update - I somewhat recently drove my brother's e34 540i 6-speed, which does not have too many miles on a recently replaced clutch, flywheel, and pressure plate and I observed that his car exhibits the exact same behavior as my e32. The clutch begins to grab with the pedal just a little bit off the floor and the engagement period takes up a large range of the pedal travel distance before entirely released, so I'm inclined to believe this is the normal behavior for the factory setup. This makes sense based on the large diameter bore of the 540 slave cylinder which will give a lighter pedal feel but less displacement for a given travel distance of the clutch pedal master cylinder (more clutch pedal travel to fully disengage the clutch disc).