Shaking or judder while releasing clutch pedal from a stop.

[Loach]

535i 5 Speed. This only happens when the vehicle has been sitting and is cold. The problem stops after driving for about 10 minutes. As soon as I begin to release the clutch in first gear from a stop, there is a very noticeable shaking and judder as if the clutch is having trouble grabbing.

Car has been doing this intermittently for about a year and a half, but recently has been much more prominent and the shaking has gotten worse. Clutch has about 20k miles on it, but I'm not sure if the previous owner replaced the slave or master cylinder or other components of the clutch system during that time.

My question is, how sure can I be that this is clutch related or driveshaft related? I have had the intermittent slight shudder while accelerating from low RPM since I've had the car. Very noticeable in first and second gear, but that's obviously when my foot is off the clutch pedal.

I'm hoping that since this only happens when the car is cold that this could give me a clue of where to look first. Clutch pedal feels fine and there is absolutely no indication of a problem after about 10 minutes of driving.

UPDATE: Clutch pedal just went to the floor. On my way back to mr. searchy.

UPDATE 2: Clutch helper spring unseated itself, causing it to dig into and puncture the master cylinder hose while the clutch pedal was depressed. Swapped the new master and slave and hose line and I'm up and running. Noticed a well worn transmission mount while under there, and will replace the pair to see if the shudder goes away.

[dsmith]

Sounds like you might have two issues. The easier one is probably driveshaft related (shaft, CSB, Guibo), where you have a 1st/2nd gear acceleration shudder.

The clutch shudder issue is probably a disc/flywheel surface issue, since it goes away once heated up. Could be from not surfacing the flywheel at clutch change or improper clutch usage or fluid/grease on the disc. There is always a possibility of another issue, but you'll never know since the surfaces are already affected.

I would say give it a little slip for the first couple of first gear starts and see if it goes away with some heat in it. Live with it until you just can't stand it.

[Loach]

Took the kick panel off to take a look. Pumped the clutch a few times and it just lost all resistance after about 4 pumps, right on schedule I'd say. At least now I know where to start looking. No fluid loss though, nothing under the carpet. I'm thinking master and slave weren't replaced with the previous job. Will also check for cracked bracket.

[Mike W.]

Bad, soft or broken, motor or transmission mounts will cause clutch shudder, along with a flywheel that needs to be surfaced or a dirty clutch disk or warped pressure plate.

[trevmmeister]

Had a similar problem quite a few years ago when I first got my '88 e28. Since then the clutch, master cyl, slave cyl, trans mounts, diff mounts, and engine mounts have all been replaced. Smooth as butter as of now. Just several simple(not really) yet relatively cheap fixes, could solve it? Please feel free to correct me if I'm wrong.