Today suddenly I noticed that clutch on my 997.1 Carrera S vibrates when depressed. It happened during driving and I couldn't figure out what is going on. Each gear engagement was hard. I stopped and put the car in neutral. Then I could clearly feel the pedal vibrating when I pressed on it. It kept vibrating until I hit the floor. Same thing happened on the way back. I turned off the engine. Then the clutch felt tight as usual when I started pressing it, but as I kept pressing further, it felt very loose until I hit the floor and then the same happened when coming back. Needless to say but this makes engaging gears hard. I basically have lost the precise control I had on my clutch. It start vibrating and the gears start to engage in very quick back & forth fashion.

I also noticed that shifting gears is harder though I could just be conscious now.

Any ideas what I am in for? How much would it cost?

 

Sounds like the throw out bearing. If it is, then the pressure plate will likely get damaged by it. To me, it's immaterial because it makes no sense to pay for or perform all of the labor required to access the clutch and not replace everything while you're doing it.

 

It turned out to be broken pressure plate (40K miles). Clutch kit had to be replaced but I also got flywheel replaced as it wouldn't have lasted the next clutch life cycle.

I also replaced the transmission lube. The clutch feels much softer now. Is this normal?

 

Soft is normal. As they wear, they get stiffer.

 

+1

 

good to know.

I noticed that now I have a weird hum/buzz that slows down and starts up again as if something is spinning fast, then slowing down and then fast again. It keeps repeating this cycle on and on. This all happens when I am going at constant speed with no changes to throttle and rpm. I have seen it happen on acceleration too. The sound stops if I depress the clutch. The sound is low but clearly noticeable.

Any ideas if this could be related to the transmission work?

 

I have no clue so I'm going to take a guess and ask if it could be your AC compressor kicking on and off?

 

I already tried turning a/c off. It makes no difference. The noise can be heard if I increase rpm while idle. But in that case it follows the sound of the engine: higher the engine noise, higher this noise. But when I drive, this noise seems to go into it's own rhythm.