tosha

Hey guys, I'm in the process of installing a lightweight flywheel and new clutch, and found some strange notches inside the housing of the flywheel. Any ideas what could cause it? Did a mechanic some time ago forget something in it? Have you seen anything like this before?

nine9six

What does the clutch, flywheel, and other rotating internals look like?

deutschnine

pp000830

Could some of the abrasive lining or maybe some lining mounting rivets came loose when an old clutch came to the very end of its life? The debris could have found its way to the edge of the flywheel where it brushed against the case until it ground up and spit out. I don't see it as a big concern as all the debris is gone now and it doesn't look like anything other than cosmetic damage.
Andy

tosha

It looks like the clutch was changed in 2000, when the car was four years old, probably around 40K. There was almost no visible debris inside the bell housing, except for maybe on small metal fragment. Here's what the disc and plate looked like.

pp000830

Could have been caused by debris from the originally installed factory clutch, we will never know for sure.
I got 80K miles out of my 993s original clutch. Some get less but 40K seems like a short life for a clutch.
Others experiences?

Seamless

Is it possible that this is just imperfections from the original casting process?

911-TOUR

Interesting. This looks like the pitting I had on the fan blade on my 993 before it cracked and I had to replace. Is the G50 case a magnesium alloy?