87 944S clutch problem

[jmcmath]

My car has 80K miles on it and may be due for a new clutch. Shifting had become somewhat "sticky" lately.

All of sudden yesterday something happened to the clutch and I could barely shift between gears. It goes into gear fine when at a standstill but is nearly impossible shift when in motion.

I've noticed several mentions of this in other postings but cannot ascertain if such a problem is more likely to require a new clutch or some sort of work on the master and/or slave cylinders.

If the cylinders should be the first thing to look at where are they located?

Any and all suggestions appreciated.