I drive a manual Skoda octavia. for some weeks now, I've been having issues. I have had to replace the slave clutch cylinder ( I hope that's the name);( the one mounted on the gear box) three times in two months now. the third replacement just gave way today and I have been informed that the reason is that my clutch plate and disk are worn.
before the third clutch cylinder gave way today, I had the following symptoms; difficulty getting into third gear and crunching sound when getting into second gear.
before the second one gave way, I experienced massive juddering when setting off from a standstill. this stopped after I replaced it with the third one that has just packed up.

is the theory about the clutch plate and disk being worn true?
must I change the release bearing as well while changing the clutch plate and disk?