My apologies for dragging this topic slightly off-topic, and please excuse my ignorance as I've never actually done this on a car before (done it on lots of motorbikes...), but when one splits the engine and gearbox to get at the clutch is it necessary or desirable to drain the engine and/or gearbox oil?
I'm guessing the answer is no, as long as the crank and gearbox oil seals are doing their job, but thought it best to ask...