Occasionally, as I release the clutch pedal there is a brief sound and,
strangely enough, a matching vibration felt in the pedal itself.  It's about
the same frequency as a vacuum cleaner in pitch.  It reminds me of the noise
made by an electric fan when the propeller is loose on the shaft - a
harmonic vibration which is short lived and unpredictable.  

I have tried to be careful when shifting, but I don't seem to be able to
decipher what conditions or actions of my own are responsible.  Does any of
this sound familiar at all?  Is it time to rebuild the clutch, or is there
an adjustment necessary?

Thanks,

Matthew Snook
'84 1.9 Westy�