Clutch Noise Root Cause Confirmed

The new owner decided to install a five speed Miata transmission in his car.  This also gave him the chance to address the occasional squeal issue with the clutch.  This squeal had continued over the last several years but at just every once in a while and only when the clutch was partially engaged.

Today we removed the engine and transmission and were able to fully inspect the clutch.  We are now convinced the root cause of the squeal was a mouse nest.  The clutch plate had lots of fuzzy material stuffed into the base of the fingers of the clutch.  Here's a picture:

That brown dusty looking stuff between the fingers is not supposed to be there.  Interestingly, the clutch disc had very little wear on it.  And probably the clutch plate could be cleaned up and reused.  But we are not taking any chances because we don't want to pull this transmission again.  So it's getting a new clutch plate to go with it's Miata clutch disc.