FYI: The throwout bearing is not pressed on... The throwout bearing comes off with a pair of pliers for the wire retaining clip and your hands and the pilot bearing can be pulled with a $10 puller or hydrauliced out with a piece of rod and some grease in the cavity. You don't need a machine shop for this stuff.
Anyway I had a funny noise like that once and it was a dry goofy throwout bearing.
