I believe you may have just led me to the cause.
When I was trying to remove my alternator to address the charging issue earlier this year I bent that little strip of metal on the front of the fan. At the time, I briefly considered removing the fan/clutch assembly to give me more room to try to work on the alternator. I bent the strip thinking it covered a screw on the front of the fan...
I doubt I'll be able to bend it exactly into the right position...