best way is to remove derby and look.
But I would say it was rubbing on the fingers of the clutch plate basket.
The basket is an aluminum type material.
Never had any problem with my plug leaking or going into far, and yours looks like the
one on my 01 and 06.

 

Thanks for the garage complement USMCBay. Just finished the garage project last month. Been talking it up for a couple of years, but finally did something about it around Labor Day.

 

Do you ever get accused of hanging out in there TOO much... I know I would~ LOL! Great work!!!