1 st time on forum. I have 2007 c6 6 speed with 1750 miles.since day I had a knock or thump in shifter .While resting my hand on stick and feeling this thump-thump-thumpis the only sign that something is not right .Did any one have the same thump or knock .Been drining a stick since 1965 -wow I am old ! Any help or coments ? Have an appointment next week .

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