I had some rattles around the heat shield that runs the length of the coach...I discovered (and can now see even more clearly in Earl's construction piece) the aluminium "stiffner" that is screwed from the top down, it comes loose with the heat and rough roads and rattles like mad, I have screwed up thru the sheet steel into the square stock with some self tapping lags and have stopped all of the rattling, atleast for now. Not sure why PC does not tack weld apiece of angle vs's the way they have done it?....If you reach above the shield mid ship you will feel the 1"x1" square stock, if it is loose it may be what is the sourse of many rattles you are hearing in the cab. Thanks, Ron