Check the steering rack and see if the rubber bushings are worn. It could be that the rack is touching the metal bushing retainers when turning quickly, and transmitting the vibration. This would account for the intermittent noise.
Pete...
2004 Mercury Marauder 300A
Black Clearcoat/Dark Charcoal LEATHER
DOB 10/31/2003
DOP 1/2/2004
www.mercurymarauder.net
