Greg- unless the neighborhood urchins really DID put rocks down your defroster vents, the noise comes from the blades hitting the housing, as there are plain-bearings on the motor, not ball bearings. The dual fans and motor CAN be removed without pulling the dash. Jim Kuehne of Nor-Cal showed me; up to that time, I didn't believe it could be done. And Jims hands are twice the size of mine- a life of construction work, I suppose. Anyway, get out youre Parts Manual and study the layout of the fan hold-down. Its a split clamp. Because none of the 3 bolts can be seen while you're working on it, you'll be working blind. Likely, all you'll have to do is slightly shift the motor and impellers to one side or the other to make the noises go away.
