I guess a dual mode dampener should be installed to eliminate "crank whip". What is crank whip? Can you hear it and if you can hear it what does it sound like?
"Crank whip" is crankshaft bending/flexing that occurs especially at high RPMs. It causes premature bearing wear which can lead to spun bearings and broken rods. It is a particular problem in the Duratec as I understand because Ford shortened the crank from the original (Porsche) design without propererly compensating for it. The dual mode damper is the compensation, developed by Ford's OEM damper supplier to fix the problem (it is now found as OEM on new Duratecs equipped with the MTX). You can feel crank whip..the Duratec is pretty smooth but install a DMD and you will realize that the high RPM band is now noticeably smoother. My advice,,just do it.
