The dampener is 3 pieces. Base, Rubber collar. Outer ring. They wobble with age. Idle the engine and look to see if it is wobbling. The p0128 means the thermostat is stuck open. On the 05 to 07 duratec, the easiest way to replace it is to remove the passenger side headlight and work through the opening.Just to clarify, are you talking about crankshaft walk or too loose in the dampener?