2002 2.7 Vibration/Noise

[germaneighter]

In the last week or two I have noticed a vibration under acceleration. I have experienced this occasionally on an intermittent basis for about two years but now it deems constant. Then in the last couple days I have noticed an additional different vibration/noise while decelerating. (Sounds like a bowling ball rolling down a lane.) The frequency is speed related, not engine RPM related. I can put it in neutral and the sound/vibration does not change. Engagement of the clutch does not alter the vibration/noise either. I was thinking motor mount but it seems that would be directly RPM related. Any thoughts?

thanks