I am scratching my head over this one. A few weeks ago, I noticed a vibration/shudder when starting to roll from a stop. The problem takes place in either drive or reverse at low rpm's. It is felt when I lift my foot off the brake and let the truck move under its own power. I also feel it when I am coming to a stop. If I go from brake to gas, no shudder. There is also no shudder felt at any other time. The tranny seems to shift smoothly. I have ~80k on my 2001 F150 4X4 with the 5.4L and 3.55LS axles. The dealer has verified the shudder, and has been working with Ford to try and figure it out. They already checked/lubed the driveshaft. Anyone have any ideas on this one? Thanks in advance.