ok a little background, I have a 2010 f250 super duty Lariat edition, about a year ago I noticed a thump when stopping and taking off. I can only feel it nothing can be heard. I have taken the truck to the same dealer now and this is what all has been done to the truck. Regreased the joints and piņon yoke, was told after that did not work the the planetary gears in the tranny has a little play and that it was normal to feel a slight thump, then again with a regrease with a different kind of grease because of a TSB, finally replaced the entire drive shaft assembly (2piece assay.) and that worked for a bit but the thump is back. Anyone know what is going on?