I notice my transmission in my 03 Lariat (4R70W/4.6L/ 12K miles) occasionally shudders or vibrates after stopping and starting a turn, or, when starting out in 1st. I don't drive the truck hard, and it has done this since day one. Does not have any issues at higher speeds. The buzzing noise is definetely there, and I can feel when it happen in the accelerator pedal. I know it is not right, but it doesn't happen all the time. If I take it back to the dealer, it likely won't repeat until I drive home. What could this be....

slipping?....I am hardly pressing on the accelerator
fluid?......level is perfect

Help!

Greg
(Marietta, GA)