I have the same problem with my 2001 Explorer Sport V6. Had the
"Transmission Serviced" at the 30,000mile dealer service interval.
They screwed it up Real Well. I think they put ATF in instead of the
"Mercon-V(5)" fluid that the dip-stick requires to be used. The Dealer
still didn't fix the shudder, and my fuel mileage went from 330mi/tank
to 230mi/tank. NICE. So Don't get your transmission back flushed and
serviced, this will not fix the problem.