Just food for thought. Have you run a search on the transmission topic in the 09+ F150 Forum? You might want to...same 6spd tranny in the Expy's as the 09+ F150 trucks. Might be worth a gander and some reading.
Additionally, what you've stated here...
Originally Posted by
backdr10
So I drive the truck home and there is no longer a vibration through the gas pedal on acceleration and the truck is not pulling-instead I put the gas pedal to the floor and the truck goes nowhere. It revs up and slams into gear and takes off. I made it home and now the trans is slipping between 1st and 2nd gear. .
...might very well be contributed to the drive by wire lag that the 6spd exhibits. Gone are the days of an actual throttle cable. Everything is now sensors and computers which take a little longer to react.
I wish you well in your search for answers.