well i've got 256,000 on this truck JUST today. we have had it since 2002 and i've driven it since 2006. since i've driven it, never have i even done a trans service on it. (i know, shame on me

) from 02 to 06, idk of any service that might have been done to it. i know i put at least 50k miles on it but i honestly couldn't give you a clue as to how much i put on it. maybe 50-100k.
now that you know my life store, what i'm wondering is if i should even touch the thing with a 39 1/2 foot pole? i talked to a few guys. the ford place and another local chain of oil/service places said to NOT flush it and to just go with a gasket/filter change. another guy at the trans repair place said don't even mess with it unless i wanna start fixing stuff.
i really don't know much about these transmissions so any thing is gonna be help to me