yes the synchromesh fluid type is the is what it wants.
i feel sorry for anyone who gos to a lube shop and they put the wrong type in.
the jeep shifts like crap, i got the jeeps first fluid change at a lube place and they put some kind of atf in, it felt like crap driving it.
i looked threw the book to find the fluid type but it's the only one missing. i found someone elses post on here saying to use synchromesh fluid, so i did because it couldn't be any worse then it was after the lube place.
wish i could get royal purple in canada, so i found pennzoil synchromesh for 15$ a bottle, put it in my jeep and it shifted like the day i got it again, yea!!
i guess the hole point of the message is the 6 speed needs a synchromesh fluid type, if a lube place does it for you ask if they have it. or do it your self.