Was driving on highway, trans has been slipping in higher gears for the past year or so, and I floored it to pass someone and it just let go. Coasted to the shoulder where I got no movement in any gear selection (auto trans) and no change in 4hi/4low. When I shift from park I hear no noise internally and tac does not move at all. Is it safe to say it is most likely the trans? I started pulling drive shafts but don't wanna pull everything until I am pretty confident what it is.