in the 93 w/o dipstick, though not 'lifetime fluid' Bentley gives an elaborate procedure to get the ATF to temp, then drain, then fill, bring to temp, check level, repeat until level is correct......

If all the ATF is at the same temp, (ATF in the tranny and new ATF in the bottle) why can't I just drain x amount and refill w/new ATF of the same quantity? I could do this first thing in the a.m. when all fluid temps are equal, ideally making the drain and fill process much simplier.

Am I missing something, or is this an acceptable method?
Thanks, Rob sends....