anecdotal data - 1st auto trans fluid flush @ high mileage

hey everyone, i've been doing a lot of forum-scouring to try and reach, at least, a personal conclusion on where i stand on the controversial topic of flushing transmission fluid for the first time at high mileage (or rather, much later than suggested in scheduled maintenance guides.) the opinions range from very affirmative all the way to very opposed. after a whole day, i've yet to reach a comfortable conclusion and have decided to approach it differently.

instead of theoretical or logical opinions (which i've read enough of), i'm asking for people who have done their truck's first FULL transmission fluid flush and replacement (not just a partial drain and refill) after, let's say, ~100k to describe their process and results in this thread. it might be useful to mention the brand of ATF used, method used, if the filter was replaced, how the fluid looked or smelled coming out after x miles, etc.

i will also post a poll to see if there might be a convincing broad consensus that sways one way or another. looking forward to getting some good field-tested knowledge

 

decided to go ahead and get a flush done. this was at 121,300 miles, about 100 miles ago and so far, everything's running smoothly! ever since a gasket replacement on my transmission at 119k, my truck had been acting just a tiny bit funny- sometimes when i would come to a stop, it jerked a little, kinda felt like missing a stair on your way up. after the flush, this problem is gone!

the other positive is that now since my truck has been completely flushed with the updated T-IV, i can start doing just drain-and-refill's at home for very cheap. i was discouraged to do this before because i wasn't sure what the previous owner had in it, and the FSM i have still specifies the old ATF.

overall, i'm very happy i decided to get this done even after 120k for the truck's first time