should i change my automatic tranny fluid? owners manual says to change it every 100k/10years BUT if you are on a severe maintenance then every 2yrs which seems like a huge fucking difference

Better safe than sorry.

>>28461050 (OP)
Every 50k miles is reasonable

>>28461050 (OP)
Drain and fill it at least, if it's never been done consider dropping the pan and changing the filter as well. That'll also let you check the pan if it's got a magnet so you can see if it's got any wear or not.
"Flushing" and using a machine to do it are what you never do, on the other hand. I'm convinced that the "old ATF is holding things together" meme is just an old wives tale by an Aamco employee looking for more business.

>>28461050 (OP)
Yes and if your transmission has a filter change that too.
Some do, some don't. Some have 2.
Many automatics do not have a drain plug so be ready to drop the full pan.
You may be able to suck some out through the top, but a flush machine can fuck your shit up, so do it carefully or with a hand pump.

Just got mine flushed four times because the $100 amazon radiator let a bunch of coolant into the transmission, here's hoping it doesn't crap out on me during the three different road trips I'm taking it on later this year

>>28461050 (OP)
I change it every time I change my oil