How important are trans fluid changes?

[BUTCH1]

My Altima's CVT has a dipstick tube hole with a cap, but no dipstick. It also has a drain plug, so that part is good at least.

You basically have to measure how much you take out and replace that same amount with new fluid. I'll probably aim at changing or at least checking the "deterioration level" when I hit 30K.

That's how I wound up doing it, just keeping the fluid drained and replacing the exact same amount. I would recommend doing it with cold fluid as possibly hot fluid might "expand" some and result in an incorrect re-fill, IDK, I'm just guessing, dumbest thing car makers ever did, as cars get older have a lot of us not had vehicles that leaked a little fluid?, most people would just keep tabs on it and add as needed vs replacing a front seal that might cost $1000 to do, now that option is gone..