Originally Posted by Pete
I change the atf in my toyotas every 10K.
.... I have well over a million miles on 6 toyotas and have never had a single problem...
Originally Posted by 73ss454
I think it's a good idea to change the fluid at 30K. Some manufacturers say not to change the fluid for the life of the car. I've always done it and never had a problem.
Let me point out that no cause/effect can be determined form these types of reports.
IOW, changing more often than the manual states and not having problems doesn't mean that the action led to not having problems. You may have not had problems had you followed the manual (as LOL! reported below).
I've never gone beyond the manual my whole life, and mostly have had automatics. Only trans problems were the generic 1st gen Chrysler van (fully covered by Chrysler), and a little, very occasional slip in a Buick that seemed OK after adding some kinda 'goop' for transmissions. Would that minor problem have not occurred with more frequent changes? Who knows, but that would be a lot of time/money in all those cars all those years for a chance to fix a very minor problem that was fixed with a $5 can of goop. And wasting that trans oil seems like a bad environmental move (even if recycled - that takes energy/resources).
Now, if someone has data that shows doing 2x the manual extends life, provides better mpg or something (or not) - THAT would be meaningful.