When do you change manual tranny fluid?

[Tedster]

So ya, I'm wondering when I should change my manual tranny fluid?? I have an 01 Protege, has 157k miles, and have had it since around 135k. Not sure if the guy before me did it or not. It drives fine and the tranny is smooth. I've had other Mazda's before and have replaced the fluid at the dealer and after that, it just wouldnt shift the same, not very smooth, hard to get into 1st... it was very weird... why would they do that? You'd think it'd shift better after a change.
Thanks guys.

[BlackCherry06]

It depends on what they changed it to, and changed it from. It it had a high quality fluid like Redline MT90 and they changed it to whatever crap dino fluid the dealer buys cheap, shift quality could suffer.

If it were me and I couldn't verify service history, I'd crawl under there and dump it, and put in MT-90. It's cheap insurance and peace of mind. And if he never changed it, it's definitely ready.

[Tedster]

Yea sounds good, makes sense. So how hard is it to do? Do you pour it out and put in the new stuff thru the same plug? Probably need one of those pumps to pour it in with? Thanks.