Ok I posted this in another thread and then realized it was for the Mazda 6, and the last comment was in 2007 so I hope this is a better place for it:

I have a 2005 Mazda 3 with 140k plus miles on it and I never serviced the transmission (automatic). The reason I didn't is because the owner's manual doesn't specify any kind of service for it. So I thought it might be a sealed transmission? But it has a dipstick so I'm confused.

Am I pretty much screwed as far as transmission life goes now? I don't even check the fluid because I'm afraid. What are your suggestions? I don't understand why the owner's manual wouldn't say ANYTHING about servicing the transmission.....

 

Some folks will say drop the pan, change the filter and top off the fluid (which I recommend), other folks will say if you've gone that many miles you're better off leaving well enough alone and driv'er till she drops, and still other folks will recommend a transmission flush (something I never-EVER recommend; kills way more trannys that it saves).

The thing is, your car came from the factory with synthetic transmission fluid, and unless you drive the snot out of it, the fluid should probably be good for the life of the car.

 

Thanks shipo...yeah I probably should service it. What I'm pissed about now is a few years ago when the car was still under warranty I noticed kind of a jerky shifting when it was cold...sometimes still does it. So when I went to my local Mazda dealer for an oil change I mentioned the problem. They couldn't duplicate it so all they said was "your transmission fluid is brown" and they recommended a service.

Looking back I wish I had been more assertive and insisted they do something under warranty...all they wanted was money for the transmission service...I should have pointed out that the manual didn't specify the need for a service, and since it was under warranty I definitely didn't have enough miles on it for it to need new fluid.

I got to thinking about this more yesterday because as I was accelerating to get on the freeway (not cold) the transmission did such a huge jerk when downshifting it felt like I'd been hit. Now I'm worried.

Sorry about the rambling. I guess I'll just put all that behind me and change the fluid and filter already.