My new-to-me 2008 with AT has 85,300 miles. Already changed the timing belt (and good thing, too!) Now I'm scoping in on the tranny. I've read bits and pieces of the answers in several different threads for several different mileages, so I thought I'd start a new thread and collect all the wisdom here!
The oil on the dipstick is brown - about the same color and the engine oil, but not as thick. I have every reason to believe it's been changed at least partially at least once, because this was a rental until sold to the person I bought it from at 43,500 miles. And I don't believe it's been touched since then.
Looking at all the specs, I found Castrol Transmax Import Multi-Vehicle ATF, which (according to their web site) meets Type T-IV, JWS 3309, and GM 9986195 specs. It's available at my local auto parts store for about $20(US) per gallon. My planned usage will be trips in town of 5-ish miles one way (small town); occasionally I may have to take it to work, which is a 35-mile hiway trip. Air temperatures get up over 100F for several months (for a while, they don't go *below* 100 at night!), and the asphalt temps are much higher.
My thought was to do drains from the plug every month or so. I know that's only 2.2 qt in an 8 qt system, and it's not going to get every drop of old stuff out of it. But eventually it should replace most of the fluid, yes? Enough to make a significant difference?
I've heard bad things about a full flush - like pressure pushing O-rings out of place, or shoving little bits of stuff into tiny holes. I've heard there is a way to run the engine and shift through the gears with hoses running into fresh fluid, so you are continually pumping out the old and sucking in the fresh.
Should I just do partials for a while? Just until I replace 8 qt? Or for much longer?
Or should I do a flush of some kind? (I don't trust any shop in town to use spec'ed fluids!)