My Ra...er...Advice
The new 6-speed auto that comes with the Gen2 V-8 doesn't even have a dipstick "it does not lose fluid". But that's a completely different model trans that uses a fancy new ATF, so I'd expect your 5-speed auto to be serviceable just like any other normal auto trans.
While I'm all for regular ATF + filter changes, I have my doubts about the transmission "flush" that many quick oil change stores are offering these days. IME the #1 cause of auto trans failure (aside from abuse, of course) is filter failure. And IME he #1 cause of ATF filter failure is not dropping the pan and changing the filter often enough.
When I was young and poor, and could only afford used cars, I quickly learned that the typical used car in my price range (~10 year old, usually GM car w/Turbo 350 or similar) would need major transmission repair that I couldn't do in my shop. But I could replace a manual trans clutch, no problem. When those $500 auto trans "bargains" quit shifting, I could get a junkyard trans, and go through the same routine, over and over. I did for a while, and when I noticed that it was rare to find a used auto trans with its filter still intact, I realized that the factory service recommendations were highly optimistic at best.
The manual may say you can go 100,000 miles without dropping the pan, but the reality is that all those bands and clutches that make an AT shift wears away a loq faster than that, especially under heavy use like towing or "spirited driving". All that lost friction material has to go somewhere, and IME what doesn't stick to the bottom of the pan will completely clog the filter by 50,000 miles.
I recommend dropping the pan and cleaning out as much lost friction material as possible at least every 25,000 miles (I'm not alone with that number, BTW). If you do heavy towing or drag racing, cut that to 12,000 miles.
I suppose that power-flushing the transmission can be a Good Thing if it's done by a competent technician using the right equipment, and it's done only after the first cleaning and filter change. But if it's worth doing, it will leave more stuff in the pan and filter, so you'll need to drop the pan a second time to at the very least inspect it to see what came out. And if you're going to the trouble of dropping the pan, you should
always take that opportunity to put in a new filter--it's cheap insurance, and even if the filter looks clean it might be halfway to needing replacement.
So if you start power flushing when the car is new, make sure that the pan is cleaned and the filter is replaced before
and after the flush, and change the ATF and filter every year or two, your auto trans may well last well past the end of the factory warranty period. If you bought yours used, getting to see the results of a power flush can give you a good idea about when your auto trans will fail, so you can start saving up for a rebuilt one when the inevitable happens.
