The #1 bad thing you hear about flushes is because people who already had transmission problems went and had a flush done and their transmission broke afterward. The key phrase was "people who already had transmission problems." They think that the problems are caused by the fluid so they go change it. If you wait till the fluid is shot badly enough to cause the problems, it's already too late.I've been reading into changing the ATF in my cruze lately and have decided I want to try to change it every 40k or so. However I'm not mechanically savvy whatsoever and I don't think I should attempt this myself. I hear a lot of bad things about flushes and it seems to be what all places are telling me they will ONLY do and to do it or nothing at all. My main question is should I have them flush it at a local auto shop (about $140 for Dex 6). Or not trust it and have the dealer flush it, or just find a dealer that will drain and fill?
Get it flushed. If you can afford it and know a shop that doesn't mind you bringing your own fluid, run AMSOIL Signature Series ATF as it shifts smoother and is guaranteed for 2x of GM's severe service interval of 45k miles.