There is so much truth to this statement, as I just changed my fluid yesterday.Thanks for reporting back. To clarify something though, the fluid was dark because of the rust inhibitor that GM put inside the transmission, which is wearing off into the oil and causing massive amounts of shifting issues. That is the biggest reason I recommend people change their transmission fluid no later than 20k miles with these transmissions. Rumor is that GM stopped using that rust inhibitor in their transmissions, but we have yet to determine that based on transmission shifting. This is an unusual case where the color of the fluid does not indicate that it is burned, but rather contaminated.
With the car on the lift, we pulled the drain plug and collected a sample. What was removed looked exactly like as described. "Normal" trans fluid should resemble something of cranberry juice. What I removed from my trans barely had any red tint to it at all. The fluid did not smell burnt, just looked terrible.
2012 Cruze LTZ 6A
17,975 mi @ time of change
Poor shifting noted for at least 5000 miles.
Extremely poor shifting noticed for the last ~2000 miles, especially when car is cold. Significant delays noted when shifting between park/reverse/drive, followed by a jerk into gear.
Car has experienced LOTS of stop and go driving in daily commuting.
Car has been tuned for just shy of 10k, but given how little I'm able to use the performance mode, that has little to no effect.
Ordered the Amsoil fuel efficiency fluid as prescribed, hoping to eliminate these issues and prolong the life of the trans.
Attempted to find a local place to flush the trans. They're all pussies and afraid to mess with it under warranty. GM dealers won't touch it since I didn't want GM fluid. Found one place that may be able to, but they are booked up, and I never got to tell them the kind of car. I received feedback ranging from "we need 16 quarts to fill our non-adjustable machine to ensure no air bubbles" to verbal abuse such as "How dare you mess with it, take it back to the GM dealer and have them fix it under warranty because it should not be having problems at 17k. If they still refuse, drive it until it breaks".
Let me just say this, I refuse to drive the car in such a state, waiting for it to break. We're in this relationship for the long haul, and I don't want to replace the trans at 101k because of idiots spewing word sperm now.
Long story short, found a couple guys I know with a heated garage with a lift. One is a tech at a Mercedes dealer, the other is at a Deere dealer, and both work on lots of cars with a hobby of off road jeeping and trucks. Went out there yesterday intending to pull a cooler line off and pump it through.
Once we got it in there, the guys soon determined that the cooler lines are a press fit and can't be removed unless with a utility knife.
At that point, one of them contacted a buddy from work who has access to AllData. For those who don't know, that's a database for service shops to access service manuals for cars that they don't have actual manuals for. In other words, an (expensive) subscription enables independent shops to do things on just about any car. AllData's database is fed directly from OEM service and repair manuals, so the information is legit. While waiting for the buddy to call back (he was on the road), they googled on their phone. The service procedure explained here is nearly verbatim from AllData:
So we followed that procedure, twice. Drained the factory fill, refilled, brought the new fluid up to temp. Drained that out, then refilled again most of the way, following the idle/gear change procedure described each time. Waited to bring that new fluid up to temp before topping off for the final adjustment with the level plug.
Took it for a spin and I could tell a difference. Not significant, but enough. Certain gear changes that had been harsher are now much smoother. 3-4 and 5-6 especially.
However, the big difference came this morning. The cold operation of this fluid is significantly improved. The car used to really lag before when trying to shift as I'd leave for work. Now it acts just like it was warm, save for the torque converter lockup.
I may not have every last bit of the old fluid out, but I couldn't afford to chase a losing battle for finding a flush place and have to take more time off of work. So much is replaced now that the improvement is significant enough.
All in all, while I do highly recommend the Amsoil for being a far superior fluid, just getting the fluid changed is the important part, even with just fresh GM fluid (a GM fluid flush at the dealer is around $160). You'll be happy you did.