Transmission fluid is oil.
White 99, how often do you change your engine oil?
GM maintenance schedule lists lots of things that many people do not follow, and over maintenance their vehicles.
Is it acceptable to maintain your vehicle, to a greater level than the maintenance schedule states?
What is wrong with that?
But you fail to respond to my comments about changing only 1/3 of the fluid, would you change 1/3 of your engine oil?
GM maintenance schedule used to require oil changes based on an oil life index monitor system that allowed some vehicles to go as long as 18,000+ miles before the first oil change. They recalled that system and recalibrated it 3 years later, and the recalibration put a 7,500 max mileage. But, to this day, there are customers who have not had the recall performed.
Are you aware of the 2014 & 2015 maintenance schedule recommendations for transmission, differential fluid, brake fluid, or clutch slave cylinder fluid?
Your statement about fluid other than GM Approved fluid is a contaminant is facetious. There are plenty of fluids out there that far exceed the ASTM testing of GM DEX VI or many other GM fluids. The reason GM makes these statements are totally driven by revenue. GM sells these fluids, and wants customers to buy from GM, and make false accusations about everything but GM. There are inferior fluids on the market, but to claim everything except GM is a contaminant is incorrect.
The GM TSB you refer to does not state your "contaminant" claim posted above. But it does advise against engine flushes. GM issues a very similar bulletin every year or so about aftermarket services. Mainly to defend the sales of their products, trying to lock out the competition.
#04-06-01-029G - (Sep 27, 2012)
Document ID: 2913603
Did you ever think that the transmission fluid exchange costs more than a pan drop, may be because instead of replacing 4 quarts of fluid it may be using 12, 14, or more quarts of fluid. And before you ask why, let me ask you a question, do you wash a coffee cup with 8oz of water?
BTW, not removing the trans pan, minimizes the opportunity for over tightening of the pan bolts resulting in a leak (anyone ever experienced that?).