2013 2.4. Bulletin on black transmission fluid

[Fitter30]

After finding the trans fluid black at 50 k I've changed it 1 gallon at a time 10 times to clean it up a. It's now back to red. Just told that there is a bulletin on it and the black is from some coating that interal had on them.

 

[Gonzo 2.4]

After finding the trans fluid black at 50 k I've changed it 1 gallon at a time 10 times to clean it up a. It's now back to red. Just told that there is a bulletin on it and the black is from some coating that interal had on them.

I learned the same thing on my 2016 Sierra 8L90E, 40k it was dark, drained a couple times in a short time, then about 3 more time since 150k its still perfect. When asking about the dark fluid at 40k a tech chimed in and said the same.