Thanks man! And yes, correct! The 09 didn't have the AFM, but the transmission had no problem crapping out multiple times. Side story, I also have an 07 Silverado Max (NBS) WITH AFM, and the lifters had issues back in 2019, about 50k miles ago (this is before I knew about AFM/DOD Delete, so we had it fixed but that V4 mode would make the engine shudder and rumble, it was never the same after that.) Of course, that shuddery, low speeds V4 mode nonsense went away when I got the AFM Disabler, and my truck stopped throwing codes intermittently, as well.
The transmission on my Silverado started hesitating when shifting, I think 2nd to 3rd, and it would shudder a bit when running at higher highway speeds about 2 years ago, at 170k, and I took him in right away to have it rebuilt. The transmission shop guy was amazing, and walked me through the whole process, and he was so happy that I had the AFM Disabler plugged in, saying it would help save my tranny down the road if I had that plugged in. That the transmissions aren't designed to handle the AFM engines or something along those lines. Excuse my lack of proper terminology.
When I got my 14 Denali, I immediately bought an AFM disabler for her, because I had remembered what he said. So I need to keep an eye out for what you said. I haven't had any issues yet, but once in a while something will happen, a slight shudder, or a harder than usual shift, maybe once a week or so. And I panic thinking, oh god here we go. So I'm just being extra careful and alert, knowing that it could come at any day.
I had the transmission serviced (not flushed) about 4k miles ago. Do you think it's worth finding a shop who can do what you said? Replacing the torque converter? Any ballpark of what I should expect to pay? Of course I'm not in the same area as the previously aforementioned tranny shop, so, I'd have to find someone else to do the work. In the Metro Detroit area.
Sorry for the long post. I tend to spill way too much info.