The new fluid stopped the "rumble strip" shudder. It still has another condition that I would call a shudder. It still has delayed engagement, stumbling, etc.
I have a 2015 with the dreaded 8L90-E GM slush box. It's a piece of junk that only gets worse with age. Is there a way to actually fix this thing? I wouldn't mind upgrading some of the internal parts if I could make function like it should. I don't want to put stock parts back in. They didn't do so well the first time. What have others done?