I had read the threads to flush the trans fluid and use Mobil 1 and if that didn’t work to replace the torque converter, I told my mechanic (I didn’t realize that the class action suit was for the 8 speeds) that GM had made those recommendations. He said when he took the pan off of the transmission it was completely full of metal shavings and beyond repair. Truck has 75,000 so no longer has a warranty.