I brought my 2011 Silverado LT 5.3 6spd auto in for a 30k maintenance today. Its at 33k so Im a little overdue but I was waiting for oil change time and Ive been having a surging issue with the trans once in a while when slowing down that I wanted the dealer to look at. I did the intake cleaning when I swapped in a new intake last month so the only services I needed were oil change, coolant flush, and trans flush. The coolant flush and oil change were completed with no problems. When they got to the trans flush the tech dropped the pan and found internal transmission parts laying in the pan, 2 short bolts, 1 nut, 3 washers, and some unidentifiable broken metal chunks, along with a palm full of metal shavings. The scarey part was other than the surging issue once in a while I had no noise or other trans issues. Fortunately before the service advisor managed to talk to me he had determined they would cover it under warranty and he located a replacement trans. I should have my truck back Monday afternoon with a new replacement GM trans.