TRANSMISSION STARTED SHIFTING WEARD CONTACTED DEALERSHIP. THEY STATE THIS UNIT IS NOT UNDER RECALL BUT IT IS AN 6L80 AND IT IS ALL OVER YOU TUBE AND THE INTERNET ABOUT FAILURES THAT START WITH THE PM VALVE AND/OR THE TORQUE CONVERTER HOUSING THAT IS STAMPED BUT MOUNTING BRACKETS ARE WELDED TO IT CAUSING HARDED STEEL TO MEET STAMPED STEEL CAUSING FRICTION AND WEAR THAT POLUTES THE REMAINDER OF THE TRANSMISSION AND CAUSES FAILURE BEFORE 100000 MILES; USUALLY JUST AFTER 50000ISH. WHEN TRANSMISSION FAILS IT CAN CAUSE LOSS OF PROPULSION OR COLLION.