I HAVE A 2015 GMC SLT CREW CAB, 4X4 WITH 6.2L, 8 SPD. I HAD THE SAME VIBRATION IN MY TRUCK. I HAVE 30,000 MILES ON IT, AND HAD THE VIBRATION ON AND OFF FOR THE LAST SIX MONTHS. LAST WEEK I HAD IT SERVICED AT THE DEALER WHERE I BOUGHT IT AND MENTIONED IT TO THE SERVICE MANAGER. THEY HAD ONE LIKE MINE THE MONTH BEFORE AND WHEN THEY FINISHED MY SERVICE THE MANAGER CAME OUT AND TOLD ME MY TRUCK WAS READY AND THAT HE ORDERED THE TORQUE CONVERTER AND OTHER MISC PARTS AND WOULD CALL WHEN IN. I TOOK IT IN TUESDATY 2/21/17 AND THEY CALLED THIS AFTERNOON, TRUCK WAS READY. I PICKED IT UP AND WHERE I WAS ALWAYS HAVING THE VIBRATION, IT WAS GONE. IT IS DRIVING LIKE IT DID WHEN IT WAS NEW, NO VIBRATION. ON MY REPAIR ORDER IT HAD BAD TORQUE CONVERTER BULLETIN #PIP5337.
HOPE THIS HELPS
I HAVE DELT WITH THIS DEALER FOR THE LAST TEN YEARS AND THEY HAVE NEVER GIVEN ME THE RUN AROUND.