2013 GMC Sierra Powertrain & Transmission Problems

INITIALLY I FELT THE PROBLEM AS A SLIGHT "MISSING" IN THE ENGINE UNDER VERY LIGHT ACCELERATION BETWEEN 40 MPH AND 55MPH AND MORE PRONOUNCED UNDER CONSTANT THROTTLE GOING UP GRADES ON THE HIGHWAY AT A SPEED OF ~55 MPH (1400-1500 RPM). THE VEHICLE SEEMED TO BE "LUGGING", AND THEN THE RPM WOULD INCREASE BY ~20% IMMEDIATELY FOR A SHORT DISTANCE AND THEN DROP BACK (ALL AT CONSTANT THROTTLE) TO 1400-1500 RPM. WHEN DRIVING ON THE HIGHWAY IN CRUISE CONTROL AT 60 MPH AND GOING UP A GRADE, THE VEHICLE WOULD SHOW SIGNS OF "STRAINING" AND IMMEDIATELY INCREASE IN THE RPM BY ABOUT 20% WITH AN ATTENDANT ACCELERATION. THEN THE RPM WOULD INCREASE INSTANTLY BY ABOUT 1000 RPM AND THE VEHICLE ACCELERATES RAPIDLY UNTIL I ENGAGE THE BRAKES. MY DEALER OBSERVED THE SAME CHARACTERISTICS AND DETERMINED THAT IT WAS A TORQUE CONVERTER PROBLEM AND ON 07/25/2014 THEY INSTALLED A NEW TORQUE CONVERTER, WHICH PROVED TO HAVE NO EFFECT ON THE PROBLEM. I WAS INFORMED BY THE SERVICE MANAGER THAT GMC TECHNICAL SERVICES INFORMED HIM OF A SERVICE BULLETIN (#PIP4681D: RANDOM BUMP CHUGGLE OR FISHBITE SENSATION WHILE CRUISING AT APPROXIMATELY 1,300 RPM- OCTOBER 31, 2013) THAT ADDRESSED THE PROBLEM, AND FURTHERMORE NO FURTHER CORRECTIVE ACTION COULD BE TAKEN. ON AUGUST 6,,2014 I WAS DRIVING AT CONSTANT SPEED OF 60 MPH ON A MAJOR HIGHWAY IN "CRUISE CONTROL" AND MODERATE TRAFFIC. WHILE GOING UP A LONG GRADE FOLLOWING ANOTHER VEHICLE AT A SAFE SPEED, MY VEHICLE IMMEDIATELY JUMPED ~400 RPM AND THEN ABRUPTLY CHANGED TO A LOWER GEAR AND ACCELERATED SUDDENLY PUTTING ME AT RISK OF COLLIDING WITH THE VEHICLE AHEAD OF ME. I QUICKLY APPLIED BRAKES AND WAS ABLE TO AVOID AN ACCIDENT. I IMMEDIATELY CONTACTED GMC CUSTOMER SERVICES WHO OPENED A CASE NUMBER ([XXX]) AND ASSIGNED A REP. TO MY CASE. I HAVE SUBSEQUENTLY BEEN INFORMED OF THE GMC COMPANY LINE--"THE VEHICLE IS OPERATING AS DESIGNED", "LIVE WITH IT"!!! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR

TL* THE CONTACT OWNS A 2013 GMC SIERRA 1500. WHILE DRIVING 40 MPH, THE CONTACT STATED THAT THE VEHICLE WOULD JERK AND SHIFT IN BETWEEN GEARS. THE VEHICLE WAS TAKEN TO THE DEALER BUT WAS NOT REPAIRED NOR WAS THE FAILURE DIAGNOSED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 200.

HELLO, THE DATE AND MILEAGE ABOVE IS NOT ACTUAL DATE OF FIRST INCIDENT, BUT IS THE FIRST TIME I TOOK IT IN FOR THE FIRST OIL CHANGE AND VEHICLE INSPECTION WHICH ALSO WAS THE FIRST TIME I COMPLAINED TO THE DEALERSHIP ABOUT THE ISSUE. MY TRANSMISSION SLIPS BETWEEN 2ND AND 3RD GEAR AT LEAST 4 TIMES A MONTH. THE DEALER TOLD ME THAT IF I CANT PROVE IT OR IF IT DOESN'T DO IT WHEN THEY DRIVE IT THEN THEY CANT PERFORM A DIAGNOSTIC TEST TO FIX THE PROBLEM. THE SELLER WHO SOLD ME THE VEHICLE CALLED ME TWICE TO SEE HOW IM ENJOYING MY TRUCK AND I COMPLAINED TO HIM BOTH TIMES ABOUT THE ISSUE AND HE TOLD ME THE SAME THING ABOUT MY ISSUE. I EVEN LEFT VOICEMAILS TO HIM ABOUT IT AND HE NEVER RETURNED MY CALLS UNTIL I MADE A YEAR (3/16/14) OWNING MY TRUCK AND CLAIMS HE DON'T REMEMBER ME TELLING HIM THIS THE FIRST TIME. IM A STRONG GM FAN BUT I FEEL IM NOT BEING HELPED WITH MY ISSUE AND ITS ANNOYING THAT I HAVE TO DRIVE MY TRUCK CAUTIOUS GUESSING WILL IT SLIP THIS TIME OR WILL IT SLIP NEXT TIME? IF ITS PROFESSIONAL GRADE THEN WHY AM I HAVING THIS PROBLEM? I USE MY TRUCK FOR FAMILY VACATIONS AND I KNOW ANYONE WITH THE SAME PROBLEM WOULD NOT DRIVE THIS TRUCK FAR AWAY FROM HOME WITH THIS ISSUE. IT DOES IT WHEN IT WANTS TO BUT ITS JUST FUNNY HOW IM TRYING TO FIGURE OUT WHEN IT WILL DO IT AGAIN. I GET ALL THESE EMAILS ASKING ME TO RATE THE DEALERSHIP 5 STARS AND TO RATE THE TRUCK BUT I CANT EVEN GET MY TRUCK CHECKED OUT. THEN THEY TELL ME THEY WONT GIVE ME A RENTAL WHICH I WOULD NEED ANOTHER TRUCK AS A RENTAL. THIS IS SAD I SPEND 30 GRAND ON A TRUCK I CANT GET WORKED ON UNLESS I HAVE PROOF. *TR

THE TRANSMISSION ON THIS VEHICLE SLIPS SOMETIMES BETWEEN 2ND AND 3RD GEAR AND ALSO WHEN PARKED ON A HILL AND PUT INTO DRIVE THE TRANSMISSION SHIFTS LATE INTO 1ST GEAR. *TR