Brit717

So I have a case into GM to hopefully get some/most of it covered. We originally brought it to a transmission place but as we are hoping to have GM cover a portion of it, towed it to a GM certified dealer. They looked at it this morning, metal shavings in the fluid and tech says that it smelled "burnt up". The dealer quoted $4500 to do it but we are waiting to see if they come back at us with something from GM. What really grinds my gears is that apparently the tech stated that this is caused by mileage. We have babied this truck. Most of the mileage is highway, always up on our oil changes and tire rotations, always doing maintenance as required. We have only towed light loads and never been off roading. For the transmission to fail so quickly with no warning.... with only 107k miles on it, no way!

2015 Gmc Sierra, 106K miles I have searched and I am not getting much luck with this code (P0796) for this type of vehicle. Last weekend, the truck started acting like it had a misfiring cylinder. It was hesitating on acceleration at highway speeds, sputtering a bit, nothing serious but noticeable. No CEL. We thought maybe bad gas or spark plugs as the truck has over 100K on it and we haven't changed them yet. It is on our list to do anyways for the 100K tune up. We put some gas additive in and it semi resolved itself, not happening as often or as bad, with plans to do the sparks and visual inspection of the coil packs and wires this weekend. Yesterday afternoon, driving to the gas station, I go to accelerate after the turn and the RPM shoot through the roof, like the truck is in neutral. I pull over, cant get the truck to work properly. Shut it off and wait about 5-10 min, start up again and it finally works and I'm able to finish pulling into the gas station. At this point the CEL does come on and its the P0796 code. Bring it straight to my mechanic and he states that the Tranny is toast. The fluid level was fine, but the fluid was more of a brownish red instead of the redish-orange. He explained that inside of the transmission, something basically deteriorated and caused a whole bunch of damage inside. He is quoting me $3700 for complete install of a crate transmission with a 3yr warranty on it. Dealership we bought the truck from is quoting $5500. So I guess, has anyone else had this issue? Is there any TSB or recalls for this issue, and if not, what could be my best course of action? I feel like just over 100k miles is really early for a transmission to break down so quickly. Thanks!