So I've been fighting with the Dubacle of a transmission on my 2011 Silverado. 5FDP has been awesome helping me along the way, but I still have some questions for the group since I can't find anyone else that knows. I recently picked up a tuned Silverado that hit the rev limiter on the 2-3 shift at WOT. After reading the file, it was found that the shift point was messed up and the owner admitted to using a programmer. I had the rev limiter issue and a 2-3 flare at part throttle, and it only did it if I parked somewhere for a while. After pulling a stock tune from another 2011 Silverado LTZ with the same software, I uploaded that and the truck was perfect. The 2-3 flare was still there, but not as bad. I let the TCM relearn and that was the end of it, or so I thought. After time went by the 2-3 flare got worse and the 4-5 shift started flaring too. I pulled the trans and it also had some metal in the pan so I got pissed and bought a low mileage 6L80 from a junkyard from a 2011 GMC. I took it to a shop, and had them completely go through it, with new borg warner frictions, a fresh TCM, and updated seals. I put the trans in, and it literally did the exact same flaring crap my old one did. It slipped the 2-3 and the 4-5 shifts after the trans sits for a while. Doesn't matter how cold or hot it is. I tried tuning it, but for some reason all my controls in VCM stopped working and I couldn't write the TCM, but I could read it no got pissed off again, and dropped it off at the dealer to have them put the whole truck to stock. They updated my ECM and TCM to the latest revision, and I had them do a clutch fill relearn since the trans was rebuilt.

Well, now the damn transmission flares the 4-5 shift and feels like it goes into neutral, grabs the gear, and then goes. I have communication with HP again, and the relearn just makes it worse. My 2- flare is completely gone now. I had my guy go through it again yesterday and he said the trans is perfect!

Am I just loosing my mind or is this trans adapting? What can I do to maybe resolve the communication issues? Every time I try to upload a tune, the trans completely ignores it and does it's own thing. I just don't get it! The truck drives perfect except for the random flaring which is just embarrassing.