Bobschatter

So in Dec. 2018, with barely 20,000 miles on the truck, I got the dreaded (torque converter) shudder. I had the "3-flush" procedure with the Dex 6 . It did resolve the shudder at the time but annoyed that a few months later the TSB about a new Mobile 1 LV was not sent forwarded to me. Fast forward to Dec. 15th and, yep, full on return of the rumble strip shudder. Of course, I just saw the Service Bulletin 21-NA-199, dated Dec. 2021, that emphatically states the194 deg. thermal bypass valve should be replaced with a new 158 deg. version (Part #86774933). The bulletin states "Some customers may comment on one or more of the following conditions-blah, blah, blah...slip, vibration SHUDDER." Why would GM not inform Owners? Obviously they felt the transmission fluid was running too hot and contributing to mechanical failures. Since I live in South Florida I would have replaced it myself to maybe prevent the TC issue and save wear on my tranny. Well, I took it in to the dealer who said that since the 3-flush procedure did not resolve the issue that the TC has likely failed and needs to be replaced at a cost of $2,996 as the 5 year powertrain warranty expired 5/16/21. The truck only has 35,000 miles on the odometer. Comments? Suggestions? Have the system flushed again and see what gives? Contact GM Customer Service and see if they will fix it? A bit disappointing as I had also bought new a 2012 Silverado 1500 LT CC that I traded in for the current truck and I still own the 2003 Corvette Convertible that I bought new as well.