We bought a 2015 Tahoe this summer with 85,000 on it, at around 90,000 we started to feel vibration at 35-50-55-80mph. At our free oil change time i had them look it over and the dealer told me it might be a balance issue with the tires. Well a week later it seemed like it got worse. It has the 5.3 6 speed trans. I read where the 8 speed is the one that has issues. The dealer said it is deff the transmission and it will be covered by my warrenty. They replaced the TCC the pump which was scored and there was metal in the fluid and it was dirty. They also replaced some solenoids and some kits. We get it back and within 2 weeks its still doing it. I took it back to the dealer and asked if they flushed it since its still doing it and they said that is only with the 8 speed. They told me it usually takes 1000 miles for the new trans fluid they added to work its way through the system. I looked at my paper from the last service and it was over 1000 miles since they fixed it. Thew dealer says drive it over the weekend and see if its goes away, if not bring it in. What else could be causing this to still shudder? Would it be the Torque converter? The repair labor wise was 17hrs!
