ForensicEngineer

These gm 6-speeds eat torque converters and often ruin the transmission in the process. Our 2017 suburban with the 6 speed is having the same problem at only 93k miles! Our 2009 tahoe with the same transmission also had the same torque converter failure at 107k miles. Neither was used for any significant towing. GM really screwed the pooch with the tuning on these transmissions; they burn up the torque converters with the constant locking and unlocking of the clutch and partially engaging... and getting tons of wear in an attempt to get a slightly smoother shift and a tiny fraction of a mpg better. They have known a long time they have a problem with these torque converters getting burned up, but in 10 years they have only made the problem worse with more TCC cycling. The 2017 burban unlocks the torque converter every time the thing goes into V4 mode, so every little change in engine load on the highway like a small hill results in more torque converter cycling... Hate to say it but this is likely the last time I will purchase another GM truck/suv. Sick and tired of expensive, premature transmission failures. I work in an industry we all have full size trucks and we rack up miles quickly on the road. The Nissans, Fords, and Toyotas are all getting 250k+ miles without major work on their drive trains, but ALL of our Chevrolet and GMC guys are all having major transmission problems either from day 1 (8-speed) or the torque converter burning up and causing the rest of the transmission to be ruined in the process (6-speed). As a mechanical engineer myself, this is simply a disgrace of engineering and quality control, and makes our group of engineers still driving the GM branded trucks look, quite frankly, stupid. I thought (hoped) GM had grown out of their old ways... I'm not so sure anymore.