My 6L90 had a very slight shudder in first gear, part throttle start-up. Over a week it got more noticeable. Yesterday, at three lights in a row, the trans flaired- up on the 2-3 up-shift. Ordering a reman trans tomorrow. Clutch material on the dipstick. Watch out for the internet remans, a lot of bad reviews. Came down to Jasper or GM. Two days to get the GM reman. 215,000 miles, 100,000 miles towing.