I have a 2010 Traverse with 160,000 miles on it. Transmission has seemed fine its whole life. Lately I have been getting a shudder as you accelerate and hit RPM of 3,000. As soon as it downshifts it goes away. When going up a hill it will do this in any gear you are in at 3,000 RPM. While coasting it does not do this shudder at any RPM (so it is engine and/or Auto trans- not tires out of balance etc). I tried flushing the auto trans fluid 2X but no change. Does anyone know what is going on? Does it need new trans? The car is great otherwise but only worth ~2-3K $ so not sure what the most reasonable approach would be regarding sinking money in. Will the car run like this for 50K miles if I don't do anything or is it about to blow up? I don't know much about this area. thanks for any thoughts.