Recently had 4T65E transmission replaced with remanufactured one.
Noticed that on wide open throttle, when it shifts from 2nd to 3rd, the transmission makes a chattering sound. Very similar sound that a drill makes when it has reached the torque setting of an adjustable clutch.
Took it back to transmission shop, and they didnt seem to experience the same issue during test drive. They did see an issue with the amount of play/flex of my motor mounts. I have since replaced the top mounts above the radiator attached to the dog-bones.
Have since put on about 3000 miles. Fluid levels are good. Shifts nicely otherwise.
But, What is the chattering sound?