Wish I could help more. All I know is mine does kinda clunk when hitting the 5 mph mark during braking. This is apparently normal and sometimes is not as noticeable as others. Seems like if I slow down more gradually it tends not to happen, and it does tend to happen more during harder, less gradual stops. I guess it is the TOD disengaging because I know it engages at 5 mph, too. Thing about that is I never hear it engage during acceleration, only the apparent sound of disengaging during deceleration.