Have a feel at the joints at each end of the rod that connects the strut to the anti roll bar. I am not sure of it's actual name but it is about 14 inches long and fits almost vertically behind the strut. On each end is a ball joint and they wear out. When the car is jacked up the tension from the anti roll bar bar hides the failure, but if you have the car on a ramp so the wheels are in the normal position the wear can be seen. Mine clunked as the car was bounced gently. It's an easy and cheap repair too.