After 400 km bumpy ride two weeks ago, I.

After 400 km bumpy ride two weeks ago, I realized the rear shocks started making a cluncky noise when the car is rolling left to right (not when going up and down). The noise seemed to come from the lefthand side mainly. At the Toyota garage the shock bushes were replaced, but the noise remained. All other possible sources of the noises (stabilizer bar bushes, break pads, etc) were checked and proved to be fine. When driving without the shocks, there is no noise. The shocks themselves seem to be fine (not leaking, one of the shocks was replaced earlier this year, so it is still almost new). Do you have any suggestions as to how to proceed to further diagnose the issue?