Hey all, im using a tokina 12-24 and d90 together for my wide shots. recently for no reason, when i turn the zoom ring, with the lens attached to the camera there seems to be a strange screeching sound, as if a car is braking suddenly, and 2 sides are rubbing against each other. not sure what could be the cause. when detached from the body and zoomed on its own, the lens does not have any such sound. need help here so any bros with experience maybe could answer? and like tell me if i need it repaired or cleaned or smth? could something be stuck inside causing resistance?