The ticking noise is caused by the part of the cloth blade inside of the round nose cone. one or more of those blades ends inside catch and chaff with other parts inside making that ticking noise. So to fix it , I gently pried off the nose cone - it takes a bit of effort and force, so try not to gouge the plastic. Try inserting a plastic ruler behind the nose cone and slowly move the nose forward 1mm. That will silence the ticking, The internal part of the cloth blade will stop chaffing and ticking. No need to disassemble the fan at all. - Good luck.