I have one keyless chuck that has worked pretty good. It just had a tight spot on every turn. I mena when you open or tighten the chuck 1/2 round feels normal and 1/2 round feels tight. First it was slight and I thought it it will wear and even.
But it got worse and even I had an idea how to disassemle it, nevertheless desided to arm myself with youtybe video. Can't hurt:https://youtu.be/h_jQ7-UiWgI
Well. I only took arbor out and the stationary ring at the very end. The ring had been mounted wrong way! It was mounted the pretty side out! Blackening was not that great on the other side.
Cleaned it, greased the face surface and assembled. Works perfect now.