Took apart 4 jaw independent chuck, now it's hard to turn the screws

[cathead]

The pins are probably a press fit and tapered. I made a tool to tap these pins out. They were easy to remove with the tool and just as
easy to reinstall with a tap from the back side.




edit: If the back plate is pushing in the pins, you could pull the pins and take off a few thou from the back of them possibly...

 

[WarrenP]

I loosened up the back plate and tightened it up again and that worked. I have no clue why it did that. The bolts went from the head to the backplate and nothing else. It had nothing to do with the screws or the channels.

I was saying to loosen it then see if the screws move easily and if it got stiff again once you started tightening again.. Sounds like you got it back into position though. If it needs more I would try what Cathead says about shaving a bit off the set pins, sounds like the backplate is putting pressure like he says and pushing against the pins.

 

[Pcmaker]

I tightened up the screws pretty tight and the jaws still move easily. all's well that ends well

 

[TakeDeadAim]

IF the chuck head is not tightened evenly it can cause the chuck to bind a bit. Had it with one of mine, Disassembled stoned off the burs with 400 stone, (it was not bad, just a few high spots) and re-assembled. It was fine on the bench but bound when the backing plate was installed. I loosened it then torqued the bolts in a few steps with a torque wrench, (should have done that initially) and its been fine. Got in the habit of using the torque wrench with all chucks now.