Seat Belt Mechanism Repair?

Hello all, I did a quick search on here, but couldn't find any instructions or assistance on seat belt repair.

On the 74 Gold Duster, The front seat belts are both "finnicky" - The original driver's side box/gears was the worst: It would often lockup when you try to pull out the belt to fasten it. The locking feeling was coming from the black plastic housing with the ratcheting gear near the floor.

My late father in law switched the driver and passenger side, as the pass. side was less problematic.

I would like to fix this correctly.

Does anyone have any information on what wears out internally, as these lockup problems seem to get worse on both sides now.

The trick seems to be pull out with constant pressure, until lockup, then at lockup, release 1/2" to 1" and it will release for some amount of distance, and then keep doing this lock>back 1"> pull>lock> back 1" etc until you get it around you.

Any tips? Is this is rebuild job, lube job or tighten some screw in there?