Yep, I was gonna convert mine to a Harken or Shaefer sheave with bearing but never got around to it.
I just grease 'em every now and then.

Too bad the mfr's use a cheap weld-on sheave....wouldn't cost much more for a bearing sheave or even a sheave with an Oilite bushing.
I completely wore out my first jam cleat/sheave combo and Willie was good enough to send another....no charge.
That's the one that really needs a bearing.