Tension Head Gripper Issue

I’m currently in the process of restoring an old stringing machine I bought and recently took apart the tension head gripper to give it a good clean. My issue now is that it won’t seem to glide like it used to and I’m struggling to figure out why.

The diamond grip plates have two channels with 7 ball bearings each, though I didn’t count how they were distributed when I first took it apart.

A friend suggested I need more than WD-40 as lubricant.

Video for reference https://youtube.com/shorts/RCWagb9yIeM?feature=share

Any thoughts or suggestions are appreciated!