Orac Y axis thrust bearing preload

[huser]

I am trying to fix an Orac that has a large backlash on the Y axis. A dial indicator showed at least 0.010" of lash and it can be seen moving just by grabbing the compound and pushing/pulling it along the Y axis.

After disassembly and wiping away the old grease/oil, and reassembling, the lash is apparently gone but the screw feels a bit tight. No numbers but I was unable to turn it by hand without the timing belt pulley installed. With the pulley installed, I can turn it and move the slide but it feels tight. I applied oil to parts of the thrust assembly prior to reassembly if this makes a difference.

Question is how tight should the thrust bearing on the Y axis be set? I don't seem to have much flexibility there due to the start/castle nut/washer locking
mechanism. I also didn't see anything apparently wrong with the thrust
bearings inside the assembly.