[alloyspec]

Thanks again for all the replies, everyone.
After replacing both X and Y axis thrust bearings the thrust bearings are down to .0005 to.0006 clearance. We updated the backlash values before hooking up the scales.
After plugging the scales back in there was no longer any shudder on the Y axis. We will start using the rigid tap in the next few days to see if that corrected the severe shudder in that mode also.

Alloyspec