A "full" shift in one direction would be entering 99999999 , which would shift zero approximately 99,999 mm (99 meters) – obviously not practical. The practical full range is limited by your machine's physical travel. Never exceed the hard limit switches.
If you are experiencing vibration or servo alarms during rapid direction changes (like a G01 moving from X to Y), adjusting Parameter 1860 (along with 1620/1622) acts as a "dampener." It forces the axis to hesitate slightly during the transition, eliminating the shock to the ball screw. fanuc parameter 1860 full
If issues arise after setting parameter 1860, consider the following: A "full" shift in one direction would be