I use the G800SDX rotator and GS-065 Bearin
About the service of Yaesu parts I can be clear, it SUCKS, questions not answered, parts very expensive or can not be ordered.
Some HAM shops even strip new rotators for parts.
When I bought my G800sdx second hand the bearings were in very bad condition although the rotator was only 5 years old, it seemed that yaesu used very cheap grease because there was nothing left of it.
Trying to order 98 new ball bearings is impossible (not even thru yaesu benelux).
For those who need ball bearings here is what you should look for: ball bearing 3/8" (9.525mm) 65 rockwell 65/35(steel/nickel) it should set you back about 35 euro.
If you use The rotator in a tower (like I do) it is a good idea to use some dampening rubbers between the rotator and tower and Thrust bearing and tower, this solves the misalignment and noise coming from the rotator