This info may be helpful to some so I think I'll pass it along.. There are 3 bearings inside the gear case, you can order them from W&H, (who has just been purchased by the Original Saw Company, 10/1/2020). Or you can out source them yourself. There are (2) P-125 bearings and (1) P-126 bearing.
P-125 is a 1601ZZ bearing
P-126 is a 1602ZZ bearing
I don't know more yet about any of the gears, but I hope this helps someone out there to purchase at a fair price and a quick turnaround.