Have you miked the bearing journals on the spindle and how easy did the bearing cones remove from the spindle? I'd be curious to know what you found. At this point I have not removed the spindle or bearings on the 8k. I decided early on to flush out the bearings with oil and see what happened. About a quart of oil was used, and the metal flakes comming out in the drain oil reduced to undetectable. The screeching noises I heard from the bearings have not reocurred since flushing. The heat produced during run-in of the bearings was more than I expected, and I contacted SB and was sent their bearing prelaod procedure. I did reduce the preload until the heat produced on the headstock is just warm to the touch after about 15 mins of running at 1000 rpm. I've had problem bearings before and most of the time the problem has traced to bearing preload. Roller cages on bearings can drag and cause noises until they seat properly hopefully before they wear out. I wish you good luck on the new spindle.