Hi
Sounds like the spacer and shims inside the spindle housing between the two bearings is too short. Take out one of the bearings and add one or two shims either GT00539 (5 thou) or GT00541 (10 thou) to lengthen the spacer so the center of the bearing rests on each end of the spacer when pressed back together. When the nut is tightened, the disc and spindle should spin freely.