72 eaton rear axle leak

[scotts 72]

Have replaced both the bearing and the race and tryed two new axle seals and the stupid thing still starts ti leak in a few days time. It does appear to have some grooves on the surface where the bearing/seal ride on.Almost looks like a bearing seized on the axle and spun some grooves on the spindle.My question is thisoes the spindle bolt on to the axle housing,Or is it welded on.????? Iam new to this game, and hope someone can point me in the right direction.If it does bolt on ,where can a replacement be found? Am I going to have to start looking for another rear-end HELP!