Reassembling series 1 Spindle

[bbutcher85710]

My series 1 J-head 1982 model spindle loosened up. The locking washer on the top spindle nut was bent and the nut had backed off a little, and the bottom cap had worked a little loose. The bearings appear to be in good shape. I understand that I may not achieve the ultimate precision and may have to send the spindle in for a rebuild and re-grind. In the meantime can anyone tell me how to tighten the top nut and bottom cap? I know these preload the bearings, but are there torque values, or do I just tighten them tight? I know there is a .003 inch spec on the bottom cap to spindle, but it seems that when the bottom cap is tight the bearings are not preloaded enough, or maybe not at all. Do I need to add a spacer between the cap and the spindle dirt shield to get the proper clearance? My bearings are oiled with spindle oil, not greased.

Bob

[gotis]

It depends,

Most spindles I have worked on have spacers between the upper and lower bearing sets that sets the preload, in that case just tighten them.

Most precision spindle bearings have a marking on the inner and outer ring to mark where the throw is greatest, these markings must line up otherwhise you could permanently destroy the bearings.

[bbutcher85710]

Thanks for the info. My spindle does have equal length spacers between the two lower bearings, and arrows on each bearing. It had the arrows pointing away from each other (top bearing toward top, bottom bearing toward bottom). I assembled it with the arrows aligned with each other and tightened it. I will see how it works, but it feels and sounds good turning by hand, and the runout is a few ten-thousandths. I should have it running later today.