Northland Tool Blog
Topper Spindle Rebuild

Topper Spindle Rebuild

Possible cause of failure:
Bearing failure from contamination in the front and rear.
Rear of spindle covered with dried coolant.
Drawbar and bellevilles are extremely rusted, rotary union may have been leaking if being used.
Taper is very rusted and pitted, sitting well below gauge line and has 80 microns run out.
Spindle nose is equipped with an air purge, but the fitting hole is plugged and not being used.
Rear shaft roller journal is 0/-3 (iso is +2/+9) with this bearing set up it should be around +3.5.
Drive pulley teeth are showing a lot of wear.

Recommended action:
Clean, inspect overall dimensions.
Grind, chrome plate and finish grind the shaft taper and rear shaft journal.
Replace bearings, bellevilles, o-rings, screws, crush rings, gripper balls, and drive pulley
Adjust preload, balance, assemble and break in. Final quality control inspection.
Install air purge when installing the spindle