Upgrade Your CNC
or Hand Operated
Milling Machine

Replace Spindle Bearings
Bridgeport & Bridgeport Type 3-3/8"
Diameter Quill Housing

  1. Remove (CAUTION: Must remove set screw first to avoid damage to end cap & quill housing) set screw in quill housing that locks to threads in end cap. (A)
  2. Unscrew quill housing end cap (NOTE: Some foreign models have left-hand thread end caps). (B)
  3. With quill in UP position and head swung away from table, lock quill with quill lock. With soft mallet or brass hammer tap lightly on upper spline end of spindle shaft. Shaft assembly will slide out bottom of quill housing.
  4. When sending to C&M for removal and replacement, leave shaft assembly assembled. Include (B) End Cap
  5. Bearings are pre-greased and require no further lubrication.
  6. Reverse total procedure to re-install shaft assembly. After insertion of shaft assembly into quill housing, use quill travel over table to press bearings into housing, making sure not to force anything. If hard to push, stop and check alignment and housing for burrs. The assembly should slip together without much force applied.
  7. Upon installing shaft assembly in quill housing, make sure there are no burrs on end tap or at bottom of bearing counterbore. Make sure the end cap seats firmly to the front bearing outer race. (NOTE: There should be a slight gap — .002” to .010”—between end cap and quill housing). On some models it may be necessary to machine off the quill housing end cap to accommodate the four front bearings, maintaining a gap of .002” to .010”
  8. Tighten set screw on quill housing to end cap threads. (NOTE: Do not over tighten; this will distort quill housing.