Stama 25-60-40-M Even sealed bearings can become contaminated
Stama 25-60-40-M, 8600 RPM, grease lubrication, coupling driven
This spindle is used in the manufacture of automotive braking components. The spindle bearings felt notchy when rotated by hand in assembly incoming, and upon disassembly the spindle interior was found to be loaded with a dry, black particulate. Despite the fact that there were sealed bearings in the front and rear of the spindle, the remaining grease in both pairs was severely degraded from contamination with these particles, and all four bearings felt significantly worn when rotated.
Our customer was fortunate in that we did not observe any significant dimensional deviations of the manual HSK63 tooling taper, bearing journals and shoulders, or housing bores. We rebuilt the spindle with all new bearings, o-rings and assembly screws. We finished this straight rebuild with our final test run, break-in and final QC.