Technology Digests / Reconditioned Bearing Performance: Phase 3

TD25-005

June 25, 2025
Authors
  • Matt Wenger
  • Brian Lindeman
  • Anish Poudel
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Key Findings

  • Compared to Phase 2, Phase 3 of reconditioned bearing performance testing showed great improvement in the ability of NDE inspection to accurately predict whether bearing cups would spall early in their service life.
  • The presence or absence of ECA scan indications within a cup raceway accurately predicted the outcome of service life testing 87 percent of the time.
  • Multiple large-batch inspections of reconditioned bearing cups showed a 3–4 percent ECA indication rate.
  • The bearing cups that spalled during service life testing did so quickly. Future rig testing will be shortened from 240,000 miles to 120,000 miles, allowing for increased research capacity.

Reconditioned Bearing Performance: Phase 3

MxV Rail continues to study the service life of reconditioned bearings and evaluate a nondestructive evaluation (NDE) technology to improve the bearing reconditioning inspection process. In the North American railroad industry, any time bearings are removed from an axle, they must be reconditioned before re-use. Based on component tracking data gathered through 2024, approximately 65 percent of the bearings in North American service have been reconditioned at least once in their lifetime.1 The bearing reconditioning process includes disassembly, inspection, repair of non-condemnable defects (if needed), and re-assembly of the bearing with new seals and grease.  As part of the Association of American Railroads’ (AAR) Strategic Research Initiatives (SRI) program, MxV Rail has performed three unique phases of reconditioned bearing performance testing. Phase 1 examined the operating temperature and vibration levels of various bearings immediately before and after the repair of raceway spalls.2 Phase 2 used flexible eddy current array (ECA)…