How should lubricant evidence be preserved when a failed bearing is removed?

LILY Bearing | 2026-10-28

Best answer

Sampling is part of preserving the failure evidence

JTEKT advises recording the bearing condition and collecting lubricant for examination before cleaning.

Once lubricant from the bearing is mixed with cleaning liquid or general waste, information about its original condition and location can be lost. The sample should therefore remain connected to the exact specimen and collection circumstances. Its appearance can be recorded without turning it into an analysis result. Follow the applicable laboratory or examination instructions for the container and handling rather than improvising a universal sampling method. The goal is representative, traceable evidence that can support investigation of lubrication or contamination conditions.

Label the context as carefully as the container

Include the machine and bearing position, collection date, lubricant identity if known, exact location, machine state and any contamination introduced during collection.

Record whether the sample represents residual material inside the bearing, nearby housing lubricant or a system drain. Keep these samples separate where the examination requires it. Do not present a sample taken after cleaning as though it preserved the original bearing lubricant. If identity or collection conditions are uncertain, report those limitations. Linking the specimen, sample and photographs makes it possible for the examiner to evaluate the evidence without reconstructing an undocumented collection event from an unlabelled container.