Case Study: Using Oil Analysis to Diagnose the Root Cause of an Overheated Gearbox

Evan Zabawski, Senior Technical Advisor, Eurofins TestOil


Far too often an oil change is performed on an asset when poor oil analysis results reveal high levels of wear, yet this does not truly address the root cause of the wear. This presentation will use an example of a bearing with high wear debris alarms but no alarms on the lubricant properties to show how to detect a common issue frequently found in bearing applications. Through guidance on proper interpretation techniques, you will discover how to interpret an oil analysis report to determine the causes of the alarmed data, identify commonly misdiagnosed root causes and decide on the best course of action.


  • Understand some lubrication basics as they relate to oil films.
  • Determine the Causes of Alarmed Data.
  • Identify commonly misdiagnosed root causes and decide on the best course of action.


Evan is a Certified Lubrication Specialist with extensive experience training tradesmen and professionals in a variety of fields including: lubrication fundamentals, contamination control, condition monitoring, RCM/FMEA and used oil analysis.

He has been a member of STLE for over 20 years, serving as Chair of the Alberta Section for 8 years, and also as an instructor of the Condition Monitoring course at STLE Annual Meetings. Evan is currently Editor of TLT Magazine, and has served as the Editor for The STLE Alberta Section’s Basic Handbook of Lubrication – Third Edition, and contributed as one of the editors for STLE/CRC’s Handbook of Lubrication and Tribology, Volume II: Theory and Design, Second Edition.

He has published several technical papers as well as over 130 articles related to lubrication, friction or wear.