Dirty lubricant, adhesive wear and poor lubrication: photo guide
Surface finish tells you what was in the oil. Matte and satin means fine abrasives; smeared and torn means sliding; dents mean debris.
Abrasive wear
Dirt or sand in a lubrication system wears bearings. The task is to find the exact source: debris built into the system, cracked housings or hoses, entry through failed seals, contaminated grease. Use magnification to identify the particle type; it leads to the root cause. Fine abrasives in oil usually leave a matte or satin finish on the raceway and rolling elements.
Adhesive wear
With enough cool oil to control heat, the rollers can still stop turning and start sliding. Causes include cage wear or breakage, which lets rollers skew and skid; heavy axial load; starvation. The surface looks torn and smeared.
Improper lubrication method or product
Wrong lubricant or poor application shows as heat colour on the track, scuffing on roller ends and ribs, and wear on cage pockets and guide surfaces.
- Collect oil or grease from the machine before cleaning the bearing.
- Check seals, breathers and grease nipples for entry points.
- Compare cage pocket wear with roller wear; cage wear often starts the skidding.