Plain-English Summary
Lubrication separates moving surfaces, reduces friction, carries heat, protects against wear, and can help seal out contamination. Grease, oil, and other lubricants are not interchangeable by guess.
Why It Matters
Lubrication failure is one of the most common causes of mechanical trouble. Too little lubricant can cause heat, wear, seizure, noise, and failure. Too much lubricant can cause heat, seal damage, churning, contamination, product issues, or load problems depending on the application.
Field Rule of Thumb
Clean lubricant in the right place beats more lubricant in the wrong place. Before adding grease or oil, confirm the specified lubricant, compatibility, amount, interval, fitting cleanliness, excess path, and contamination risk.
Walt - Simple Man Takeaway
More lubricant is not always better. The right lubricant, cleanly applied, in the right amount, is the win.
Core Concept
Grease is lubricant held in a thickened carrier and is often used where lubricant must stay in place. Oil flows and can carry heat, lubricate, clean, and circulate through gearboxes, chains, hydraulic systems, oil baths, and circulating systems. Contamination includes water, dust, chips, product, chemicals, abrasive grit, metal particles, wrong lubricant, and degraded lubricant.
Cutting Oil Caution
Some oils are engineered specifically as cutting oils for machining operations such as cutting, drilling, tapping, threading, reaming, and other metal-removal work. Do not introduce cutting oil into a lubrication circuit unless the OEM or lubricant specification explicitly requires it. Cutting oils should be treated as machining/process fluids, not general machine lubricants for bearings, gearboxes, circulating oil systems, hydraulic circuits, pneumatic lubricators, chain oilers, spindle lubrication, way lubrication, or automatic lubrication systems. Wrong oil in the wrong circuit can cause seal damage, varnish, foaming, poor lubrication film, contamination, overheating, component wear, hydraulic malfunction, or failure.
Worked Example
A mounted bearing runs hot after routine greasing. Possible causes include too much grease, wrong grease, incompatible grease, blocked relief path, damaged seal, misalignment, a bearing already failing, or excessive belt tension. The answer is not automatically “add more grease.”
Common Mistakes
- Mixing greases without checking compatibility.
- Overgreasing bearings.
- Using grease as a repair instead of finding the cause.
- Injecting dirt through dirty grease fittings.
- Ignoring low, milky, dark, foamy, burnt-smelling, or contaminated oil.
- Forgetting environment: washdown, heat, dust, product, chemicals, outdoor use, and food-contact requirements.
First Checks / Troubleshooting Flow
- Identify the component and lubricant requirement.
- Check OEM or site lubrication schedule.
- Confirm lubricant type, grade, and compatibility.
- Inspect fitting, port, cap, breather, seal, or reservoir cleanliness.
- Check for leaks, water, dust, product, chips, or chemical contamination.
- Check quantity, level, temperature, noise, vibration, and load.
- Check nearby causes such as alignment, tension, or bearing wear.
- Document what lubricant was added and when.
- Sample oil or escalate when condition is unclear.
Walt says STOP! - Safety First
Make these checks prior to proceeding.
Stop and verify before lubricating, changing oil, or opening systems involving moving equipment, hot oil, hydraulic pressure, pneumatic pressure, gearboxes under load, food or pharmaceutical equipment, chemical exposure, confined spaces, high-speed bearings, automated restart hazards, or environmental spill risk.
Source Notes / References
This page is original Dingfelder practical field guidance. Verify controlled requirements against drawings, OEM documentation, current standards, site procedures, manufacturer guidance, customer requirements, and qualified authority where applicable.