Many people assume that if two greases look similar or share the same NLGI grade, they can be mixed safely. That assumption causes real maintenance problems. Grease compatibility depends on thickener type, base fluid, and the resulting mixed properties after blending. General compatibility charts are only guides, and testing is often still necessary.
When incompatible greases are mixed, they may soften, harden, bleed oil, or lose lubricating consistency. Incompatible mixtures can show excessive hardening, excessive softening, or oil separation — especially under temperature and shear. That can lead to leakage, starvation, or rapid component failure.
The safer approach when switching products is to purge the old grease thoroughly or clean the system where practical. Compatibility should be checked using thickener type, base oil, application conditions, and supplier guidance. Appearance is not a valid compatibility test.
Can I mix two greases just because both are lithium-based or the same colour?
Not safely as a rule. Compatibility depends on more than colour or broad thickener family, and testing may still be needed.
Planning to change grease grades or brands? Banesto can help you assess grease compatibility before you risk bearing problems.
Talk to Our Team →