Can two bearing greases be mixed just because both are lithium-based?

LILY Bearing | 2026-10-28

Best answer

A broad thickener label is not a compatibility result

JTEKT warns that mixing different greases changes their properties and that even greases with the same thickener can interact adversely because of additives or other differences.

The words “lithium grease” therefore do not establish that two products can safely be mixed in a bearing. Nor does matching colour or consistency provide that evidence. Identify the exact old and new products, including their technical data and any known mixed-service history. A compatibility claim should come from an appropriate manufacturer assessment or applicable testing, not from similarity of labels. Keep the question of mixing separate from whether each grease is suitable when used alone.

JTEKT: Lubricant

Make a changeover inquiry specific enough to answer

Give the lubricant supplier and equipment owner the two full product names, expected temperature and load, lubrication method and the amount of old grease likely to remain.

Ask for the approved changeover method and its verification requirements. A statement that the replacement has the same NLGI grade does not answer these questions. If the bearing cannot be fully cleaned under the approved repair method, state that constraint rather than pretending the new grease will enter an empty system. Record the resulting instructions and product identities on the job sheet. This creates a checkable transition plan without prescribing a generic purge or cleaning procedure for every assembly.