Bearings need grease for one reason only, to reduce friction. As long as the lubricant is performing that service well, there should be no need to change it, or add more.

When should you grease bearings?

Using the chart and the formula, the bearing only needs 8 grams of grease every 10,000 hours. If your grease gun delivers around 1.35 grams per stroke, that means the bearing needs 6 strokes every 13 months; you could average it out to a stroke every 8 weeks or so.

Should bearings be greased or oiled?

Oils are the preferred lubricant in open bearing designs or when low torque or high speeds are the priority during bearing operation. “This is due to the relatively lower viscosities as compared to greases. Oil lubrication allows for more efficient movement of the ball through the lubricant, as compared to greases.”