I've attached a PDF for you bricKheads who would like to explore this further.
Here's the home link on general lubrication data. http://tinyurl.com/motobrickgrease
Greases of different brand names is not the issue. The issue is that greases
use different compounds as thickeners, and the different thickeners are not
When greases made from different thickeners are mixed, the mixture may be
poorer in service performance or physical properties than either of the
component products. The lessening in performance capability is called
incompatibility. It may show up in any of several areas, such as (1) lower heat
resistance; (2) change in consistency, usually softening; or (3) decrease in
shear stability. Mixtures which show none of these changes are considered
Incompatibility is not always caused by the thickener, since each of the greases
in the mixture is a complete package--thickener, fluid, and additives.
Sometimes the thickener of one grease is incompatible with the fluid or the
additives present in the second formulation. If the mixture proves to be
significantly softer, less shear-stable, or less heat-resistant than the original
grease, the mixture must be deemed incompatible.
Incompatibility is best determined in service or in service-related tests; it is not
predictable. Certain thickener combinations often have been found
unsatisfactory and are generally so recognized. These would include lithium and
sodium greases and organo-clay and most soap greases. Tests should be run
on the specific greases of interest.
The problem arises most when greases are mixed while the bearing is in service. If there is any concern about potential
compatibility, thoroughly clean the bearing, race and other areas in the greased areas (including the fittings) before switching to
another grease type.