benEzra
Moderator Emeritus
The only problem with silicone greases not designed for metal-on-metal bearings is that those greases do not contain the ingredients (e.g., zinc dithiophosphates) necessary to prevent galling during inevitable metal-to-metal contact. They will reduce friction, but they will not eliminate wear like a quality bearing grease will.
There are undoubtedly excellent silicone-based bearing greases out there (Browning even sold a silicone gun grease for a while), but dielectric grease and grease designed for lubricating/preserving plastic and rubber fittings are probably not as good a choice as a ZDPP-containing oil, much less a good synthetic bearing grease. They may be excellent lubricants, but are arguably not nearly as good at protecting the metal-on-metal interface.
There are undoubtedly excellent silicone-based bearing greases out there (Browning even sold a silicone gun grease for a while), but dielectric grease and grease designed for lubricating/preserving plastic and rubber fittings are probably not as good a choice as a ZDPP-containing oil, much less a good synthetic bearing grease. They may be excellent lubricants, but are arguably not nearly as good at protecting the metal-on-metal interface.