Bearing greases compatibility

Hi,

As a general rule, most greases used today are lithium based, though I have a tub of "hi temp disc brake grease" that's an aluminum complex base. Then we add some synthetics that I don't know about at all. Really old time greases were sodium based, and they would react with lithium and bleed excessively. Many years ago I got in the habit of washing everything out and starting fresh if I didn't know exactly what's in there to start, and do that same thing to this day. I don't know what Subaru's using, but I do know they've tried a few different types in their CV joints. Don't know if they've done the same with wheel bearings, but I'd start clean if it were my car. Then you can add grease "safely" as required since you know what's in there. (Some people say NEVER add grease, but I haven't seen a problem when I've done it.)

Best of luck, and Happy New Year!

Rick

Thanks for the reply. I'm asking cause I'm about to replace front axles (96 Legacy, 200,000 kilometers) and just want to replace also the inner bearing grease seal but not touch the bearing itself. I want to put some synth grease behing the seal to keep its lips lubricated (one inner and one outer lip) Was afraid I would mess things up. Maybe I'll just use a minimal amount. Happy New Year to you too!

Hi,

Just checked the tub of Valvoline Syn-Power synthetic out in the garage, and it says nothing about either the base soap, or about mixing with other grease. For the use you're looking at, I don't think I'd worry at all.

Again, best of luck!

Rick