The title says it all. I don’t want to mix different incompatible grease types if possible. I have a bearing that has started making a noticable noise in the last couple hundred miles.
What kind of grease should I inject in to the alternator and AC compressor bearings in an early 90s Toyota
You don’t inject grease into an alternator/compressor.
If the bearing makes noise, the component is replaced.
I’ll replace the bearings if I have to. There’s no need to replace the whole thing.
If the grease in a sealed bearing is gone… then the bearing is no longer “sealed”. If you add more with a needle, it is even less sealed.
The noise you hear is the bearing failing not the lack of grease and should be replaced. If the bearings in your AC compressor are failing, I 'd suggest rebuilding the entire compressor as the internal components are not far behind the bearing.
I know nothing about grease but prolly 40 years ago I picked up a tube of skill grease for bearings in power saws etc. never seen it sold sense. It seemed like the standard tan stuff with probably some additives. But my chain saws have a very small roller bearing on the shaft of the clutch. It needs to be lubed once a year. The lube comes in a tube with a plunger that is then injected into the bearing and also the spur on the bar. It is a blue lube. About $8 at ace, etc that sell saw accessories by Oregon. I have used it for other critical roller bearings from time to time as a high quality bearing lube.
Bearings are fairly cheap though. It’s getting to them that is hard. When I put new sealed bearings in things like mower spindles, I simply pop off the cover and check to be sure they have grease. Some get missed.
Like I said, I don’t know anything about grease but figure the $8 stuff in a little tube for chain saws is pretty quality stuff.