is a sealed bearing I used to repair an MTD spindle. I didn't worry about greasing, I've got a lot to do and it's not difficult. So many people have asked what kind of grease in it is good for engines and c3 is the engine specification for bearings where Polyrex grease should be. Polyrex is not compatible with lithium based greases and turns into hard rubber. So if you remove gaskets to add your own grease, make sure the old grease is really well removed.