Money to spare is one of those things right? I'm gonna pull it apart and grease it.....if it blow sup when I'm on a trail some day I'll just decide I was wrong. I apprecaite the info that that youtube was awesome. the rebuild itself is about $400 which is pennies compared to what I assumed it was gonna be.I think you’d know if they were clicking. If they’re not, I’m sure they’re fine and could just use a good servicing. However, you won’t really know until you get in there. If you have the money to spare, it’s not like it hurts to replace them and know you’re 100%, but my guess is it’s not necessary. For now I would just check the grease level like you said, and top off as necessary before you do the rebuild.