Why are you touching it if you don't know ? Seems like you are just going on it may have a problem, get the car running and drive it, then if it does have a problem you'll know.
Otherwise if it's not broken how would you know if it has a gear noise or bearing noise by looking at it? and then when you take it apart blindly and don't make notes of specific settings and put it back together and now you have a noise that very well might not have been. . . .