Nissan CV joints

I know, not mustang, but I dont want to go sign up for some forum Ill never use again, and someone here probably knows.

Why is it important to mark the allignment of the axle, inner race, and ball cage? What happens if they are not assembled in the correct allignment?

I marked them with a sharpie (directions showed a marker), but when it was time to reassemble those marks were gone.

Now the car makes a humming or winding noise that gets higher pitched as speed increases and lower as speed decreases.

Any chance that this is just a typical freshly rebuilt cv joint noise?

just incase this might help anyone else, the sound was coming from the hub bearings. I had tightened down the hub nuts too tight. I backed them off, and the noise was gone. I didnt think i could hate front wheel drive cars any more than i did, but after having to pull the axles and rebuild all of the cv joints, wow. RWD FTW. Thanks for the replies.