What needs to be replaced?

I should have asked this question before I tore my iPod apart, but from what I remember, I would try to load songs onto it, and it would cause my iTunes to lock up. I tried using disk utility on it multiple times in some sort of attempt to fix it, but I couldn't seem to repair the disk using that. I realize that nearly all signs are pointing towards the HD being the issue, but I just want to see if anyone else has had this problem before. I wouldn't want to order a new HD and have it be something completely different! Thanks!