I think thats something common. My toshiba hdd that came originally came with my TR started clicking about 5-6 months (I guess) after purchase. A few months before it crashed it became even more frequent and data used to get corrupted occasionally. My new one hasn’t yet started the clicking and hopefully it will stay this way for long.
Some people say that the clicking noise comes from the heads being parked but according to me that doesn’t make sense else shouldn’t that noise come right from the beginning?