Just bought it used and when I shake it it makes a rattling sound. I know lenses with stabilization usually make that sound but this lens hasn't got that.
So, is it normal or is something wrong? It works just fine otherwise
I would recommend viewing the following question and determining if it is working within spec. If it is, then don't worry about it. Even if you do find some random person on the internet that says "mine does that too and works great", what will that tell you beyond further anecdotal evidence?
How can I test a new lens to make sure it is operating correctly?