1515 Rattling Sound - Bearings going?

[Revorocks]

Just been checking a motor I am selling and noticed that when it spins on its own, it sounds like something is rattling.

The motor isn't that old, and has never been abused. I've taken it apart and there is nothing wrong with the rotor or the windings.

Only thing left is the bearings, but they seemed ok when I took it apart.

To turn the motor it's pretty stiff, quite a lot more than my other 1515 and the 1717. Also, it rattles when it spins.

I made a video explaining the problem, and yes I know about how you shouldn't rev them with no load, but it's only running 4S, so it shouldn't over rev.

http://www.youtube.com/watch?v=kApiCymFVnY

What can I do in getting replacement bearings. Will Castle warranty replace things like that? If so will I have to send it off?
I would rather avoid sending it off as it takes ages. If I have to though I will just buy my own but can someone tell me what size, and how to remove the old ones.

Thanks