I have noted that, if the bearing seal is intact on these machines, the bearing will last almost forever and it is by no means the problem people often think it is.
It is of high quality and while a Dyson drum may seem heavy, it is small compared to a sports cars weight and what this bearing was originally designed to hold up.
I would first check that the drum is indeed loose, open the doors and try to lift the metal drum assy up and down. If you can feel any slack then you are probably correct, the bearing has failed.
Please note, the movement of the whole tub assy, when you push the drum about isn't the same thing and completely normal.
The other common issue is the whole tub assy touching the front casing. This happens particularly when in spin, this rubs on the rubber seal, jolting the tub and making the assy rotate as if there is a bearing issue, the tub moves excessively and noisily too.
This can be cured very simply, as the machine just isn't level. Just lengthening the front feet a bit, so that the tub sits further back in the chassis. This small adjustment completely cures what looks like a catastrophic bearing problem, to once again have near silent operation.
While Calgon is a waste of time on a normal machine, it is wise to use it on a cr01, as to remove any lime-scale build-up on the yellow slip bearing separating the drums.