Thanks for that. I have done some repairs on these before but not in the gearbox/drum area. I note that when the cycle is finished and the machine is empty you can put your hand inside the drum and rotate the front against the back section. It doesn't really make any grinding or undue noises. I suspect perhaps this is a gearbox issue? It is perhaps getting noisier in contra-rotate mode. I don't understand enough about the gearing. I guess the front drum is attached to a spindle that goes through to the gearbox at the back. Perhaps it is rotating where it should be fixed at the front? Or if there is a central gear at the back on the end of the shaft, maybe it is slipping against the spindle?
I also have a CR02 which is software locked and it would appear, having engaged the servo manually, mechanically seized, (opposite sort of issue, ironically!!) which does work fine though, so I will substitute the two machines and as you suggest take the gearbox assembly off the CR01 and have a look. It's a shame because the machine is otherwise still going well. Any other suggestions or advice would be appreciated.