Dyson cr01 washing machine fault code F15. part replace ?

We now live in SW France and own a Dyson cr01 washing machine(whilst in the UK we had numerous updates and repairs) but now all repairs have to be D.I.Y...We had fault code F15 show up and following an answer on this wonderful site, from 'Richard Seymore', spot on thank you !!! I have looked at the servo motor/rack and pinion gear to throw in the contrarotating enclosed gears in the hub of the machine and found the large round grey plastic/nylon rim attached to the rack part of the servo assembly to be siezed not allowing the rack to be fully moved in one direction.
A little WD40 and work has freed it off, it now works fine, but I notice that the large round top hat section, part of the rack gear assembly, which is held in place by tongues screwed into the main tub housing is split( the part that had siezed up) at about 11 o'clock....IS THIS normal as made please, or, do I need a new unit, if so does anyone know the part number and are there any suggestions as to how to fit it please ?