how tight to tighten planet hub assembly on KMC510?

hi,
I've just used the brute force method of removing a stuck dough hook shaft from a kenwood KMC510. both the shaft and the colar (bayonet) were gnarled up so you couldn't get any attachments back in however using a needle file I cleaned up the inside and took any burrs of any of the shafts and now all of them fit perfectly again !

Only question is, should the retaining nut on the planet hub assembly be fully tightened up or should it be backed off or is there a specific torque setting ? The nut has a rubber o-ring in case that helps to identify what I'm talking about (but given there's only 1 nut holding the planet hub in..think it's fairly obvious which one I mean !)

many thanks for any assistance.
Ant.