Checking a duel mass flywheel

Hi All
What do you look for when checking a DMF with the gearbox and clutch removed for serviceability.
Thanks Roger

you need to see how mutch play there is i think that 30mm is to mutch but no sure and the problem i had was it was dished buy 2 or 3mm so only the out side edge of the clutch plate was worn i replace my flywheel with a new one but will fit a solid one if i have any problems again in some ways i wish i fitted a solid one last time
Transmission -

Thanks Martinhollings. Very useful. At least it gives me an idea.
Roger 47