Is that a 2 blade oval disc?
Hi Tyler, yes it is.
G'day N1KK0 and Tyler
I usually just put a spacer at the end of the crank but if the hub is loose you could put the same width spacer on
the step in the crank (other end of hub) but you would have to file key way slots into the spacer washers although
with washers just at one end of the crank it should be fine as with most mowers the hub doesn't lock up tight to the crank shaft
Hi Max, I believe I've tried putting spacers just on the end of the shaft - and that caused the blade boss to be able to move up and down the shaft as it wasn't pushed up against the 'step in the crank' as you mention. I think this was causing issues for me but I can try again, its a fuddy little system they have down there, very fiddly.
Will try again tomorrow and see if I can kind an extra 5mm or so. Thanks again.