at the moment I am trying to take apart one of our older grinders to refurbing it to go back on the bar. it was taken out of service and a spare put in it's place due to an overly sticky dosing lever. the back-up needs to come off the bar, it is not up to the task, and is deffinitely overheating and generally being a pain. sooo, i am taking apart the old doser and have come up against a roadblock.

I need to remove the lower dosing star to get at the little eccentric washer dealy that sits underneath, as that is where all of the friction is coming from.

The thing is; i can't for the life of me recall how it is supposed to come off.

To begin with I have removed the little set pin, and if i recall correctly the lower doser star "should" just screw off the central bolt, but it is a big no go. what am i forgetting/ what is the trick?

any help would be greatly appreciated.
chris ganger