TB42 distributor question

[BadMav]

Ok, this one has me stumped and although nothing is actually playing up, I noticed when setting the points in the old thing that the rotor button (and the whole top section of the distributor shaft for that matter) can be rotated anti-clockwise a good half turn before stopping on the advance mechanism. The truck drives fine and the advance mechanism seems to work as normal (checked with a timing light) so I'm not really concerned about it.

I'm just wondering if this is either normal or a pre-cursor to something in the advance mechanism failing altogether?

[PGS 4WD]

I think what you are feeling is the mechanical advance.

[BadMav]

That's what I'm thinking, but I've never seen half a turn (not sprung either) of mechanical advance. Only the usual 30 ish degrees before binding up on the advance springs. I'll pull it out and check it anyway.

EDIT: Found that the shaft is snapped, but in a way that it hooked the top section and kept driving it.