Hi Clogs,
When you rotated the head it is possible that one of the tee nuts has
got caught up in the access slot where the tee nuts fit in the radial
"T" slot .This is most likely to be in the position facing forward when
you stand in front of the machine ,slacken each of the nuts a little and
try to rock the head a little whilst just feeling if the nut /tee bolt is in position.
My Warco mill had a similar situation until modified.
Good luck.
John