I also have a tub diverter spout that's not working right; water
still comes out of the spout when I pull up on the lever. From
reading this forum, I'm sure it needs to be replaced.  Previous
answers say that the spout is either a "screw on" or a "slip
on". I checked underneath the spout and it has a slot at the
wall. Assuming it was a "slip on", I got out my allen wrenches,
got underneath the spout and tried to find the set screw. As far
as I could tell, this spout doesn't have one.  Could it be that
the slot is there as a grip for some sort of tool?