Question on 3160 center pulley

[JR Scout]

Does the center pulley on the 3160 have a set screw to keep pressure on the bushing slot key like the outer pulleys have, or does it just use the tightening of the split bushing to hold it at the right height on the spindle?

I don't see a threaded hole in the pulley for one, but as you might guess from my posing the question, it spit the key and slid down the spindle shaft after I tightened the bushing as much as I could without breaking the bushing.

[tst]

the center is tapered so it wedges into place