Koni Adjustable Shock Won't Adjust...'84 FC

[dthollis1961]

Went to adjust the 3 year old Konis on the FC today. The right one
was set in the loosest position, and I adjusted it to about 3/4 firm.
Took the left one off to adjust, and when pushing the shock down to
engage the adjuster, it just spins. I can feel a slight detent, but
pushing as hard as I can and even tapping with a mallet, it won't
engage. Any other secrets to these shocks? Thanks.

David Hollis 84 FC33(owned by Jeff and Ernie previously)
Springfield,IL