I had a similar problem on my CJ-2a. My local jeep expert cut a 1/8" slit
vertically in the casting, straight through the area where the locking wedge
goes, and replaced the locking wedge with a bolt ground into a wedge shape. By
tightening this the bellcrank shaft was locked firmly into place, eliminating
the play. It's not an especially elegant solution but the alternative would
require cutting off the supporting bracket, having a machine shop install a
bushing and then weld the asssembly back into place *accurately*, a time
consuming and expensive amount of work.
-sjd