When I pulled my sprocket off the Genny armature(using a puller, and a few months ago) even with a nut on for security the nut split and I shredded/splayed the end of the shaft= 'hard basket'.
Today I fixed it, by sacrificing a new nut(3/8"bsf), cut it in half diametrically across the hex,(see photos) and put the halves in place over the thread, and supporting the lower half-nut on a steel plate, carefully hit the flat of the top half-nut with a hammer and drift, reversing the thread distortion effect, starting on the 'inside' and working out to the end. Worked a treat!!
Hope that makes sense, and is help to anybody who does what I do!!
Should work for any thread, but the armature was well worth saving.
Cheers duTch
