I too use golden clevis' a lot and just use the threadlock/jamnut behind it method. I have not had one failure yet.

Dont try crimping them, you will just weaken the metal or make them worse!

I think that the real problem is that most 4-40 rod has rolled threads which are no where near as good (usually undersize) as machine cut or die cut threads.

Take a 4-40 bolt and compare them.

Andrew