Re: Steering Cable broken?
My initial thought is that the big nut is not tightened down all the way. That can cause the cable to slip in/out of the nut.
Have you tried tightening the nut? Teleflex says the nut must be tightened all the way for it to work properly.
I suggest backing the nut all the way off, and inspect for any loose material like plastic or aluminum shavings from rubbing on the nut and make sure the end of the outer cable has the "flare" intact that keeps it from pulling out of the nut. Then grease it up and tighten down the nut all the way. The cable outer housing should not move in/out of the nut when properly tightened.
I just installed a new cable, and I don't recall that the nut can slide on the cable. The flare end may be broken off on your cable and that is why you can see a little black showing between the swedged end of the cable and the big nut.
Back off the nut and describe what you find, post another pic if you can.
Thanks for posting the pic. It really helps.