Shifting problems

[SpencerW1198]

I have a 2003 2500HD silverado with the Allison transmission. A week ago I left home with it and the shifting was fine, but when I got to town it would not go into park. It shift through all other gears perfectly, but when I pull the shifter back it will slide up to where park is, but instead of locking in and engaging, it softly springs down into reverse, I'm not sure if I can adjust it or I need a new cable

[gmtech4]

Cable is broken where it goes into it mounting bracket at tranny , the "fence staple " retainer clip is most likely gone and the tabs are bent over on themselves ,

 

I've seen it a few zillion times