Sounds like the select cable is broken. That is the cable that moves the linkage left to right.
www.rodneydickman.com sells replacement cables that are a direct replacement..
The cables is a shiethed wire, The wire corrodes and weakens over time and will just snap.
I replaced mine in '06 after 19 years. The hard part is taking off the center console and running the new cable through the firewall. Use some lock tight on the fastening nut when you reconnect the linkage.