We tore it apart this morning and it is in the shifter case so now we have to go in and see what it is

Ok so I was going on my 77 250sl when I List all gears(i think), I pulled over and started to check it my shift lever just hangs now, when you move it nothing happens and it doesn't feel like its engaging anything inside like it would normally, does anyone know what should have went wrong and what p...