Nissan hardbody (1989) speedometer cable not connecting on the transmission side?

[prancerman88]

my speedometer broke and so i took the old one out to see why it broke. I left it out and drove around for about a week waiting for the new one to come in and now the cable isnt connecting on the transmission side
like as in the woodruff key on the cable isnt getting held in

the cable is the right cable

I took a video of the output gear (because the exhaust is in the way to see) and I dont see the corresponding indent for the woodruff key and the hole seems kind of too deep in general
is it possible that there is some that fell out while I was driving and if so does any one know what it is called so I can get a new one. thanks