I have a 97 Ram 1500 4 x 4 318 engine. I went to shift into drive this morning, I hit reverse and then nothing. Does this have a linkage or a cable?

 

It has a shift cable.

 

I have a linkage that came out of the transmission link. What is supposed to hold this place so it doesn't pop out? The linkage pin is 1/4-1/2" the hole in the transmission link is around 3/4". Is there a bushing that fills in the gap? I see a cutter pin on the connector on the top connection, there is a groove around the pin that goes through the transmission link. Am I missing a snap ring or another cutter pin and washer?
the linkage is so Rusted I cannot tell what I am missing

 

Grab the service manual for your truck from here. Should have some good pics of the linkage for you. Parts manuals are also available in the faq section.