1981 Dodge Ramcharger steering gone out

Steering problem
1981 Dodge Ramcharger V8 Four Wheel Drive Automatic? Miles

Steering became very hard to turn truck. It was all I could do to turn the wheel then it got easy and then hard again. I parked the truck, jacked it up and with tires off of the ground can turn wheels. Looked at tie rod, it didn't pop or jump around but did hear a poping noise in or around the steering gear box. Also noticed that the universal joint located at the end of steering colom is very slopy. The truck has p/s. Could it be the steering gear box is striped? The p/s pump fluid is full.