05 Durango 2wd SLT with 4.7. Started off with a (clunk/jerk?) in the steering wheel at a certain point in both directions that seemed to get worse over time.

I stopped at the store last week, and when I went to leave I had no power steering. Drove it home and found no leaks and full of fluid. Decided to go ahead and replace the pump/reservoir just in case. I drove it around for a while and the power steering slowly started working. I pulled into an empty lot and did a few full circles in both directions and everything seemed to be working perfectly, until I went to pull out and had nothing again. Now the power steering is only working intermittently. Is this all a sign of a bad steering rack? I don’t want to throw a bunch of money into it if there could be another cause.