Sounds just like what my 2000's rack is doing. It's tight until it gets warm. I can go 2-3 miles, then it gets loose. Mine makes no pops. Bad Rack. I'm saving up for that, LBJs, UCAs, OTRs, shocks and a water pump.
I mean, seriously, if you can see the shaft turning going into the rack (like mine does), yet no movement comes out from that input, BAD RACK. The good news is they come with inner tie rods already installed...... but they're ~$180 + an alignment.