WTF steering: 72 4x4 K5

[mister.freeze]

I've read so many threads about steering that suddenly got stiff, but no resolutions. I know I'm not the first, nor will I be the last. What's up with my steering????

OK, so here's what happened. For years (going on 20 now that I've had my K5), I've had light, responsive steering. 1 finger could turn lock to lock, at idle, in gear, with the tires on the ground. No bump steer or significant play. For some reason, the steering wasn't centered after an alignment, but I could live with that. Just be for a trip to Austin (from Houston) I topped off the power steering with fluid (Prestone power steering fluid with stop leak) because the hydraboost had been seeping and I just wanted to be 100% for the trip. I did this after my 10 mile commute from work. Backing out of the driveway, the steering was stiff and the pump was groaning.

I fought this all the way to Austin and back. Gone was the smoothness and responsiveness. I had a big gap between 11 and 1 o'clock, and the wheel stayed wherever I left it; no self-centering. I figured that since I had been running ATF for so long the PS fluid was too thick or even incompatible and causing my troubles. So I got home and replaced the pump, gear box, AND Hydraboost. I even removed the steering dampeners. No change. I even drained the fluid and went back to ATF. Nothing.

I've heard all kinds of muck about ball joints, U-joints, slipping belts, worn gear boxes, etc. What's the official word? What happened, in the span of 10 minutes, that I haven't yet been able to resolve?

Thanks in advance for any input or help. I want this fixed and for this thread to be the answer nobody seems to be able to post.