I second Jim's suggestion that binding steering U-joints are a problem.

You can check easily with the front of the car up on on jackstands.
While you're at it check the ball joints, tie rod ends, etc for slop.

I asked a local pro mechanic what he does since there's no Zerk fittings on the u- joints. He cleans first with brake cleaner and then greases with wheel bearing
or Mobil-1 synthetic grease then wraps the joint with Saran (plastic) wrap.
That sounds creepy to me. But If you put grease it will quickly collect road crud
so maybe a better deal is to Grease and install a boot?
see here for universal u-joint boots:
https://www.mcmaster.com/products/universal-joint-boots/
Dunno how much hassle it would be to install.

Another thing is BZ's steering fluid is north of two decades old.
Has anyone tried flushing their P/S gear? I'd like to know what works.

BZ, please post back with your findings, and Happy 4th, Bill