28 dec 2019
28 Dec 2019 followup note: I'm happy enough with this steering box, ratio and all, that I've abandoned plans to replace ths steering system with something more modern like rack and pinion. In practice while it's not ideal, even driven at speed as ersatz sports car it's quite usable.
This is it. One box. No optional ratios, you steer, or don't. It's a Nash steering gear, very tiny, and turned upside down to fit in the American. The pitman arm comes out the top of the box, not the bottom, and it's grease filled from the factory, so it's a safe bet that the pitman arm bushing runs without lubrication for decades.
I got this one to rebuild at my leisure. It had been repaired once; the pitman bushing is a bronze insert in the iron casting, but someone had bored it out and installed a plain steel bush, hich means OEM type replacements would not fit. My solution was to bore the steel insert to accept an OEM bushing, which has a gap, so I spent the time to buzz tiny bits off the bore to get the clearance about perfect.
Otherwise, all of the other bearings were good. I checked and set clearances, it's very nice and tight now. I wish I had spent the time to adapt a needle bearing insert on the pitman, to eliminate all play; as it is designed, there will always be some.
I made sure it is sealed well (Permatex "Right Stuff") and it's now filled with 90 weight gear oil; hopefully if I keep it full and/or oil moves around in the box the pitman arm will stay lubricated.