Posted by Charlie on March 30, 1999 at 22:23:53:
Just finished power steering project. It works! Unlike my M37, the B1PW steering box is inside the frame, and not easily replaceable with a modern box, at least in the same location. I got drag link/hydraulic actuator designed for a Ford F700. I had it shortened and threaded like a tie rod so that its' length can be adjusted when installed. The steering arm (knuckle) end is a tapered shaft. the hole in the steering arm was reamed out to match. The steering arm received a 3" dog-leg strongly gusseted rise to compensate for the new higher arched softer springs. The pitman arm was heated and bent so that the ball at the end points down. The ball fit the drag link perfectly, serendipitously. I put 4 degrees of extra caster between the springs and axle with steel wedges. The drag link/actuator takes pressurized fluid from the Saginaw pump and sends it to a Prince 2" hydraulic ram with a 12" total travel. It is mounted to a fancy piece which bolts to the studs for the diff housing. The other end attaches to the tie rod, of course. The connection is through hydraulic hoses, of course. Amazingly, the feel is decent. Just a bit of extra force to open the valve, not too light, with a palpable return-to-center, probably due to the caster wedges. One nice thing is that there's no added force to the steering linkage till the tie rod level, the steering box/gears and drag link only get slight force. I'm rather pleasantly surprised.
The most expensive and exotic part of this system is of course the drag link. This conversion becomes economically feasible of one runs into such an item for a bargain price or for free. It has few moving parts and I imagine would be fairly simple to rebuild if you found a worn out one. Hydraulic rams are plentiful and cheap. Be sure to get the smallest one. A big one like a 3 or 4" job will be sluggish, heavy and hard to fit. 2" turned out to be enough. 71-77 F250 4X4s used this system, they look like 1.5" or even smaller.
Charlie