Disconnect the pitman arm from the drag link and turn the steering wheel. If you can easily turn it with one finger lock-to-lock, the steering box adjustment is not the problem. Now go to one extreme and give the steering wheel a firm spin. It should go all the way to the other extreme in three revolutions without stopping on its own. If it won't do this and wants to bind in the middle of its travel, the adjustment is too tight, especially the third one. Go back through all three in-car adjustments until the steering wheel passes these tests.
As Jim/GA recommends, test the king pin bearing tightness. You should not be able to turn the bearings with your fingers with the tires on the ground, but you should be able to do so with the front end jacked up. If they pass this test, you can scratch poorly-shimmed king pin bushings off your list.
While you have the front end up on jackstands, wiggle both front tires inward and outward at the top and bottom. There should be very little if any movement laterally. No movement is ideal, of course. This test will tell you whether the king pins and their bushings are in good shape.
With the drag link still disconnected from the pitman arm and the wheels off the ground, push and pull the front wheels from side to side as if you were going around a corner. There will be more resistance in doing this than when spinning the steering wheel with the drag link disconnected because of the weight you are moving: backing plates, heavy brake drums, brake shoes, spindles, tie rod, etc. But you should be able to go back and forth with only minor resistance. If this test passes muster, the tie rod end plugs are not too tight. If it is difficult to move the tires back and forth, back out the tie rod end plugs 1/2 turn at a time until the wheels can be moved back and forth with relative ease.
That only leaves the drag link end plug adjustment. Reattach the drag link to the pitman arm and adjust the end plug per recommendations given here so far. Test resistance via the steering wheel. If it's difficult to turn the steering wheel, back the drag link end plugs out another half turn and try again.
Once you have done all the above, sit on the ground straddling the driver's side front tire. While you move the tire back and forth, front to rear, watch the drag link connection at the pitman arm. If you see the arm moving before the drag link does, tighten that end plug 1/2 turn and test again. You want to reach a point where the pitman arm and drag link move at the same time without binding or undue stiffness. Check the front of the drag link the same way. The steering arm should move at the same time as the drag link does.
If your steering box and front end pass all these tests and the car still steers hard, check the front axle's caster, meaning the angle at which it leans backwards at the top. I believe that angle is supposed to be 5 to 7 degrees. If less than that, the steering will be hard. Stand a short L-square against the bottom of the front axle's raised lip and ensure that the flat side of the L-square is perfectly level on the ground. Measure the distance between the L-square and the TOP edge of the axle. It should be 1/2", which is close enough to that 5 to 7 degree caster figure. If the measurement is in the ballpark, the front end caster is o.k. and you can eliminate that from the list of suspects.
Also check the tire pressures. 34-36 psi gives the best all-around performance for ease of steering and tire wear.
Did you observe whether the sector shaft moves up and down inside the housing bushings? If it does, the bushings and/or shaft are worn and should be replaced. Looseness here will not cause hard steering, but slop at the steering wheel will be obvious. The usual cure by some guys (and usually the wrong cure) is to tighten the drag link and tire rod end plugs - which does not solve the problem and only makes steering more difficult. Rarely does over-tightening a Model A steering component compensate for wear in some other steering area.
'Just thought of another oddball cause of hard steering. Ensure that the bottom of the steering wheel hub is not rubbing against the top of the metal quadrant. This can happen only with two-tooth steering columns because the column jacket has not been pushed down far enough over the top bearing race in the gear box. If the steering wheel is rubbing here, it will cause hard steering with and without the pitman arm being connected to the drag link.
Ouch! I've got blisters on my fingertips from typing. Check out these suggestions while I let my bleeding fingertips rest up before typing the next SHORT response.
Marshall
