Super A steering arm movement

Guys-

I want to apologize in advance for posting this, but I've been through the archives and haven't seen this particular problem.

The steering arm on my '53 Super A rises and falls when I turn the steering wheel. I don't get much play out of the wheel, but the shaft the arm rides on rises about 1/2 to 3/4 of an inch before it starts to turn. Once the shaft has risen into place everything is tight and steers fine. I've made sure that the shaft and arm are moving together.
When I'm mowing, the front wheels bounce back and forth as I run through the many hoofprints in my pastures, and I'm worried about doing damage to the steering gear. There is no end to end play in the shaft running from the steering wheel.
The schematic at the IH website shows a bearing at the top of the shaft as well as a retainer for the bearing. Could this be a possible cause of this problem, or might I just be able to tighten the nut at the bottom of the shaft? Somebody please give me some good news, as mowing season is upon me and down time is a bad thing right now, though I realize not being able to steer at all would make the downtime that much harder.
Once again, I apologize for posting a question you've all probably answered before.

Thank you,

Wesley

The upper bearing is shot you need to rebuild the wholr assy when you take it apart i have rebuilt several and you need new bushings,seals amd bearings as it sounds like your wholr assy is shot and while you have it apart do it rite.

Thanks. That wasn"t what I wanted to hear, but it is what I knew was coming. Maybe I can finish my mowing this one time and then dive into a rebuild before things gat too tall again.

I really appreciate your advice. Thank you very much.

A month or two back I did the same thing with my Super A....

It has to come all apart.. take the front end right off...

photos here...

http://www.jarootfarms.com/photogallery/thumbnails.php?album=2