From a paper on steering by Vern Terdel (this was prior to his booklet being published).
Bearing end play is adjusted by shimming the lower race which protrudes slightly from the case. The end cap is installed to determine the size and number of gaskets needed.
Adjustment is a cut-and-try process. Begin with three thick green gaskets between the end cover and the box. There should be a very slight drag on the steering shaft when it's turned. If there is no drag, remove one gasket and check again. If there is too much drag, add another gasket, a thinner brown one. If you don't hit the right combination at first, be patient; you'll soon get it and then be ready to assemble the steering box.
Adjust the lash until the steering turns smoothly, with no play, throughout the full movement from lock to lock and back. Then, install the star lock on the adjuster screw and screw on the locknut to hold the star lock in place.
There is also good information on VanPelt's site:
http://www.vanpeltsales.com/FH_web/f...tmt1937-48.htm
This is also good information:
http://www.vanpeltsales.com/FH_web/f...stmt-notes.htm