Adjusting manual steering box.

The service manual talks about proper preload first then adjusting the mesh.
I think I am interested in the preload adjustment which is the large, like
3" diameter threaded part that is where the shaft goes into the box. The mesh
adjustment then uses the slotted stud with a locknut.

All my parts are new, including the gear box which is too tight because I have
to bring the wheel back after turning a corner. I am not sure the mesh alone
will loosen this will it?