I can see there is a shear loading at the top and the bottom, yet since the axle does rest on the bottom of the knucle joint as well there would be a lessing of the shear because of that. Its not as simple as it first appears. Castor and inclination also affects it too. I have searched for good information on this and have not had any luck. My concern is the aftermarket, and most likely off shore produced reproduction parts for classic trucks, ie don't want to be driving down the freeway and have a kingpin come apart.
