I am going to guess that there is a vertical kingpin known as the "master" kingpin and then there is a kingpin in the lower and upper hinge. This was the early form of independent suspension without ball joints.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!