Trying to find the spindle diameters for the two different year ranges of 3/4 and 1 ton axles.
So far I'm guessing (by looking at section 6.3 in the 29-54 parts manual.)
That the older axle has spindle diameters of 1.40" and 0.84" (inner and outer respectively)
That the newer axle has spindle diameters of 1.5" and 7/8"
I've got an early one stashed somewhere in my shop and a late one in place under one of my trucks.
But easier yet is to check the Restoration Pack specs for each.
1950 Inner: 1.4051 to 1.4056
Outer: .8427 to 8432
'51 and '52 are the same.
1953 Inner: 1.4986 to 1.4991
Outer: .9052 to .9057
So the break seems to be between '52 and '53 with a small increase in spindle diameter.
The kingpin diameter on both the early and late axles is the same. Some of the other specs seem to vary, but I wonder if swapping from the early to the late spindles might be a way to solve the seal problem.
If swapping spindles isn't a solution, it's sure easier to swap a '53 or '54 axle under a '47 to '52 truck than it is to cut and weld an axle from a much later truck.
