The larger AD trucks, 1.5 and 2 ton most often do have only a small cap with about five 5/16" bolts covering the splined end of the axle flange.
But the 3/4 and 1 ton AD trucks all have the bolt in axle flanges.

Grigg


1951 GMC 250 in the Project Journals
1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-