While sitting here and reading through my Ford Gun Tractor parts book (Hey, Keefy, that's one thing that didn't leave Lithgow in the middle of the night!
), I came across an interesting item:
C11Q-4299 Thornton-Welles Automatic Locking Differential (Optional, when specified).
Which vehicles specified these locking diffs? How many were put into service? Are there any diagrams or repair manuals for these?
More importantly, what does "Optional" mean? Does this mean that a Field Battery purchasing Major could stroll into a Ford dealer and ask for an FGT with metallic paint, air con, 8 speaker stereo and a Thornton-Welles locking diff?