Have not checked that, Zebrafive. We can see what looks like the end of a shaft protruding from the pedal mount. It looks sorta like a welded area on the end of the shaft...might just be paint and dirt. It is barely visible in one of the photos I posted. We were concerned about dislodging something that might be broken, so we left everything alone. I'll find some time in the next day or so to look at that more closely. If it is sheared, could the pin be replaced without pulling the axle housing? A nagging worry in the back of my mind is if any internal parts of the diff lock are actually broken and would potentially dislodge and fall in a bad place like the inner axle bearing or brake mechanism.