Watch the controller next to it, observe what relays come in, (or drop out), and when they do so in the stopping sequence.
Does this selector have an advancer panel? What is happening with the dogs and pawls when it "crashes" to a stop? Is it actually dogging out, or are the dogs just dragging the pawls?
I'll see if I can find my operating sequence, but honestly, I haven't used it in 20 years....
