I am going only by memory it has been awhile.
It has been a good 10 yrs since I worked for Ford/ New Holland the metering pumps that were lubed by engine oil are splash lubed by the gear train with a small resevoir around the bottom of the governor assembly which holds a small amount of the old oil when when engine oil is drained . So in the book they want you to add a small amount of oil to flush out the trapped old oil in the pump into the crankcase while you are draining it . The it service manual is vague in some of their descriptions but still a very good manual . They also don't show all the year break changes that were done from year to year .