If you had equal number of turns right and left previously, that's definitely a clue that something went wrong inside the steering gear. The worm may have "slipped a tooth" so to speak if the balls were being spit out of the nut. Or it's always been that way.
ADs originally came with steering stops that bolted to the king pin wedge bolt, but most trucks don't have them anymore. Probably because whoever changed the kingpins way back when neglected to put them back on. On the rebuild instructions for the steering gear, it cautions against letting the nut with the recirculating balls go all the way to either end of the worm, even by gravity as it will damage the ball retainers. That may be what happened to 47 chev's steering gear.
