We don't have a differential on the drive axle -- too heavy for our tastes and besides, the vehicle is designed to pretty much stick to a straight line. We still need a way however to ensure we aren't binding as we drift around off the straight and narrow. We also need a one way device on the prop shaft to keep the prop from backdriving the transmission (especially the spool transmission) if we get a sudden wind shift.
The solution was three ratchet hubs that will mate up to our kart axles. Of course as has been the case with most of the parts on this vehicle, no one seems to stock DDWFTTW ratchet hubs anymore. After about 16 hours (12 in the first one and 2 hrs each in the others) I finally finished them up this evening
Construction details in previous post.