Not personally familiar with this situation but logic tells me, looking at the tire from directly above the axle, you want the tire to pivot towards the side with excessive wear. Tighten one or loosen the other. BUT, I am not experienced with this.
Good question. Could the uneven wear indicate some other work to correct the condition? Bearings wearing out, or tire rebalance? I get uneven wear on my front maybe 3-4000 miles before there tossed.
stay safe & enjoy the ride
check the alinement with the front tire.and the date on the tire ihave run a few old ones that didnt run true