tire wear problem

A while ago I changed my driver side ball joints cause they were shot and the pass. side was fine. I have noticed that my tires have worn out very funny and it was only the pass. side... the tire has plenty of tread left on the inside of the tire and towards the middle it is noticably lower and the outer part of the tire is bald why is this? my alignment is 1/8 in to prevent dw which i had pretty bad and the tires didnt have a problem then. after the swap they wore out all funny, the pass. is still bald and the driverside is just starting to go out like the other one but it just started whats the deal??

check your TREs?

all new except the pass. side but it has no play at all thats what i figured to so I checked it and its fine.