What's causing this tire wear?

I like low pros. Just ride better. Maybe get away from Michelin's

 

With heavy loads on rough roads you should get 2-250k on a good quality shock. Smoother roads or lighter loads 300k+.

Without looking back, did you say you balance your tires or have those aftermarket tire balancers? Out of balance tires will cause some funky tire wear too.

 

I want to revisit the shocks, I think @supersnackbar might be onto something, you did a visual inspection on the shocks? Did you try to jar them at the mount points?

 

Speaking from first hand experience that kind of tire wear is due to low air pressure awhile ago . Once the wear pattern starts , even with correct air pressure , it will continue for the life of the tire .

 

If you walk into the TA or Petro shop they have some pictures of worn tires and what causes them. I have one inside dual doing the same thing as yours. Rotated for now but going off the picture on the wall they recommend new shocks.

 

This was also my first thought. Everyone is different but I personally get best tire wear by keeping the tires set at the max recommended cold psi.

 

Hub bearing shot? No it'd make a hideous noise

 

I would throw a set of shocks at it. Just my .02