This thread sounds so fimilar to what happened to me. After breaking 4-5 10bolts trying to get into the 11's I upgraded to the 12bolt. It worked fine until I started reaching the 10's. First time I broke the posi unit, second time twisted an axle (33 spline), third time broke r&p. So I had enough of it, pulled it, fixed it and sold it. Then bought a 9inch and have yet to hurt it. All of that breakage was pretty much at full weight thought. Now i'm much lighter but also much faster. Hope this helps.