These rear ends are really well built and heavy duty. If you have ever been into a pickup truck these axles are WAY thicker than the axle shifts on one of those as well as the bearings. I have only personally been in my Chevy's rear end. Its a corporate 12 bolt. But the Yanmar is way, way, way thicker than the corporate 12, bearings are also physically bigger. Shafts I know are stronger in this. Bearings are a bit different design and I have not looked up specs on them but I looked up specs on the 6209 nsk bearing. We're no way near the designed capacity of that bearing. Its no wonder they rarely go out.