I'm not sure, but since the other 2 are the first they have seen, it could just be wear and tear.
those other 2 then us have the highest mileage they have seen so far.
He told me part of the 20,000K inspection is to inspect/replace some seal/s there, but I don't think many dealers including them do that as it's a pricey operation. And since they are a sealed unit I don't think they do much
They told me one inspection they are supposed to do takes about 8 hrs to do so that would be close to a $1000 bill for us up here and the few they have done never actually needed it
2011 RT Ltd, ISCI floorboards/cruiser boards and LED nut with custom Halo kit and custom Fusion power plant, 50 SPF sunblock and cheap sunglass, total Grfx on bike and matching trailer