My oil bearings have view windows. One of the widows looked bright, almost white. I drained all four and refilled all four hubs. Actually I flushed the white one; that is, emptied, filled, emptied and refilled. Look at the difference in color from the hub with the white window and another hub. The white bearing oil is from water seeping into the hub, the dark color oil is from a healthy hub. The manufacturers data calls for 50 weight oil, will SAE 20W 50 be OK?
It’s mid season folks check your gear.