I have 1 trailer wheel that's starting to turn black The wheel didnt spin super easy and it has 1 spot during its revolution where it sounds like it could be rubbing against the brake pad. I've taken off the wheel and grease cap, the castle nut seemed too tight so I backed it off a little. There was no play, the bearing seems fine, it doesn't look like it's leaking grease. A buddy of mine thinks the brakes are out of alignment and that the black stuff is brake dust but it seemed almost tar like. Any thoughts? Is it safe to tow with it like this for a little while? My wife and I close on our house in less than a week and I need it to get stuff out of our house. Thanks in advance!