I noticed today on my way home from a local lake that I smelled somthing that smelled like burning metal. I noticed on my dual axle boat trailer that the back axle, the one with brakes, had some smoke coming out of the grease fitting. A few minutes later, the other side popped out the grease plug housing and grease plopped out. The wheel cap that houses the grease fitting from where I saw the smoke was extremely hot to the touch. What does this mean? Bad bearing/s?