Bearings running hot after a long tow

Hot hubs after towing are one of the few things I tell people not to keep driving on. Most common causes: over-tightened or under-tightened bearings from the last repack, failing seal letting grease escape, or a dragging brake magnet on electric brakes. Grab a laser thermometer and compare side to side — more than about 30-40°F difference between the two hubs on the same axle means something's actually wrong, not just normal heat from driving. Repack interval matters more than people think, especially on trailers that sit for months between trips. When was the last repack?