Trailering, even a short distance, heats the hubs. When the wheels are submerged during launching, the hubs suddenly cool and the air inside the unprotected hubs contracts, forming a vacuum which draws in water through the rear seals. There is no such thing as a rotating seal that stays perfect. Water and grit thus drawn into the hubs relentlessly destroy bearings. When properly installed and maintained, Bearing Buddy prevents wheel bearing failure and eliminates bearing repacking. Boat trailer wheels can be completely submerged.
