Dexter Axle recommends wheel bearing lubrication every 12 months or 12,000 miles. Don’t forget to replace the grease seals when you do the bearings. Also, for trailers with brakes, while the drum is off, check the brake shoes and magnets for grease contamination, as well as the inside drum surface. Clean if necessary with a cleaner designed for use on brake shoes. Brake shoes and magnets contaminated with grease indicate over greasing and bad grease seals.