1.98" Bearing Protectors & Covers (2-Pack). Bearing Protectors keeps the wheels of your trailer well lubricated is an important part of towing responsibly. Acting like a cap for your wheel bearings, bearing protectors offer two essential benefits for your trailer. First, they provide a reservoir of grease to lubricate your wheels and keep them turning smoothly mile after mile. Second, they cover the bearings so that mud, rain, road grime and other threats to their function are kept out. A bad wheel bearing can start out as a mere annoyance, but before long, it can turn into a huge problem.