Quicksilver Blog

How to Grease Trailer Wheel Bearings

Maintenance of boat trailer wheel bearings is important both for convenience and safety. No one wants to break down on the way to the launch ramp, and losing a bearing could result in losing a wheel. That’s big trouble! When it comes to trailer wheel bearings, keeping them greased is critical. A quality marine-rated grease like Quicksilver® 2-4-C Marine Grease or Quicksilver High Performance Extreme Grease will protect your hubs and help keep you safely on the road.

Hot Hubs, Cold Water

Boat trailer wheel bearings face a challenging duty cycle. Trailering at speed causes even the most well-greased hubs and bearings to warm up. When you back down the launch ramp and immerse the wheels in cold water, the hubs suddenly cool. Air within the hubs contracts, forming a vacuum that draws water in through the rear seals. Continued exposure to freshwater or saltwater will eventually destroy the bearings. Failed wheel bearings are a common issue in the spring. If the trailer was parked for the off-season, moisture that collected in the hubs can cause the bearings to rust over winter. Traveling on wheels like these, especially at highway speeds, is incredibly dangerous.

For this reason, almost every new boat trailer is equipped with wheel bearing protectors. Bearing Buddy® is one of the original wheel bearing protector brands. The brand is so popular that the name Bearing Buddy has become a catchall term for any bearing protector product. Bearing protectors, regardless of the brand, replace the standard wheel hub dust cap. Each protector has a spring-loaded piston able to maintain slight pressure (about 3 PSI) against grease packed in the hub. This constant positive pressure prevents water from entering past the bearing seal when the hubs are submerged. Grease is added to the hub through a grease fitting (or zerk) located in the center of the piston.

This how-to video demonstrates the process of checking and greasing wheel bearings using Quicksilver 2-4-C Marine Grease, a high-quality general-purpose marine grease that won’t break down in the presence of water and contains PTFE for use in extreme pressure applications. Another excellent choice for trailer bearings is Quicksilver High Performance Extreme Grease, a marine grease formulated for high-temperature and high-load applications.

To check the level of grease within the hub, simply push on the piston. If it rocks or moves, you know it’s under pressure of the spring and all is well. If it does not move at least 1/8 inch, it’s time to add some quality grease to the hub. Load your grease gun with a grease cartridge and add grease until the piston extends beyond the front of the hub. Some protector models have a pressure release feature that prevents over-filling the hub with grease. If you are filling the hubs for the first time, or they were very low on grease, air in the hub will escape after you drive a few miles. Check the protectors and add more grease if the pistons have retracted. Check the bearing protector or trailer owner’s manual for exact instructions on filling your hub model.

Bearing protectors are easy to install and are a good upgrade for any type of trailer. They will help protect snowmobile trailer bearings when towing on salty roads, for example, and can prevent dust and grit from contaminating bearings when a powersports trailer or camper is towed on unpaved roads. In any marine wheel bearing application, you can count on Quicksilver for premium protection. Quicksilver 2-4-C Marine Grease and Quicksilver High Performance Extreme Grease are available in tubes, cartridges and kits that include a handy grease gun..