Frequent use of your boat or recreational vehicle trailer in and around mud, water and other harsh environments can put its wheel bearings at risk from debris, water and dirt contaminating the grease that keeps them spinning freely. Knowing how to inspect and repack wheel bearings is critical to their continued smooth operation and can increase bearing life and decrease chances of failures on your tow trailer.

Wheel Bearing Construction

The ultimate function of a wheel bearing is to keep your wheels rotating as smoothly as possible without unnecessary friction. It does that thanks to sets of steel ball bearings or tapered bearings. Either design is held together in a metal ring and lubricated by grease packed in and around them. The wheel bearing fits inside a hub enclosure on the axle shaft that seals out the elements and contains grease to keep them lubricated.

How Often to Inspect Your Bearings

Always follow the maintenance schedule for your trailer as outlined in your owner’s manual and adhere to any directions referring you to have inspection or replacement completed by a certified factory mechanic. As a general rule of thumb, you should inspect your wheel bearings once per year. Trailers that are frequently immersed in water should be inspected more frequently. During inspection, you can determine if bearings need to be replaced by looking for deteriorated or missing balls or rollers, scoring, flaking, heat spots, corrosion or cracks in the metal housing, or simply cleaned and repacked with new grease. 

How to Clean Bearings and Replace the Grease

As mentioned, the wheel bearing is packed with grease, which is one of the critical components for reducing friction and preventing rust. With time and use, grease eventually breaks down or dries out from exposure to heat, dirt or moisture. When the wheel bearing is removed, it’s best to first wipe as much excess grease from it using a disposable shop rag. This can be a potentially messy process, so wearing latex mechanic gloves is a good idea. Once the excess is removed, follow up with Quicksilver® All-Purpose Spray Cleaner or Quicksilver® Contact Cleaner. These general purpose cleaner/degreasers penetrate dirt, grease and grime and are easy to spray on and wipe off. Repeat the process until the bearing is clean.

Applying grease to a new or cleaned bearing is a relatively easy process and can be done by hand. Place the bearing in the palm of your hand, scoop a generous dollop of grease with the other and press it into the bearing, making sure it squeezes through to the other side thoroughly. Use enough grease to fully pack the bearing.

What Type of Grease to Use

Marine grease is your best choice and is typically formulated with tackifiers that stick better to the bearing’s metal surfaces and won’t break down from contact with water. Marine grease also contains additives such as corrosion inhibitors to protect against rust, corrosion and pitting. Quicksilver offers two great options:

• Quicksilver® 2-4-C Marine Grease with PTFE is a lithium-based, NLGI 2-rated grease. An NLGI 2 rating means it has a thick consistency for use in higher operating temperature ranges and at high speeds, making it ideal for wheel bearings in trailers and automotive applications.
• Quicksilver® High-Performance Extreme Grease also has an NLGI 2 rating and is a versatile calcium sulfonate‑based grease suited for a wide variety of uses in automotive, RV, motorcycle, ATV, snowmobile and trailer applications.

Inspecting, cleaning, and repacking your trailer wheel bearings regularly provides extra peace of mind by reducing the chances of costly and aggravating failures spoiling your favorite recreational activities.