One of the most important components of a boat trailer is the hubs. The hubs are what keep your trailer in motion. Without question, improperly maintained bearings within the hubs result in the wheel seizing, thus failing to move. I have maintained numerous trailers and can assure you that with proper routine maintenance, you are far less likely to encounter any surprises. Learn how to grease trailer hubs properly. 

What Purpose Does The Grease Serve In A Trailer Hub

It is important to first understand the wheel’s speed of rotation as you’re towing a trailer along the highway. The bearings are under a significant amount of strain and, without grease, will heat, seize, and fail. 

Unquestionably, the grease creates a barrier between moving parts. The barrier is necessary because it prevents metal from rubbing on metal. For this reason, trailer hubs with insufficient amounts of grease face tremendous levels of friction. 

Friction within a hub is detrimental as the hub will freeze. I, fortunately, have never had a bearing lock while trailering a vessel. However, I have seen it happen, and it is not a good situation. 

What Happens If A Wheel Bearing Goes Bad While Driving

Unfortunately, a multitude of things can happen if a wheel bearing goes bad while driving. 

More times than not, you will have a warning before the bearing completely fails. One of the early signs is feeling vibration and hearing sounds from the wheel with the bad bearing. 

Secondly, the tire begins to wear unevenly. If you notice inside or outside wheel wear, I recommend inspecting and repacking with grease or replacing the bearings. 

Third, the wheel becomes incredibly hot as a result of the friction from the lack of grease. The heat is likely to cause axle components to melt together. It should be noted that in some cases, the wheel will catch fire. 

Lastly, in the event the bearing seizes, the wheel will no longer spin. When traveling at a high rate of speed, you are at risk of the wheel becoming separated from the trailer. As you can imagine, this is an incredibly dangerous situation. 

Select The Best Trailer Wheel Bearing Grease 

Unquestionably you will want to use a high quality trailer bearing grease. Low quality and low grade grease break down at a more rapid rate in comparison to heavy duty high grade greases. 

I highly recommend Lucas Oil Marine Grease as it includes additives to withstand marine environments, such as launching and retrieving boats from trailers.   

In addition to grease, a grease gun is necessary to inject the lubrication to the position of the bearings within the hub. The ValueMax Mini Grease Gun Kit is ideal because it is designed specifically for the 3″ Lucas Marine tubes of grease. The grease tube slides into the gun and is interchangeable when the grease has been used in its entirety. 

Steps For How To Grease Trailer Hubs 

It should be mentioned that you will want to have all the necessary supplies on hand before greasing the bearings. The supplies include paper towels, a grease gun packed with a grease tube, and rubber gloves. Needless to say, you don’t need much. 

It is important to grease every wheel hub, no matter if your trailer is fitted with two wheels or more. 

Gather Supplies

To begin, have all supplies on hand and ensure that the trailer is in a safe location where you are not at risk from passing vehicles. 

The most central point of the trailer wheel is the hub. Hubs are what allows the wheel to spin as a result of the bearings within. Locate the hub and remove the rubber gasket on the dust cover cap. 

Prepare The Hub

Once the rubber gasket is removed, you will have access to the zerk fitting. The zerk fitting allows for the grease to flow from the gun when connecting to the zerk and into the bearings. 

Importantly, before you begin pumping grease, you’ll need to place a paper towel on the ground beneath the hub. Without question, greasing fittings is a messy job. 

Grease The Bearings

Next, attach the hose of the grease gun to the zerk fitting. Ensure that it is well seated on the zerk.

After the grease gun is connected, begin pumping. You’ll want to pump the gun until all of the old black grease is pushed out the front of the hub. Unquestionably you will notice a difference in color once the new grease appears. Once the new grease is visible, stop pumping to avoid damaging seals. 

Once you’re done applying the grease, remove the hose from the fitting. With a clean paper towel, remove all access grease within the dust cover cap carefully. The reason I say carefully is because the inside of the cap has a sharp edge. Trust me, I have cut myself numerous times. 

Lastly, once the access grease is removed, reinsert the rubber gasket to prevent water from entering the gasket housing. 

Greasing Trailer Hubs Is An Easy Task

Unquestionably, greasing trailer hubs is an easy but necessary task for a boat owner. The process of how to grease trailer hubs is about as easy as it gets when it comes to maintenance. I recommend adding bearing greasings to your annual maintenance regimen. Fortunately, the process has worked for me, as I have never had a hub go bad.