How to Grease a Trailer Axle

Greasing a trailer axle involves lifting the trailer, removing the grease cap plug, attaching a grease gun to the zerk fitting, and pumping grease while rotating the hub until fresh grease pushes out old lubricant.

Lubricating the Super Lube axle hub on your RV or trailer keeps your wheels spinning freely. It’s a process that should be completed about every 36,000 miles or 12 months, whichever comes first. Luckily, the process is extremely easy, and all you need are some trailer jacks, a grease gun and the appropriate grease for your axle. In this post, we’ll walk through the process of how to grease a trailer axle so that you can hit the road smoothly.

If water is present around the grease fitting, the grease appears old or contaminated, or if there is an insufficient amount of grease in the fitting, your axles should be greased using the following procedure. Before you start, you’ll want to make sure you’re using the proper grease that’s indicated in your axle owner’s manual.

To grease trailer axles, jack up the trailer, access the zerk fitting, apply grease while spinning the hub, and continue until fresh grease exits, then clean excess and reseal the cap.

• Step 1: Jack up your trailer using appropriate jacks.
• Step 2: Remove the rubber plug from the grease cap. 
• Step 3: Place the nozzle of the grease gun onto the zerk fitting found behind the plug. Be sure the nozzle is completely engaged onto the grease fitting before continuing.
• Step 4: Begin pumping new grease onto the fitting using a grease gun. To evenly coat the bearings, spin the hub during grease application. The previously used grease will begin to exit the bearing cavity through the outer bearing.
• Step 5: Remove the grease gun as the new grease begins to seep from the fitting.
• Step 6: Clean up excess grease with a paper towel or shop rag.
• Step 7: Push the plug back onto the grease cap.

And just like that, you’re done! Depending on how frequently you use your trailer, you may need to grease your axles more than once per year to keep them spinning easily and freely.

Note: If the Super Lube hubs are separated from the axle assembly, seals must be replaced prior to lubrication. Failure to replace the seals before lubrication may result in contaminating the brake linings with grease.

Now that you know how to grease a trailer axle, you may be wondering why yours is equipped with Super Lube. This type of greasing system is standard on all Lippert axles up to an 8,000-lb. capacity. Super Lube makes changing grease in your axles cleaner and easier than other greasing methods. It requires no disassembly of wheels or hubs and fills the entire bearing cavity with grease, allowing for complete submersion. Pumping new grease through the zerk fitting purges old grease for a complete repack and offers better long-term protection over standard hubs.

Even though the process is straightforward, a few common errors can lead to long-term damage. Pumping grease too quickly can blow out seals, while using the wrong grease type can reduce lubrication performance. Skipping hub rotation during application often results in uneven coverage. Taking a slower, methodical approach ensures proper distribution and protects internal components.

At Lippert, we build a full line of reliable spring and torsion axles to meet unique specifications for a wide range of trailers. Our spring axles are ideal for utility, dump, enclosed, flatbed and landscape trailers as well as equipment haulers. Torsion axles work best with cargo, marine, agricultural, equestrian and purpose-built trailers.