Wheel bearings are crucial components of your dirt bike and knowing when and how to replace them is an essential maintenance skill. When you notice movement in your rear wheel between the swing arms, it's usually a sign that your wheel bearings need attention. In this comprehensive guide, I'll walk you through the complete process of replacing your dirt bike's wheel bearings.

Note that it’s a tricky process, best is to watch our 20+ min video as well.

Required Tools and Materials

• JMP Puller Kit with slide hammer

• Flathead screwdriver

• Circlip pliers

• Socket set (24mm socket specifically)

• Hammer

• Lithium grease

• Degreaser

• Clean rags

• New bearing set (we're using Prox bearings)

• Rubber seals (typically included with bearing set)

Preparation

Start by removing the wheel spacers from both sides - these should easily pop off with your fingers. Next, you'll need to remove the outer seals. Using a flathead screwdriver, carefully pry under the seal's edge and lift it out. You'll likely notice accumulated grime and dirt inside the hub - clean this thoroughly with a rag before proceeding. Both sides.

Pro Tip: When cleaning, pay special attention to removing all debris, as this will make the bearing removal process much easier.

Removing the Old Bearings

Before removing the bearings, you'll notice one side has a circlip while the other doesn't. Start with the circlip side:

• Using circlip pliers, compress the circlip

• Use a small flathead screwdriver to lift the circlip while keeping it controlled

• Remove the circlip completely and store it safely - you'll need it later

Using the Bearing Puller

The JMP Puller Kit is essential for removing bearings without damaging the hub. Here's how to use it properly:

• Select the correct die size (25mm for most dirt bike wheel bearings)

• Loosen the die to allow the segments to move freely

• Insert the die at a slight angle into the bearing until you feel it click

• Tighten the die to secure it against the bearing

• Attach the slide hammer and ensure its fully threaded

• Use quick, controlled pulls to remove the bearing

• Remove the bearing from the die

• Flip over the wheel and repeat the process

Pro Tip: While some riders use the old-school method of a hammer and bar, the bearing puller prevents hub damage and makes the job much cleaner.

Preparing for New Bearings

Before installing new bearings, proper preparation is crucial:

• Clean the hub thoroughly using degreaser like the a9 racing all in one spray

• Remove all old grease and debris ( both sides )

• Inspect the hub for any damage

• Prepare the new bearings by applying lithium grease around the edges

• Pack the new rubber seals with grease in the ridge area to prevent dirt intrusion

Pro Tip: Filling the seal's inner ridge with grease creates a barrier against dirt and debris, extending bearing life.

Installing New Bearings

The installation process requires attention to detail and proper sequence:

• Start with the circlip side of the hub

• Position the new bearing and use an old bearing as an installation tool

• Tap evenly around the bearing (top, bottom, left, right) to maintain alignment

• Once flush, use a 24mm socket to drive the bearing fully into place

• Install the circlip ( use the a9 oil again)

• Add the new (greased) rubber seal

Installing the Second Bearing

Flip the wheel over

Before installing the second bearing, don't forget this crucial step: insert the inner tube spacer between the bearings. Sometimes riders forget this component, which can lead to a redo of the work. Then:

• Clean and grease the second bearing

• Position it carefully, ensuring alignment

• Use the same tapping method as before

• Drive it flush using the 24mm socket

• Install the new rubber seal

Final Steps and Spacers

The final stage is critical for proper wheel function:

• Clean both wheel spacers thoroughly with degreaser

• Apply a light coating of grease to both spacers

• Insert spacers into each side of the hub

• Check for smooth movement - spacers should rotate freely

• Verify both seals are flush with the hub

• Double-check all components are properly seated

Important Tips for Success

Always work systematically and keep your workspace clean

• When tapping bearings in, maintain even pressure around the circumference

• Never force components if they don't fit

• Keep the circlip under control during removal to prevent it from flying off

• Pack seals with plenty of grease to prevent dirt intrusion

• Always verify free movement after assembly

Common Mistakes to Avoid

• Forgetting to insert the inner tube spacer between bearings

• Using too much force when removing old bearings

• Damaging the rubber part of new bearings during installation

• Installing bearings unevenly

• Forgetting to clean and regrease spacers

• Not packing the seals with enough grease

Final Thoughts

While replacing wheel bearings might seem intimidating at first, having the right tools and following this systematic approach makes it a manageable maintenance task. The JMP Puller Kit makes the job significantly easier and helps prevent expensive damage to your hub. Remember to take your time and pay attention to detail - proper bearing installation is crucial for both performance and safety.

By following these steps and using quality components like Prox bearings, you'll ensure your dirt bike's wheels spin freely and reliably for many rides to come.

Author information

My name is Charlie Frost, and I'm no stranger to the adrenaline-fueled world of extreme enduros. Starting my journey at 19, I seamlessly blended trials and enduro racing, honing my skills through youth events and extreme races like the Tough One and Erzberg. When I'm not tearing through rugged terrain, you can often find me in front of the 24MX camera, sharing my passion and insights with fellow riders, as we delve into the exhilarating world of off-road racing.