How to Replace Trailer Bearings

Trailer bearing replacement might sound like a tough job, but it’s definitely doable, and we’re here to walk you through it. Whether you’re doing it for the first time or just need a refresher, this guide will help you get the job done right.

• How-to video
• Tools needed for the job
• Prepping your trailer
• Removing the hub
• Removing the inner bearing
• Cleaning the assembly
• Installing new cups
• Packing the grease
• Reinstalling the hub
• Installing new outer bearings
• Torquing the castle nut
• Tips for ongoing maintenance

Because replacing your trailer bearings can feel like a daunting task, it’s helpful to see and understand what you’re working with. Here is a breakdown of a typical hub assembly. Take note of the position of the bearings and seals, as these will be the focus of our removal and installation efforts here.

1. Jack and jack stands to lift and support the trailer
2. Lug wrench or impact wrench for removing and tightening lug nuts
3. Flat-head screwdriver for prying off the dust caps
4. Needle-nose pliers for removing the cotter pins
5. Seal pulling tool for removing the inner grease seals
6. Brass drift punch for removing and installing bearing cups
7. Hammer to use with the drift punch
8. Lint-free towels for cleaning grease and surfaces
9. Brake cleaner for thorough cleaning of the hub assembly
10. Seal punch or seal set kit for seating new bearing cups and seals
11. Rubber mallet and block of wood as an alternative for seating seals
12. Bearing packer for packing bearings with grease (this one’s optional!)
13. Grease suitable for trailer bearings
14. Torque wrench for properly tightening the castle nuts and lug nuts
15. Breaker bar for adjusting the castle nuts
16. New cotter pins for securing the castle nuts

First things first, you need to get your trailer up in the air. Always lift your trailer by the frame, not by the axle or suspension, since they aren’t designed to hold all that weight.

Make sure the frame is properly supported before you crawl under there to start working.

Now that your trailer is lifted and secure, let’s get that tire off.

Start by removing the lug nuts with a wrench. If you’re using an impact wrench, just be sure to let the socket come to a full stop before moving to the next lug nut, so you don’t accidentally damage them.

Once the nuts are off, you can go ahead and remove the tire and set it aside.

Next up, you’ll see a dust cap covering the hub assembly. Grab a flat-head screwdriver and carefully pry it off by working around the edge. Take your time with this part—it’s easier than trying to rush it.

With the dust cap out of the way, you’ll see a cotter pin. Use some needle-nose pliers to straighten and remove the cotter. Best practice is to replace the cotter pin with the bearings, so once removed, the pin can simply thrown out.

Now, take off the castle nut by hand, followed by the washer underneath, and finally the entire hub -- yep, the whole brake hub comes off at this point! When you do go to remove the hub from the spindle, just be sure you keep a hand over the opening so the outer bearing doesn’t fall out.

To get the inner grease seal out, you’ll need a seal pulling tool. Don’t worry about damaging the old seal since you’ll be replacing it with a new one shortly. If you see any grease on the hub assembly, wipe it off right away. Grease and brake shoes don’t play well together!

Next, carefully remove the inner bearing and clean out the old grease inside the hub with a clean towel. Again, clean up any drips on the hub as you work.

Finally, flip the hub over and clean off any remaining grease from the outer bearing cup.

To remove the inner bearing cup, grab a brass drift punch and a hammer. Place the punch at the edge of the cup and gently tap it out. It’s okay to take your time!

Do the same thing for the outer bearing cup, supporting the hub on some blocks of wood.

Lastly, toss the old cups — they need to be replaced whenever you change the bearings, so there’s not need to same them for re-installation.

Now that the bearing cups are out, it’s time to give the hub a good cleaning. Yes, you’ve already cleaned up your grease spots as you removed the bearings and seals, but these puppies need to be immaculate!

Use a lint-free towel and some brake cleaner to wipe down both the inside and outside of the hub. You want to remove every bit of old grease, brake dust, and rust. Be extra thorough here — any leftover grease can cause problems down the road.

At last we begin the re-installation process. Congratulations! You’ve made it this far. You got this!

With the hub clean, you’re ready to install the new bearing cups. Start with the inner cup, placing it so the thicker side is down.

Use a seal punch or a brass drift punch to tap it into place until it’s firmly seated.

Flip the hub over and repeat the process for the outer bearing cup. If you have a seal set kit, it’ll make this step easier, but a drift punch will work too.

Before you install the new bearings, they need to be packed with grease. Start with the inner bearing (we’ll do the outer bearing in the next step).

Take a generous amount of grease and put it in the palm of your hand. Press the widest end of the bearing into the grease, working it between the rollers. Keep rotating and packing each roller until the entire bearing is well-coated.

Gloves are a good idea here to keep the grease clean. If you have a bearing packer, use it! It’s quicker and less messy.

Once your inner bearing is packed with grease, apply a light coat of grease to the bearing cup and pop the bearing cone into place. Then, take your new grease seal and apply a light film of sealant around the outer edge. Make sure the seal is lined up squarely with the hub’s seal bore before you press it in.

If you have a seal set kit, use it to press the seal into place, or you can gently tap it in with a rubber mallet and a block of wood.

The seal is fully seated when it’s flush with the edge of the hub.

With the inner grease seal installed, it’s time to slide the hub assembly back onto the spindle. However, it’s a good idea to clean the spindle before you install the hub assembly to make sure no old grease gets into the new stuff. Use a lint-free towel to thoroughly wipe down the spindle.

Now let’s install that outer bearing. Pack the new outer bearing with grease just like you did with the inner one, and install it into the hub. Carefully slide the outer bearing into the hub assembly, ensuring it sits snugly in place over the spindle.

Then, place the outer bearing washer on top of the bearing. This washer acts as a spacer and helps ensure everything stays properly aligned.

Once the bearing and washer are in place, wipe away any excess grease that may have spilled over, keeping the area clean for the next steps.

The goal of this step is to properly seat the bearings and grease seal. Begin by installing the castle nut by hand. Once the nut is hand-tight, grab a torque wrench and set it to the appropriate ft. lbs. as specified by the manufacturer. For our example, our torque setting is 55 ft. lbs.

After you’ve reached the proper torque, use a breaker bar to back off the nut slightly before re-tightening it by hand.

Finally, slip the new cotter pin into the castle nut and bend it to lock everything in place.

Reinstall the dust cap by gently tapping it over the hub assembly, making sure it’s fully seated against the hub.

Next, it’s time to put the tire back on. Line up the holes with the spindles, and start each lug nut by hand to avoid cross-threading.

Once all the lug nuts are started, use an impact wrench to tighten them in a star pattern. This helps seat the wheel properly.

After everything’s tight, lift the frame again, remove your supports, and slowly lower the trailer back to the ground. Finally, use a torque wrench to tighten each lug nut to the recommended specs, following the same star pattern.

You did it! You successfully replaced your trailer bearings! Give yourself a pat on the back and a much-needed break with a cold beverage and a comfortable chair.

One important note: you’ll need to conduct some post-install torque checks. It’s fairly simple. After you’ve driven increments of 10, 25, and 50 miles, check the torque on your lug nuts to make sure they’re still snug. Re-torque if necessary. It’s also a good idea to check them regularly during routine maintenance.

Proper maintenance is key to prolonging the life of your trailer bearings and keeping your trailer towing smoothly. Now that’s you’ve installed new bearings, you’ll want to keep them at top performance for as long as possible.

One of the most important tips is to regularly check and re-grease your bearings. Trailer bearings should be greased at least once a year, or more frequently if you’re using your trailer often, especially in harsh conditions like water or dirt. Over time, grease breaks down and loses its effectiveness, so keeping your bearings well-lubricated helps prevent wear and overheating.

Another best practice is to inspect your bearings for signs of wear or damage during routine maintenance. Look for any pitting, rust, or discoloration on the bearings and races. If you notice any of these signs, it’s time to replace the bearings before they fail on the road. Additionally, always replace the grease seals when replacing bearings to ensure a tight, leak-free fit that keeps contaminants out.

Lastly, it’s important to use high-quality, water-resistant grease designed for trailer bearings. This type of grease is formulated to withstand the extreme conditions that trailer bearings often encounter, such as immersion in water or exposure to dust and dirt. Make sure to follow the manufacturer’s recommendations for grease type and ensure that your bearings are packed properly, either by hand or using a bearing packer, to provide even coverage and maximum protection. Taking these steps will help you get the most out of your trailer bearings and avoid unexpected breakdowns.

Disclaimer: These photographs, recommendations, and approximations are intended for demonstration purposes only and do not reflect the specifications of any particular tow vehicle, recreational vehicle, or trailer. Always consult the manufacturer’s Owner's Manual.