by Bob Belding

It’s that time of year again when I take my family on weekend day trips. And every time we travel, we see a trailer on the side of the road with a missing wheel.

It may be a camping trailer or a boat trailer or a ulility trailer, but whatever kind of trailer it is, it was probably lacking maintenence.

Most trailer owners know how to check the obvious, such as lights and wiring harnesses and the connections, hitchball and trailer tonge connections and, of course, tire condition. The one thing many trailer owners overlook though is the wheel bearings.


Use jack stands!
Safety first!


This is the hub with the bearings removed. The hub and races have been cleaned.


What a typical bearing should look like when it is cleaned.


The hub assembly on the trailer with a castle nut installed and a cotter pin.


A bearing that has been repacked.


The back side of the hub with the bearing installed, ready to have the new seal installed.

A great boat!
Done! let’s go fishin’

The wheel bearings are one of the most important parts of your trailer. They hold the wheel hub assembly onto your trailer and they allow the wheels to spin freely. If you are not cleaning, inspecting for wear, and repacking the bearings at least once a year, you are taking a big risk. The wheel assembly could come off on the highway, putting your life and other motorists’ lives in danger, not to mention wrecking whatever you are pulling!

Repacking the wheel bearings is fairly easy. You will need a good jack and jack stands. Once the wheels have been removed you will have lots of room to access the dust covers on the hubs. Remove the dust covers, the cotter pins and then the castle nuts. When the castle nuts are removed, you can pull off the hub assembly from the trailer and remove the outer bearing.

If you flip the hub assembly over you will see a grease seal. Remove the grease seal and the inner bearing. Be sure not to mix the outer and inner bearing up because they are matched to their bearing races.

To clean these parts you should use a varsol parts washer. Once these parts are clean, inspect the bearings and the races inside the hub for pitting of metal and burning of metal. If you notice this you should replace the bearing and race assembly. If they appear to be o.k. then get ready for the messy part of the job.

Now that the bearings are clean and dry, repack them using high pressure wheel bearing grease. Make sure that you get lots of grease between the roller cage and the inner race that is attached to the bearing. A bearing packer makes doing this very easy and the tool is fairly cheap and easy to use. Oh yeah did I mention that this is the messy part of the job?

Now that the bearings are repacked, install the inner bearings in the hubs and install new grease seals, then place the hubs on the spindles and install the outer bearings, the washers and finally the castle nuts. When installing the castle nuts you must preload the bearing using the nut, you tighten the nut as tight as it goes then back it off until the nut can be handled by your fingers. Then tighten it by hand and install the cotter pin to lock the nut in place. If you decide to tighten the nut as tight as it goes and leave it there you will be picking your wheel up off the ground within a few blocks because it will burn the bearing off completely. So make sure you follow this step!

The last thing to do before putting the wheels back on is to install the dust cap and if it is equipped with a grease fitting give it a couple of pumps of grease from a grease gun. Any good repair shop can handle this kind of job if you do not feel comfortable trying it yourself. Prices will vary.

If you have this service done at least once a year there will be a lot more happy campers on the highway during holiday season!

Bob Belding is a licensed automotive technician at Acacia Motors in Ottawa, Ontario.

Connect with Autos.ca