When
undertaking trailer maintenance, the wheel bearings should be the most
important item on your list. And as a box trailer owner, it is a job you should
feel confident doing. This way, you’ll know what state the wheel bearings are
in and that the job has been done properly.
Bearings are
comprised of a cup pressed into the hub and the cone, which contains the
bearing rollers. When inspecting the cone, look for signs of wear, pits, chips or
discolouration of the rollers. Also, inspect the cup for wear, damage or
scoring marks. If any damage is found, the bearings should be replaced.
In an
emergency, you can remove the cone and replace it with a new one with a
screwdriver. However, a copper dolly is the ideal tool for the job. A copper
dolly reduces the likelihood of damage to the machined surface, if you slip.
While
replacing a wheel bearing may seem an intimidating task, by following these 10 steps, you’ll become an expert.
Step 1
The first
step is to take off the wheel and hub. Remove the tire and wheel from the
trailer and use a flathead screwdriver to remove the grease cap by prying it
off in a circular motion.
Step 2
Next, remove
the castle nut on the spindle. The castle nut should be visible after removing
the grease cap. Wipe the extra grease off the nut, then look for a “tab” (one
of the castle nut notches). Push the tab back toward the spindle with your
screwdriver. You may also see a “cage” surrounding the nut, which can easily be
pried away in a circular motion using your screwdriver.
Step 3
Now, remove
the hub. Use a paper towel to hold in the outer bearing as you pull off the
hub. If the hub is stuck, rock it in a circular motion to help it slide off. If
the bearing is frozen to the spindle, you’ll need to knock off the hub with
some force. Remember, even the smallest of nicks can wear out the bearings and
their seals very quickly. If there are nicks in the spindle where the bearings
and seal sit, consider replacing the spindle or the entire trailer axel.
Step 4
Once removed,
disassemble the hub. Firstly, remove the outer bearing, by pulling out the
outer bearing and spindle washer, and set it aside. Now, remove the inner
bearing and seal. Place the hub on a cinder block, with the wheel studs facing
up, and place a 2.5cm wooden dowel to knock out the bearing.
Step 5
Clean and
inspect the bearings, looking for nicks and dents in the roller cage. If you
see these problems, or lines, spots or discolouration of metal, discard the
bearings. If everything passes inspection, clean out and dry the bearings.
Step 6
Next, check
the seal. If the seal is no longer round, or the rubber looks dry rotted, the
seal should be replaced. Oftentimes, removing the grease seal from the hub causes
enough damage to require its replacement.
Step 7
The next step
is to repack the trailer bearings with grease (ensure you fill every space of
the bearing). To repack the bearings by hand, place a gob of grease in your
palm and press the bearing into the grease with force.
Step 8
Insert the
inner bearing and seal by turning the hub over so the front sides of the wheel
studs face down. Place the inner bearing in the hub and install the seal on
top. Tap the seal in a circular motion until it sits flush. Then, apply a thin
layer of grease to the spindle, and slide on the hub.
Step 9
Insert the
outer bearing and seal by sliding it in while rocking the hub back and forth
until the bearing is seated soundly.
Step 10
Now, install
the castle nut, by tightening it until it stops or becomes snug. Rock the hub
and push in to ensure the hub is properly seated onto the spindle. Then,
tighten the castle nut as needed.
