Do you see gear oil leaking from the rear wheel? Is your vehicle making a
roaring sound that follows the vehicle speed from the front or rear? Do
you wonder how difficult it is to change the front or rear axle seal and bearing
or bearing hub? You have come to the right place. We are a team of ASE certified online mechanics that have created this guide for you
to save you money while having the satisfaction of doing the job right.
Most vehicles axles bearing are basically the same and are either straight
axle (rear), independent suspension (CV axle) or bearing hub styles. We have a
complete list of these different styles of axle bearing replacements and an
explanation for why they go bad and what happens when they do.
If you are not going to do the repair yourself this guide with videos will show you what
you are paying for when you take your vehicle into a repair shop.
A bearing is made of high grade steel which has a
super hard coating over the rollers, inner and outer races. A bearing goes bad
when this coating is worn away due to mileage or extreme load which just leaves the normal
steel which then degrades and destroys the bearing components. Also, failures
can occur when moisture combined with salt from roads penetrate the seal and
contaminate the bearing, or over time the grease used to lubricate the bearing
can liquefy leaving it dry causing a failure.
This is what a failed axle bearing looks like. You can see the roller cage is
broken and there are pits on parts of the rollers themselves.
Here is a close up of the bad bearing roller. This is what happens when the
bearing starts to fall apart. Parts of metal get caught up in-between the
rollers and the upper and lower bearing race while under high pressure. This
creates a grinding action which can be felt while driving the vehicle. These
bearings are used in the front hubs and rear axles of all vehicles. Some CV axle
bearings are actually two sets of ball bearings put together but fail the same
This is what happens to the bearing race once the bearing goes bad. Here is
an example of what happens when the metal particles from the bad roller is
pressed against the race under high pressure. A race in good shape will be smooth
and flat, a machined surface.
What Happens When the Bearing Goes Bad?
When a bearing hub fails
it allows the front wheel to wonder around causing irregular tire wear and steering
characteristics. Another symptom of a failing bearing is a roaring sound that follows the vehicle's speed
from either the front or rear end. A front bearing failure will change in tone
when you steer the car right or left while the vehicle is in motion. A trick to
locate a bad bearing on a front wheel drive car is to raise the front of the
vehicle so the wheel are not touching the ground. While placing your hand on the
coil spring spin the wheel rapidly. A bad bearing will give a distinct vibration
if is it has failed.
A bad bearing will also allow the brake rotor to contact
the brake pads and push them back into the caliper which will
cause the bake pedal
to go to the floor. If a bearing is bad and neglected it will cause the
wheel to lock up in which case at this point the differential will most likely
need to be replaced because the threads on the housing will be too badly
damaged or the bearing will be melted onto it. It can also cause the wheel to
fall off because the axle, hub or bearing will melt allowing the wheel, lug nuts
and axle flange to become separated from the car.
When an axle bearing or bearing hub fails, it may cause the wheel to have play
from top to bottom, but not always. Grasp the tire firmly and jog the wheel back and forth
and from top to bottom to confirm the failure. On straight axle differential style of vehicles a bearing failure
will be indicated by leaking gear oil.
If you are not replacing the brake pads then you don't need to open the bleeder or push the piston back into the caliper for this job.
If the rear axle bearing and seal is being replaced you will be dealing with
gear oil so have a fluid catch basin ready. Identify the side of the differential you see the leak
or hear the noise on before performing the repair. Also, if the gear oil has been leaking for a while you
will need to
emergency brake shoes. If one bearing has gone bad you should replace all of
them. The effort of the job is in the labor, the bearings and seals don't cost that much
A complete list of tools, parts and repair manuals are at the end of this guide.
Wheel Bearing Hub Replacement
To get an idea on what you are in for with this repair please watch the video
below and then read down through the guide to pick up on additional information
which is updated regularly. Let's get started.
Step 1: Remove Bearing Hub Mounting Bolts
If the vehicle is equipped with ABS it will have a
wheel speed sensor which will need to be disconnected before removing the bearing
hub. Once this has been done locate and remove all axle bearing hub mounting bolts
which is located behind the spindle. The hub will become loose.
ABS wheel sensor connector removal
The bolts size is 15mm, 17mm and 18mm in most cases and will be fairly tight
so be ready. Position the wrench or ratchet to push downward to loosen. If you are
lifting upward it can hurt your back which is no fun especially when you have the
reminder of the job to do.
Step 2: Match the New Bearing Hub
Once the old bearing has been removed, match the old bearing assemble to the
new unit to ensure a proper installation. Always use a top quality factory (AC Delco,
Ford, Chrysler) replacement parts because these bearings have added strain on
them especially when you have large tires on the vehicle. The bearing below has
an ABS sensor included.
Step 3: Installing the New Bearing Hub
While holding the new axle bearing hub, install the mounting bolts by hand to avoid cross threading.
Then, tighten evenly in a star pattern to manufacturers specifications (70-85 ft pounds). These bolts can be installed with thread lock for added protection against
loosening. Reconnect the ABS wiring connector and reassemble the remainder of the job as described in the linked repairs
CV Axle Bearing Replacement and Spindle Removal
A CV axle bearing is one piece bearing that incases the inner and outer
bearing into one race with seals at either end. Once disassembled, this bearing
is removed by pressing the bearing from the front or rear spindle. These bearing
will go bad much like any other bearing but the replacement is a little
Step 1: Remove the CV Axle Flange Nut
Once the steps in the above guides are complete you will end up with the
vehicle looking like this. This is in the rear so you will have the emergency
brake shoes present which wouldn't be there if the job is being done in the
front. Use a pair of pliers or dikes to remove the bearing hub nut
cotter pin. If air tools are not being used you will need to do this step with
the car still on the ground to hold the wheel from spinning while loosening the
nut. These bolts are fairly tight so you will need to use a breaker bar to
Using a large socket remove the axle nut from the bearing hub,
we are using air tools so it makes the job easier. They have rechargeable impact
guns that don't use compressed air which cost about $70.00 on Amazon.
Once the nut is broken loose you can remove the nut completely.
This will expose the lock washer which will still be on the CV axle against
the wheel hub. Use a small screwdriver or pick to help remove the washer.
Step 2: Remove the ABS Sensor and Parking Brake
If the vehicle is equipped with ABS
the wheel speed sensor will need to be removed either at the mount or at the
electrical connector. This is ensure the sensor does not get damaged during the
repair. After removing the mounting bolt, grasp the sensor and remove it you might notice fine metal
particles over the magnetic end of the sensor this is from the bearing failure and
must be cleaned off before reinstalling the sensor.
Step 3: Remove the Parking Brake Cable
If doing this job on the rear (only) of the vehicle you must
remove the emergency brake shoes and cable. Once the shoes and springs have
been removed it is time to remove the cable from the backing plate. Locate and remove
(release) the cable housing retainer clip. This step can vary by way of a
multi fingered retainer which is released from the outside of the backing plate
which is found on American built vehicles.
Grasp the emergency brake cable firmly and pull it outward from
the backing plate, (Note: Pliers can be used to help in the removal).
Step 4: Remove Suspension Bolts
While using a wrench to back up the rear swing arm nut, use
a socket to remove the through bolt.
Remove the forward swing arm bolts from the bearing housing
Locate and remove the trailing arm mounting bolt from the lower
Using a sharp object such as a scribe, mark the location of
the strut mounting bolts so they can be reassembled in the same location.
Mark the strut to spindle alignment which also helps preserve
the rear camber adjustment if any (alignment).
Use a socket and wrench to loosen and remove the strut mounting
bolts, (leave the top bolt in without the nut) the spindle can become loose so keep
your hands on it.
Step 5: Remove the Spindle
After all mounting bolts have been removed, grasp the bearing
housing and spindle and work it outward and away from the drive axle. The drive
axle can get stuck and may need help by pushing it outward through the hub. At
this point the spindle will be loose and then there are two options, either you can
take the unit to a automotive machine shop or visit this guide to do the
CV axle bearing replacement yourself.
How to use
a hydraulic press to replace a CV axle bearing
Step 6: Reinstall the Spindle
After the new bearing has been installed lift the assembly into place. Slide the upper strut bolt through
the spindle bolt hole while feeding the axle through the wheel hub. Spin the hub
to help align the axle splines.
Next, insert and tighten the lower trailing arm bolt using a wrench or
socket. This bolt should be fairly tight, you can use thread lock to ensure
it doesn't come loose during its operation.
Then align the rear swing arm bolt hole and install and tighten the
bolt and nut assembly.
Install and tighten the front swing arm bolt and nut.
Finally install the bottom strut mounting bolts and nuts. Tighten
both while keeping the scribed line in alignment with the strut to retain the camber
adjustment. This should conclude the suspension arm reassembly portion of the
repair. Double check all suspension arm bolts for tightness to ensure proper
Step 7: Reinstall Parking Brake Cable
Install the parking brake cable into the backing plate housing,
reinstall the retainer clip if equipped. On some designs the cable simply pops
into place and is held in position by spring loaded retainer clips.
Step 8: Reinstall ABS Sensor
After cleaning the sensor free from metal particles, install
it back into the spindle. Then install and tighten the mounting bolt and
reattach the wiring harness into the retainer clips.
Step 9: Reinstall Axle Nut
After all suspension bolts are tight, reinstall the axle wheel
hub washer. This washer is unidirectional and can be install either way.
Sometimes these washers can be damaged in which case it should be replaced.
Then, install the axle nut by hand to avoid cross threading.
Using a torque wrench tighten the axle nut to manufacturers specifications
(usually 140-180 torque pounds). This can be completed once the tire is on the
ground to help hold the tire in place.
Once the nut gets close to the tightness desired, align the cotter pin holes for easy installation
while reaching the proper torque.
Insert a new cotter pin, use dikes to bend and cut the long side of the pin
to hold it in place. You are now all set, continue to reinstall the parking and
disc brake assembly. Also reinstall the wheel and torque it to manufacturer