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BMW E39 5-Series & M5 Front Wheel Bearing
Replacement
(Model Years 1997 - 2003)
by Dave Zeckhausen
How to determine if you need new wheel bearings
E39 5-Series and M5
front wheel bearings are not known for being robust and are common
replacement items for racers. If you experience a low rumbling
sound, as if you have studded snow tires or if you experience
pad knock-back, it may be due to
bad wheel bearings. If you have high mileage
(75,000 +), it is a good idea to replace the wheel bearings as a
preventative measure while you are performing other work with
overlapping labor, such as shocks or brake rotor replacement.
If you have no symptoms and
are not performing maintenance with overlapping labor, we do not suggest bearing
replacement simply due to high mileage. E39 bearings have been known to
last beyond 130,000 miles. Save your money and spend it on things that
really need replacement!
The M5 uses different front bearings than the non-M5
models. Make sure you buy the proper bearings for your model. See
details and installation instructions below.
* Pad knock-back occurs as the
result of high lateral g-force from sweeping, high-speed turns.
The wheel bearings/hubs deflect and the rotors push the pads back.
Then when the car is pointed straight, there is a gap between the
pads and rotors. The next application of the brakes results in
significantly longer pedal travel, as the pads move to close this
gap. When unexpected, knockback can be a rather startling
experience.
Parts Required from your BMW parts
counter or aftermarket supplier
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BMW Part Number |
Description |
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31-22-1-093-427
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525i/528i/530i/540i Wheel
Bearing
(1 per side)
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31-22-2-229-360
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M5 Wheel Bearing
(1 per side)
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31-20-6-779-384
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M12 x 1.5 (55mm long) bolts
(4 per side) |
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31-30-6-779-823
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M12 x 1.5 (95mm long) pinch
bolt
(1 per side) |
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33-32-6-760-374
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Self-locking nut for pinch bolt
(1 per side) |
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QTY(4) Bearing Bolts with Loctite
QTY(1) Pinch Bolt
QTY(1) Nut for Pinch Bolt |
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Required Hardware (1 set per bearing) |
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M5 wheel bearings have the same internal design as 528i/530i/540i
bearings; however, they have three raised dowel pins which mate with
matching holes in the M5 rotors. M5 bearings will not fit an E39
525i, 528i, 530i, or 540i with stock brakes.
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If this is your first time changing E39 wheel bearings, you should budget
three hours for the job and plan on two hours for the first side and one
hour for the second. Subsequent bearing swaps take about 45
minutes per side, assuming you have air tools. |
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The wheel bearing/hub assembly
is secured from behind by four bolts. Two of the bolts are easily
accessible. The other two are blocked by the shock absorber.
This turns what should be a 5-minute job into the more complicated
process documented below.
If you are contemplating
replacement of your front shocks, there is almost 100%overlapping labor
with the bearing replacement, so you should consider doing both at the
same time.
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Installation
Instructions
Safety Warning:
Working on your own
car can be dangerous. Even quality jack stands can collapse if not
positioned properly, and a floor jack can fail suddenly and without warning.
You can be seriously injured or even killed if you do not follow proper
safety procedures. Please use both a floor jack and a pair of jack
stands to support your car so a failure of any single support is less likely
to result in the car falling on you! Zeckhausen Racing LLC assumes no
liability expressed or implied for the improper installation or use of these
components.
Note: The
following steps are performed on a 540i and are the same for the M5.
The 6-cylinder models (525i, 528i, 530i) have a different suspension
configuration and these instructions, while close, do not apply exactly.
You may wish to consult a service manual or a BMW mechanic before
attempting this service.
 Place
the car on jack stands and remove the front wheels. Remove the
brake calipers and rotors. I've upgraded to a big brake kit, which
is why my brakes look different. Be careful of the black metal
dust shield, which can be sharp and may cut your hands if you aren't
careful.
If you are installing a
big brake kit and your car has more than 60,000 miles, it is a good idea
to change your bearings at the same time.
The factory shock
absorbers are the same part number for left and right sides. Marks
on the back of the strut ("L" and "R") are lined up during installation
with a slot on the back of the steering knuckle. Rather than using
those marks, it's easier to draw your own with a marker. Clean the
dirt off and mark one or two vertical lines on the strut and the
aluminum knuckle.
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A closer view of the alignment
marks. A horizontal line is not required since the strut has a
shoulder that sits firmly in the knuckle. Also, the strut will
have a sharp boundary between the clean and dirty sections, so it will
be obvious when it is seated fully in the knuckle.
Once you've marked the strut,
remove (and discard) the pinch bolt, which is shown to the right and
slightly below the alignment marks. Use a wrench on one end to
keep the bolt from rotating as you remove the nut.
The pinch bolt holds a small
bracket that supports the ABS cable and, on the driver's side, the brake
pad wear sensor cable. After removing the pinch bolt, simply push
this bracket out of the way.
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Remove the 18mm nut and bolt holding the front lower control arm to the
chassis. A good whack with a rubber mallet should pop the arm out.
Label the bolt so it isn't confused with the strut pinch bolt removed in
the previous step. When reinstalling, the bolt goes in from the rear
and the nut faces the front of the car.
Note: If your BMW has auto-leveling Xenon headlamps, you will need
to disconnect the suspension height sensor from the passenger's side
control arm.
Remove the nut from the swaybar end link where it
attaches to the aluminum bracket. Use a 16 mm open end wrench to
prevent the stud from turning while you remove the nut. Wiggle the
end-link loose and push it out of the way. You may need to
compress the suspension slightly with a floor jack in order to get the
end link loose. Push it out of the way.
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A closer shot of the swaybar
end link. The 16 mm wrench is placed BEHIND the bracket to keep
the stud from rotating while the socket is used to remove the nut. |
Spray WD-40 or other lubricant
on the lower part of the strut so it will be easier to slide out of the
knuckle. Be careful not to wash away your alignment marks!
Grab the steering knuckle and
pull it down as far as you can. Your instinct will be to try to
turn the knuckle side to side, but it is held firmly in place by the
control arm and can't turn. Instead, grab the strut housing and
turn the strut side to side while you pull down on the knuckle.
This is where it helps to have a second person.
Pull it down far enough that
you can access the four bolts holding the bearing/hub assembly in place.
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This is a view from behind. The knuckle has been pulled down so the strut
is no longer blocking access to the upper two bolts. Be careful not to
damage the ABS sensor wire.
An air wrench is helpful
to remove these bolts, since the factory used a thread locking compound
and the bolts are very long. You'll be sweating if you have to
remove these bolts by hand. Depending on the age of these bolts,
you may have to fight them with a breaker bar. They do not want to
come willingly!
Discard the bolts after
removal. They should be replaced. Note the orientation of
the bearing assembly.
Install the new bearing
assembly
in the same orientation as the one you just
removed using four new bolts. It only fits in one
direction because the bolt holes are not spaced evenly. The
new bolts come with dry Loctite already applied. If you find
yourself reusing the old bolts (not recommended), apply thread
locking compound. Tighten each bolt to 75 lb-ft.
After pushing the knuckle back
up, make sure the marks on the strut align with the marks on the
knuckle. Use a floor jack to compress the suspension, but be
careful not to lift the car off the jack stand.
Position the lower control arm
back into the chassis bracket and slide the original bolt through and
attach the nut. Don't tighten yet until the suspension is
compressed in the next step. The chassis bushing will be damaged
if you tighten this fastener while the suspension is in full droop.
Compress the suspension with a
floor jack until the car is just about to lift off the jackstand.
Torque the lower control arm bolt to 60 lb-ft.
Install a new pinch bolt and nut and
torque to 50 lb-ft. Don't forget to reinstall the bracket, which is held
in place by the pinch bolt.
Insert the stud from the sway
bar end link into the bracket and tighten, using a 16mm wrench to keep
it from rotating, while you tighten the nut to 30 lb-ft.
Congratulations! You've just
changed your own wheel bearings.
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