Grinding noises from area of front axle - wheel bearing malfunctioning
Topic number

LI33.20-P-047117

Version

6

Design group

33.20 Wheel location, wheel hub

Date

02-28-2013

Validity

Model 204 except 4MATIC; except AMG; except 204.9##
(GLK), 207

Reason for change

Fixed error in title.

Reason for block

Complaint:

Grinding noises from area of front axle - wheel bearing malfunctioning

Cause:

Corrosion spreading under wheel hub sealing ring. Dirt and water are washed in front of the sealing ring of the wheel
hub via the rpm sensor bore in the steering knuckle or through corresponding gaps between the anchor plate and
steering knuckle. Corrosion forms on the contact surface of the sealing ring and spreads under the sealing lips. As a
result, moisture can penetrate the wheel bearing and cause corrosion.

Remedy:

Please note the revised procedure for repair in the case of wheel bearing damage on the front axle!
The most important new feature of the repair method is the use of a repair hub (Figure A) with inserted stainless steel
race (1).
The stainless steel race (1) is pressed onto the corroded steering knuckle (Figure D) during assembly of the wheel
hub and guarantees the new seal with the wheel hub sealing ring. This means that it is no longer necessary to replace
the steering knuckle!
Axle alignment is not necessary with this repair method!
In order to avoid follow-up repairs, always replace both wheel bearings on the front axle in problem vehicles!
First-time installation of a repair wheel hub:
1.) Detach wheel hub, bearing and brake cover plate.
2.) Use a wire brush to remove loose corrosion from the contact surface of the wheel hub sealing ring (Figure C).
3.) Clean steering knuckle spindle thoroughly.
4.) Install new brake cover plate (Figure E) with optimized circumferential gasket (picture 2).
5.) Push on repair hub (Figure A) without tilting it and pull as far as the stop with the clamp nut (Figures G,H,I)
6.) Adjust wheel bearing play (Figure J).
7.) Install circumferential gasket (Figure F) on rpm sensor.
8.) Reassemble the vehicle.
Important note for subsequent reinstallation of a repair wheel hub:
When the repair hub with stainless steel race is installed, the stainless steel race is positively pressed onto the steering knuckle (Figure D).
If the wheel hub is subsequently removed/reinstalled, there is a risk of damaging the sealing lip of the wheel hub sealing ring when pushing on.
For this case there is a repair kit (Figure B), consisting of a wheel hub sealing ring with preinstalled stainless steel
race.
This repair kit must be pulled into the wheel hub which is to be reinstalled.
02-28-2013 9:35 PM
© Copyright Daimler AG

GKRZYZA

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To do this, use the regular tool W203 589 0243 00, but with a different method.
As the stainless steel race reduces the inside diameter of the hub sealing ring, the tool die (Figures M, N, picture 4)
must be turned through 180° so that the hub sealing ring contacts the rear face of the tool die (the side not lined with
rubber).
1.) Insert wheel hub sealing ring with stainless steel race into wheel hub by hand. This centers the hub and makes it
easier to pull in with the tool.
2.) Pull in wheel hub sealing ring with stainless steel race using rear face of tool die of special tool W203 589 0243 00.
3.) Remove old stainless steel race from steering knuckle (as shown in Figures K, L).
4.) Push on wheel hub without tilting it and pull as far as the stop with the clamp nut.
6.) Adjust wheel bearing play.
7.) Reassemble the vehicle.
Note:This new repair method will soon (expected as of Week 19/2010) also be available in SDmedia

Attachments
File

Designation

Anhang.pdf

Attachment

Symptoms
Chassis/suspension / Chassis, noises / Humming/droning/throbbing
Chassis/suspension / Chassis, noises / Howling
Chassis/suspension / Axles / Front axle / Front axle, noise / Squeaking

Parts
Part number

ES1 ES2 Designation

Quantity Note

EPC Other
make
part

A2044202544

Brake cover plate, left

1

Improved rigidity to prevent
cracking

X

A2044202644

Brake cover plate, right

1

Improved rigidity to prevent
cracking

X

A 204 335 00 80

Circumferential gasket for rpm 2
sensor

Circumferential gaskets are
available with and without white adhesive foil. If the adhesive foil is present, it must be installed on the cable side (Figure E6).

X

Wheel bearing grease

1

Order with quantity index 10!
A 002 989 00 51 10

X

A2204230071

Bolt, brake cover plate

6

X

A2043300625

Repair wheel hub

2

X

A 204 330 00 60

Repair kit, wheel hub sealing
ring with stainless steel race

1

A 002 989 00 51

10

As required

X

WIS-References
Document number
02-28-2013 9:35 PM
© Copyright Daimler AG

Title

Note
GKRZYZA

Allocation

Page 2/3

AR33.20-P-0310cw

Remove/install front wheel
hub

Remedy

AR42.30-P-0712cw

Remove/install left or right
front rpm sensor

Remedy

AR33.20-P-0310-03SX

Install radial sealing ring in
front wheel hub

Remedy

Validity
Vehicle

Engine

Transmission

204.002

*

*

204.003

*

*

204.006

*

*

204.007

*

*

204.008

*

*

204.022

*

*

204.041

*

*

204.044

*

*

204.045

*

*

204.046

*

*

204.047

*

*

204.052

*

*

204.054

*

*

204.056

*

*

204.065

*

*

204.202

*

*

204.203

*

*

204.207

*

*

204.208

*

*

204.222

*

*

204.241

*

*

204.245

*

*

204.246

*

*

204.247

*

*

204.252

*

*

204.254

*

*

204.256

*

*

207.303

*

*

207.322

*

*

207.347

*

*

207.356

*

*

207.357

*

*

207.372

*

*

02-28-2013 9:35 PM
© Copyright Daimler AG

GKRZYZA

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