Humming noises in drivetrain in area of rear axle when cornering
Topic number

LI35.31-P-066469

Version

9

Function group

35.31 - Rear axle center assembly

Date

9/10/25

Validity

Only affects other vehicles in the production period from
04/06/2017 to approx. 06/30/2017

Reason for change

Removed 167 validity. released LI35.31-P-079734 and
LI35.25-P-077385 for 167 rear differential noises

Complaint
Possible humming noises from the drivetrain in the area of the rear axle, especially during tight cornering in the lower
speed range.

Attachments
File

Description

Glc diff.mp3

Reference file (humming noises from the rear axle differential).

Mein Film.mp4

Reference file (humming noises from the rear axle differential).

Cause
Additives in rear axle differential oil

Remedy
Note:
Please follow the instructions in this document. The replacement of components (other than those named for processing) is not effective.
Remedy:
A test drive must be performed. For accurate analysis (localization) of the noise, the "Steelman Chassis Ear" noise
diagnosis kit can be used, for example.
If the rear axle differential is unambiguously identified as the cause (noise source), the oil must be replaced. Observe
the following:
1. Warm up the oil in the differential by means of a short test drive.
2. Drain the oil from the differential and fill it with new oil according to the parts list in the attachment. Please follow the
procedure described in AR.35.31-P-0523OLC.
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© Copyright Mercedes-Benz AG

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Note: To ensure that the differential is drained as completely as possible, both rear wheels should be rotated slowly
2-3 turns while draining. Make sure that as little residual oil as possible remains in the differential.
3. Please advise the customer that in isolated cases the problem may continue to occur for another 30 to 60 miles after the oil has been replaced.
If the problem is still present after the appropriate mileage:
•
•
•

Double check the appropriate mileage was driven.
Repeat the flushing and filling procedure a second time, make sure to properly flush all the diff fluid out
If no change after the second flush and additional mileage. replace the rear diff

Disclaimer
NOTE: The information contained in this document is intended for use by trained, professional technicians with the
knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz
approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and
provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect
is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a
symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes
resulting in the same or similar symptoms or conditions described in this document, and trained professional service
technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained
in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.

Symptoms
Power transmission > Noises > Humming/droning

Parts
Part number

ES1 ES2 Designation

A0019898803

09

Quantity Note

Mobilube FE Plus NG 75W-85 ca.0,80,9l

A3529970032

Screw plug

2

A0029892371

Omnifit 100H sealant (50g)

geringe
Menge

EPC

AR.35.31-P-0523OLC, only hypoid
oils as per specification MB 239.71
are to be used (A 001 989 88 03 corresponds to Mobilube FE Plus NG
75W-85)
X
See AR.35.31-P-0523OLC

Operation numbers/damage codes
Op. no.

Operation text

Time

Damage
code

Note

350000

OIL CHANGE AT REAR AXLE DIFFERENTIAL

H

35001G6

requires separate punch

009151

ROAD TEST

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separate time punch with in/out miles

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