Play In Rack-And-Pinion Steering
Topic number

LI46.20-P-071904

Version

1

Function group

46.20 Steering gear

Date

10-30-2020

Validity

All passenger cars with rack-and-pinion steering

Reason for change

Various model series added (167/213/238/257/253 etc.)

Reason for block

Complaint:

TÜV (Technical Inspection Association) and/or MB workshops complain about too much play in the rack-and-pinion
steering, but are using an unsuitable testing method.

===============================================================================================
For this reason when checking the play in the steering gear, please only use the method described below.
All other methods are unsuitable for evaluating play in the rack-and-pinion steering system, which effects the steering
and driving response of the vehicle, and can therefore lead to incorrect evaluations.
Please inform the personnel at the test organizations accordingly when vehicle tests are carried out in accordance
with §29.

===============================================================================================

Attachments
File

Description

Bild Spielprufung Zahnstangenlenkung alle BR.pdf

Steering gear, design

Cause:

Unauthorized method for checking play and/or incorrect evaluation!
==============================================
Radial movement at the input shaft or at the rack on the left and right is evaluated as play.

===============================================================================================
Radial movements applied via the steering coupling at the input of the control shaft (see Fig. 2, item 1) are not relevant for evaluating play.
Any radial movement that can be felt should not be evaluated as play in the steering gear. This does not have any influence on the operation of the rack-and-pinion steering system, on the play in the steering system or on the driving
dynamics of the vehicle. The same applies to radial movements at the rack/tie rods (see figure 2, item 2), especially
when the wheels are turned all the way to one side. The steering rack in this case is extended on one side and provides an even larger lever arm to detect supposed play (method for checking play of outer and inner joints as before).
Radial movement felt when a force is applied is normal and occurs as a result of the design of the steering system.

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© Copyright Mercedes-Benz AG

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NOTE:
When the steering wheel is turned quickly to the left/right when the vehicle is stationary, particularly without power assistance, a loud clicking noise may be heard. This also occurs because of the design of the steering system and does
NOT indicate any kind of play.

Remedy:

Play test as per Mercedes-Benz specification
=======================================
Prerequisite: The steering column and the outer and inner joints of the tie rods must be free of play.
The play check on the rack-and-pinion steering itself must only be performed
- With the vehicle stationary
- With the engine running (power steering assistance must be operable)
- With the front wheels in the straight-ahead position must be performed.
The steering wheel must be turned slowly while watching the rims move.
The rims must follow the steering movement at the latest after a travel of approx. +/- 12 mm at the circumference of
the steering wheel, while the force at the steering wheel increases steadily. This "delay" in reaction is a result of the
elasticity of the steering system (steering connections, etc.) and is not a fault.
Only the axle path of the steering rack in the housing is relevant when evaluating the play in a rack-and-pinion steering system and only this path must be taken into account, as is the case with the test described above, see Fig. item
1, green arrow.
Remark: All other contrary publications on this subject are hereby invalid and will be revised with the next update.

Symptoms
Chassis/suspension / Steering system / Function / Too much play/clearance

Operation numbers/damage codes
Op. no.

Operation text

Time

Damage
code

Note

46481 17

Validity
Vehicle

Engine

Transmission

A (168)

*

*

A (169)

*

*

A (176)

*

*

A (177)

*

*

AMG (298)

*

*

AMG GT (190)

*

*

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B (242, 246)

*

*

B (245)

*

*

B (247)

*

*

C (203)

*

*

C (204)

*

*

C (205)

*

*

CL (215)

*

*

CL (216)

*

*

CLA (117)

*

*

CLA (118)

*

*

CLK (209)

*

*

CLS (218)

*

*

CLS (219)

*

*

CLS (257)

*

*

E (207)

*

*

E (210)

*

*

E (211)

*

*

E (212)

*

*

E (213)

*

*

E (238)

*

*

EQC (293)

*

*

GLA (156)

*

*

GLC (253)

*

*

GLE (167)

*

*

GLE (292)

*

*

GLK (204)

*

*

GLS (167)

*

*

M (163)

*

*

M (164)

*

*

M/GLE (166)

*

*

R (251)

*

*

S (220)

*

*

S (221)

*

*

S (222)

*

*

S (223)

*

*

SL (230)

*

*

SL (231)

*

*

SLK (171)

*

*

SLK/SLC 172

*

*

SLS (197)

*

*

X 290 AMG

*

*

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