Suspension - Front Suspension Cracking/Rubbing Noise
42 Light cracking or rubbing noises from suspension strut when steering
40 10 10
2021771/2
September 10, 2010
Supersedes Technical Service Bulletin Group 40 number 10-05 dated April 23, 2010 for reasons listed below.
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AFFECTED VEHICLE
CONDITION
Light cracking or rubbing noises when steering.
^ The noise emanates from the front suspension strut mounting.
^ The complaint occurs most often when maneuvering.
^ The noise is not caused by extreme load on only one suspension strut.
TECHNICAL BACKGROUND
Possible cause #1: This is the most frequent cause. The shock absorber buffer can chafe the cap of the suspension strut tube when steering. (See
TSB 2021724.)
Possible cause #2: The boot is incorrectly fastened or deformed.
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Possible cause #3: The coil spring is not correctly positioned on the stop of the spring retainer (Figures 1 and 2).
Possible cause #4: The coil spring has a burr on the lower end. This can cause noises in the lower spring retainer
Possible cause #5 (only applicable to Audi TT with S-line running gear MY 2008 up to chassis number TRU___8J 8 1 027428):
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Incorrect dimensions of the lower spring eye. As a result, the spring does not correctly rest on the spring retainer. See abrasion in Figure 4.
Possible cause #6: Overloaded axial deep-groove ball bearing because of increased forces due to unfavorable tolerances. An indication for this
cause is that the suspension strut mounting cannot be turned against the suspension strut (shock absorber/spring). This check must be performed with
suspension strut removed.
PRODUCTION SOLUTION
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SERVICE
1. Locate the suspension strut by detaching the track rods on one side.
If the noise now only occurs when maneuvering slowly backwards and uphill with large steering wheel turn, it is caused by the extreme load on only
one suspension strut. In this case, do not repair as this is considered normal and this TSB does not apply.
2. The remaining steps address each potential cause. Check to see if the noise is gone after performing each step.
a. To address cause #1: Follow the procedure in TSB 2021724 to lubricate the bump stop.
b. To address cause #2: Correctly install the boot on the upper mountings and on the lower damper.
c. To address cause #3: Turn the spring with a clamp until the lower spring end rests on the stop.
d. To address cause #4: Remove the burrs on both spring ends and protect the chafing mark for corrosion. The spring should now correctly touch
the stop of the spring retainer.
e. To address cause #5 if vehicle is an Audi TT with S-line running gear MY 2008 up to chassis number TRU____ 8J 8 1 027428): Replace the
coil springs on both sides.
f. To address cause #6: If points a - e do not remove the noise, replace the spring, the suspension strut mounting and the axial deep-groove ball
bearing. Remove the burrs on both spring ends and protect the chafing mark against corrosion.
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Warranty
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
