WARNING: This page is about a different car, the 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Determining Circlip Fit
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Determine and install thickest circlip which can be inserted.
Determine circlip as accurately as possible using chart. Part numbers: