WARNING: This page is about a different car, the 2009 Mercedes-Benz CLK350 and 2008 Mercedes-Benz CLK350. However, it is still accessible from the selected car via links, so may be relevant.
FG 05/Set B
ENGINE 272/979, 273
Use:
Assembly link for connecting the repair chain with the installed chain when changing the timing chain.
NOTE:
Assembly links must not be left in the engine.
Fig 1: Identifying Assembly Link (272 589 03 63 00)