Timing Chain Kit. Timing Belt Kit. Variable Valve Timing. 2000 2001 2002 2003 2004 Audi A4 and Audi A6 with 3.0L V6 5V AVK or BBK series of engines. VW Polo Diesel. Audi A6 with engine Z15L TDI. Long Pin locating the crankshaft at TDC (Top Dead center) when timing the engine or servicing the timing belt or flywheel/drive plate.