The UK quattro Network
The UK's mobile Audi 5-cylinder mechanic - 07833 654800, 24x7
Specialist in turbos, quattros, electrics and non-starts

Crankshaft Group - Installing the Cam Belt

28-404 The Cam Sprocket Timing Mark

If the engine has been dismantled, it should be reassembled with both the crank and camshaft set to TDC - otherwise valve or cam damage is a possibility.
The small recessed dot (occasionally a line) is set level with the top of the cam cover gasket before reassembly. If in doubt about the mark, note that the front two cam lobes (nearest the sprocket wheel) should both be pointing upwards and clear of their followers.
It is useful to apply a small dab of white paint (Tipp-Ex, Liquid Paper) to the mark to make it a little easier to see.
If the sprocket wheel has been removed, take great care that the Woodruff key remains in place during reassembly.
Pack the area below the cam sprocket with rags during reassembly in case the Woodruff key falls out.

15-504 Replacing the crank pulley and cambelt

Take care when replacing the harmonic damper and sprocket assembly that the belt does not become nicked or folded.