Mercedes: timing chain, intake cam, valve damage

Question
The sprocket on the intake cam is like a big hub that shifts back and forth about three teeth without moving the cam what position does it need to be in when installing timing chain ?

Answer
The slight rotation is probably to allow for timing degree adjustment. It is important that the sprocket is properly adjusted to avoid valve damage to the engine.

You will need a engine repair schematic for the timing chain install or consult with an independent Mercedes mechanic who is familiar with the process.
The schematic may be available at 'All Data'

http://www.benzworld.org/  
is also a  good source for technical help in their forums.
Ebay is sometime a source for used manuals.

Good Luck
Rob