I have a 2008 Audi A6. Audi states that the timing chain needs to be replaced at 110,000. My vehicle currently has 108.000. I have been told that the entire engine needs to be pulled in order to replace the timing chains (told there are four in total, main, two auxiliary and the water pump). I have been told this will cost thousands of dollars. I have been told to only change the two auxiliary chains. Any feedback as to what is best?

Thanks!

James