I am new to this site. I am actually a big fan of Mercedes and after working on my wifes 02 A6 Quattro I am becoming even more so. We have owned the car for about 2 years now, purchased with just under 100k miles. It has leaked oil from the valve covers ever since we bought the car and I have always intended to fix but haven't had the time. I have now been forced to take the time.

The car developed a ticking noise from the leftbank a while back. Long storey short, I'm elbows deep now and need some help. I found a wiped cam lobe on what I would call #4 cylinder exhaust. It appears the the car had a cam belt changed prior to my purchase as the belt is a Continental and I think that is not the original. it also looks pretty new. I also found what appears to be hammer marks on the upper front corner of the left head almost like someone was trying to hammer on the intake cam gear and missed with a few swings. Anyway, i purchased a set of aftermarket cam holding tools "crabs" and have followed all the information I can find on the subject but cannot get both tools completely on the cams. It's almost as if the right side intake cam is off be a tooth or two.

My question is can I trust that the aftermarket tools are correctly machined or should I assume that the hamer mechanic screwed up?

Any help would be appreciated.