I'm stuck on my 603 head-pulling job. Used the bolt and washer trick to pull the upper chain guide pin--worked just fine.

The bottom one is a bear. On the first try, I stripped the threads on a bolt, so threaded in a much longer and I think stronger bolt, which snapped with about 10mm protruding. Backed out the remains of the bolt.

Now I see that I should chase the threads before proceeding further--they weren't helped by these escapades--but I think my options are diminishing. The pin seems to be seated so firmly that low-strength bolts may fail if I use the same method again. So, what to do?

1. Chase the threads with a tap, find a high-strength bolt/nut combo and try again.
2. Find an impact puller as specified by Mercedes. (where to get one of those?)
3. Another option I've not considered?

I'd appreciate any ideas before I really make a mess of things.

The good news:

• No apparent cracks, based on a careful look with a mirror.
• Evidence of head gasket degradation--the likely cause of oil in the coolant.
• An undetected leak from #6 exhaust at the back end of the exhaust manifold. The car should be quieter when I'm done.

__________________
Rob