Is this news to anyone? It's been a problem for a while.
Mine failed on my 98 ml320 around 48,000 miles. It scored the timing chain cover... but thankfully did not cut through.
My local mechanic busted his ass to get the nut off.
He completed the job and charged me $250.
I cringe to think what would have happened if my wife was driving and was far from home. She would have continued to drive, not knowing what catastropic damage she was doing to the engine, not to mention the danger she was putting herself and our child in!
Mercedes should be ashamed. I still have that balancer in a plastic bag! Just tell me where to send it, and I'll include a note to tell Mercedes WHERE TO PUT IT.