'95 E300 with 606 engine. Vacuum pump bearing came apart @ 150,000 miles but didn't destroy anything. At 200,000 miles lost vacuum but then lost timing chain, and exhaust cam. We find that the pivot arm probably broke first then engaged timing chain.
Problem is we have lower mileage but same cars in fleet, we have serious concerns about longevity of this engine with a vacuum pump design able to do so much damage. Anyone familier with such failures?

Yes, have seen problem on several occasions. Would have vacuum pump replaced on any high mileage OM606 motor.