That chain was really the only major downfall of the V8 engines in the W126 models, even the 380SE model. That was exactly why I sold my 1985 380SE. I loved the car, but the date/mileage of the last timing chain/tensioner/rails/guides was unknown, so I sold it. It was too old and had too many miles to sink hundreds of dollars into for this repair, especially since I had developed an occasional stalling, which I was informed was bad injector seals.

Too bad MB did not make these "non-interference" engines, or have designed the engine to have not had the "crumbly with age" rails. I think alot of that junk could have been eliminated. Take Lexus for instance... from 1990-97, the 4.0L V8 was a non-interference engine. If the timing belt was to break, no engine damage would occur. I had a 90' LS400 with 252K and AFAIK, it still had the original timing belt - engine was still super smooth and quiet and very powerful. I would have to look down @ the tach to see if the engine was still running, it was so quiet.

However, in 1998, they (Lexus) switched to a VVt-i engine, which was an interference engine, as was the 4.7L V8 in my old Toyota Tundra truck. Why they did that, I have no idea. I mean, why unnecessarily add risk of major engine damage if its not necessary?

To the guy that also has the SD models... unfortunately, from what I have heard, these cars have interference engines as well. If something in there breaks, the engine is likely ruined.

Good luck!