the distributor and the harmonic balancer need to come off before you can get to that bolt on the water pump. its a major pita. On the harmonic balance there are little bolts in there that need to be lined up and you can get them misaligned. It has to be done by feel unless you want to tear off the radiator and aux fan and ac condenser. I believe the indentation on the harmonic balancer was there on the older engines (pre 1986) but when I did the water pump on my old 420sel it was not there. It was a 1986.

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1984 300SD Orient Red/ Palomino
1989 560SEC
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