My '83 300D (w/ 105,000 miles) harmonic balancer started throwing sparks rubbing against the water pump pulley and appeared to have walked forward. After pulling the fan and wp pulley I found the crank bolt, 3 washers and 3 small metal pieces that when combined could make a pin shape. My ac compressor made some scary noise before it happened, so I'm guessing it seized, but not sure they're related. I'd like to know what the metal pieces are and what would be the next step to getting the crank bolt back on. Any help appreciated.

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Sounds like it was not properly torqued. Torque setting is WAY up there. Don't remember exact number.

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Jim

Should I be concerned about those metal pieces? Any idea what they would be from? If all is good should I just throw some blue locktite on there and torque it down to that scary number?

That should be a 1/2 moon key. Probably have to pick it up from dealer. Should be pretty cheap.

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Jim

I believe there are one or two steel dowels that lock the balancer to the crank to keep it from slipping. You need to pull the balancer and check it's bore and the crank for damage.

Happy Motoring, Mark

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DrDKW

Checking the crank for damage is a good idea. It will be a shame a 105k engine needing a replacement crank.

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1983 123.133 California
- GreaseCar Veg System

I thought keyways were more shaped like a typical slice of watermelon. This looks different, so I'm guessing it may be a locking pin. Once I pull the balancer am I just checking the crank for damage from a freely spinning balancer? What else could happen unless the keyway is shot as well, right?

links courtesy of whunter

Diesel Harmonic Balancer threads

Main seal front/rear and harmonic balancer + Pulley

some of the answers above are speculative, there is no half moon key on the front of the crank, there ARE two dowel pins which keep the crank from spinning inside the balancing disk.

I am going through similar problems but my crankshaft bolt seems to be firmly attached. If you think you might have found pieces of a pin and the big crankshaft bolt came loose, loctite and torque are likely to be a VERY temporary fix.

Hope the links help

^

You are correct. I was thinking of the 602/603/606 engine. Sorry for the mis information.

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Jim

Thanks for the links. I now have a much better grasp of how this is put together (supposed to be). I'll pull the balancer today and hope for the best.

Torque on the main crank bolt is like 180ft/lb.

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