If it was my 617 and I planned to continue driving it for many more miles, I would not tighten, but I would go the route of getting that balancer off that shaft and see how much damage has been done. If all the damage is confined to those round alignment/keeper plugs you will be very lucky. If you need a new balancer, well that isn't good, but if you need a new crank, now that is serious business. We have read about so many engines that were turned into junk because of that problem. You have the radiator off now, get in there and take a look. According to the Haynes Manual, the correct torque is 244 ft/lbs.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

I have a 1976 240D (W115, OM616) with a wobbly crank pulley. The wobble is more pronounced further away from the engine. There does not appear to be much of a wobble on the part of the pulley closest to the engine.

Here is a video: https://youtu.be/Ir3YPEvKNJA

I tried tightening the allen head bolts that hold the pulley to the balancer (I think this model comes with only three of them - I did not see space for any additional bolts that may be missing). I don't think they tightened any, but I stopped to come online and read more about the issue and to avoid stripping the bolts. I may try again after cleaning the allen sockets in the bolts.

Would tightening these bolts be my first step and possibly my solution?

I don't have any space to work on the car at home (I think my neighbors may be annoyed already), so based on the video does it look like the car should not be driven? The engine is in great shape and I would not want to make matters worse. If the issue is more complicated than loose allen head bolts I probably need to get the car to the mechanic (and keep dreaming about having a garage one day).

I really appreciate all the information and advice on here.

I have a 1976 240D (W115, OM616) with a wobbly crank pulley. The wobble is more pronounced further away from the engine. There does not appear to be much of a wobble on the part of the pulley closest to the engine.

Here is a video: https://youtu.be/Ir3YPEvKNJA

I tried tightening the allen head bolts that hold the pulley to the balancer (I think this model comes with only three of them - I did not see space for any additional bolts that may be missing). I don't think they tightened any, but I stopped to come online and read more about the issue and to avoid stripping the bolts. I may try again after cleaning the allen sockets in the bolts.

Would tightening these bolts be my first step and possibly my solution?

I don't have any space to work on the car at home (I think my neighbors may be annoyed already), so based on the video does it look like the car should not be driven? The engine is in great shape and I would not want to make matters worse. If the issue is more complicated than loose allen head bolts I probably need to get the car to the mechanic (and keep dreaming about having a garage one day).

I really appreciate all the information and advice on here.

I just did belts, oil cooler hoses, and mounts on my 81 240d. Started it up and it was idling smooth, but when I looked down at the crank pulley, it looked like it was wobbling. In fact, to the naked eye, it looked like it was wobbling separate from engine motion. Made me start looking on here.

I’m sensitive to the “what could be”, regarding the pulley as it sheared off once when my ac compressor seized. Some bolts must have been loose or lost.

Anyway, found a new pro tip. Use your smartphone’s slow motion video capability. This made it pretty easy and clear. Watching real time isn’t conclusive, this to me indicates a solidly attached pulley moving in stride with the oscillations of the engine.

Hope the link works:

https://youtu.be/4m2m6jiiMSU

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

This will be my first post here (or anywhere to be honest) after years of reading and learning from you all. I cannot thank you enough. OK...so other than feeling like fresh meat in the cell block, my inquiry is relatively straight forward:
@JHZR2 what did you end up doing about the wobble. Mine is much worse and for a long time I thought it was an exhaust leak. It causes a loping or bogging sound especially at slower acceleration from being stopped, but is audible at idle and almost sounds like knocking. When you look down past the fan the thing is gyrating all sorts of funky. I will try and upload a video...slow motion sounds like a great idea JHZR2 ...thanks for the tip! Would there be any benefit to just pulling the crank bolt out and looking at it?

Go easy one me Thanks in advance,
Alex

On certain models Mercedes-Benz noted the lower pulley failed,pulley cracked
at allen bolts. The repair called for up dated,stronger pulley.

A wrecking yard pulley,by this time would most likely be good.

A long wooden stick (such as a broom handle) will give good sound results if you do not have a stethoscope.

I had my crank bolt come loose and my dowel pins sheer about 5 years ago. Here is the thread I made about it. I've had no problems since changing the dowel pins, replacing the bolt and washers and applying the correct torque to the bolt.

Not the greatest day ever. (crank pulley)

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