Flywheel/Crankshaft Balance on 230SL

[SLnoob]

I was reading an old thread from 2011 regarding this topic but there was no option to reply, so I started a new thread about this specific to the 230.

It was said that 230's had the crankshaft and flywheel balanced as a unit, while 250's and 280's were balanced separately.

I am currently converting an Auto to Manual and have a new and much heavier flywheel to mount on the crankshaft. I intend to take the crankshaft and flywheel for balancing.

I have a few questions.

Do I need to provide the main pulley for balancing as well?

Do I need to provide the pistons/rods so that the balancing shop can mock up the weights of them and balance with dummy loads on the journals?

And lastly, can anyone recommend a shop who specialises in this job.

Thanks!

[ja17]

You will need to have the crankshaft, flywheel and front vibration dampner for the crankshaft balancing. Your machine shop may not need the piston and rod assemblies for the crankshaft work. They will need the piston and rod assemblies to weigh and match them to each other. The crankshaft is "counter balanced". With a 230 series engine, the new flywheel will need to be "counter balanced" to the crankshaft and dampner.  Bring the old flywheel. They may want to match the counter balance of it. At some point, the dampner, crankshaft, and flywheel will need to be balanced as one unit. The individual parts end up being "counter balanced" against each other to achieve a balanced assembly.

Make sure the bolt pattern of the flywheels are the same.  You may need different bolts (longer) for the standard flywheel. Make sure you install a centering bearing with dust cover in the back end of the crankshaft for the standard transmission shaft. Also note speedometer cables are different for the standard shift transmission. Drive shaft front is a different length.

Hopefully the flywheel you are using is off a std. 220 or 230 series. These will have a counter balance mass already and your machine shop will have less problems.  If you are using a flywheel of a 250 or 280 series, they are balanced and do not have the mass for counter balance.

Find a good automotive machine shop in your area. Talk to the "Hot Rod" community for a qualified engine builder/ machine shop. Keep us up-to-date.

[Rick]

I find that balancers do want your pistons and rods also.

[SLnoob]

I find that balancers do want your pistons and rods also.

Yes, this is something I'd like to find out more about. I have heard of balancers mocking up the equivalent weight of the piston/rod and clamping them to the journals while doing the balancing. I'm not sure which is right. Currently, I have not found a suitable outfit who can do the job for me. I am open to suggestions on a balancer who is familiar with our engines, someone who does this model this on a regular basis.

[Rick]

I do not know what shops would be in Singapore.  In southern California I would go to Metric motors. They are the best in knowledge on mbz engines.

[SLnoob]

If need be, I will send the items out for balancing. I don't necessarily need the work to be done in Singapore. Thanks for sharing!

[SLnoob]

In southern California I would go to Metric motors. They are the best in knowledge on mbz engines.

I tried reaching out to them, it seems they are mostly geared toward selling reconditioned engines or rebuilding engines, not so much in providing balancing services. However, they said they make an exception for me. That's good news!

[Rick]

They are good people. And- they actually are experienced and really know what they are doing as compared to some shops that only will "say" they know what they are doing.

[SLnoob]

On a slightly separate note, does the propeller shaft require balancing as well. Is it something that Metric can do, or should I look for someone else (anyone to recommend).

[Rick]

Not all driveshaft shops can do a Mercedes two-piece driveshaft.  If you have lost the relation between the two driveshaft parts, you should have it balanced.  Mercedes did not mark the driveshaft relationships until 1983 and they balanced it as a unit and each half was not balanced seperately.  Probably a good time to replace the center u-joint also.  Talk to these people and see if they make sense.  I have used them.  There are others also-

Oceanside Driveshaft
2435 Industry Street, Suite B
Oceanside, CA 92054

760-439-9719