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Old 10-05-2015, 01:17 PM
Frank Reiner Frank Reiner is offline
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Join Date: Feb 2011
Location: Modesto CA
Posts: 2,847
Originally Posted by ScooterABC View Post
On the M180 engine the flywheel and crankshaft are balanced as a single unit. I think you need a flywheel for a manual transmission car but I don't know how you balance it with the crankshaft.
Originally Posted by ScooterABC View Post
An M180 flywheel is very much NOT independently balanced. It is balanced with the crankshaft. I would assume swapping flywheels is deemed "close enough". But what you can NOT do is use an M180 manual transmission flywheel on an M130 engine, since the crank and flywheel on the M130 are independently balanced. I have heard that a machine shop that rebuilds engines can balance an M180 flywheel such that it is neutral (balanced) independently by doing a lot of metal removal. That's as far as I got with it.

I doubt that an M180 flywheel has any particular value.
Re: Balancing of MB flywheels, both manual trans & auto trans

In the manufacturing process, all flywheels are neutrally balanced at the end of the machining steps. They are then delivered to engine assembly and build-up. In build-up a flywheel (and front hub) is mated to a crankshaft, and the unit is checked for balance. In many instances, but not all, metal may be removed from any part of the assembly, including the flywheel, to achieve the desired balance condition. As a consequence, many flywheels will be drilled to remove metal such that the flywheel, checked alone, will no longer be neutrally balanced. It is for this reason that Mother Benz specifies that all replacement flywheels be matched for balance/imbalance to the original condition. The shop manuals illustrate the tool that can be used, and the procedure for matching.

Edit: In the following post (#9) Scooter takes umbrage with the above statements, and correctly so. The first two engines in the M180 series, the M180 and the M127, were four-main bearing engines, the crankshafts had very little internal counter-weighting, and the flywheel and the front hub carried substantial cast-on counter weights. Going into build-up those three pieces were individually decidedly unbalanced. When combined as a unit, and given a final touch-up balance, they were then a balanced crankshaft assembly.
As described above, the M129/114/130 seven-main bearing engines have internally balanced cranks, and essentially neutral flywheels and front hubs, that are then adjusted in the final crankshaft assembly. This process is also common to the four- and five-cylinder engines.

Should anyone wish the use of the balancing tool I have one for loan or purchase.

Last edited by Frank Reiner; 10-06-2015 at 08:14 PM.
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