And its worse than that....

When examined closely one will see that there are two dowels keying the balancer. You will note engine timing marks on the balancer, there is only ONE right position and MB would in no way allow you to do it wrong, thus the two doewls are not 180deg apart. You have to know where the motor is and whether you are on the right stroke to chose between the two positions as it isn't obvious until close observation on assembly.

That was the good part, I can tell you that there is about one chance of solving the problem without a crank repair. That would be to start with a new balancer or atleast a used one that hasn't failed. This one has failed!

A proper fitting balancer will have to be pulled onto the crank with a puller. It will have to be done carefully as the two halfs of the dowel hole must align perfectly and once a few millimeters on the thing doesn't turn relative to the crank by hand. A long heavy punch and hammer can tap out a slight misalignment as the balancer approaches proper depth. Once in position the dowels should driven into the two aligned holes with a hammer and the large bolt properly torqued.

You stand little chance of a long term repair if you can turn or install the balancer by hand. It must be snug to down right tight. We have fixed ones with too little interference by drilling two new dowels at 90 deg to the pair already there. Using a bearing/stud mount type locktite might be a last resort, used on the crank to balancer fit, not the bolt.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician