Sucks you are having trouble, but understand the people here ARE speaking from experience.

sorry you are getting frustrated.

the match balancing is detailed in the fsm.

you can check the individual fws for balance. if you get lucky they both may well be neutrally balanced. if so you just bolt them up and go. doesnt matter which way you bolt it on.

if one of them is not neutral, the new one must be made to match the one that came off the motor.

see the fsm in this case.

if you have further questions please feel free to pm me or call.

tom w

Don't mess with a machine shop. Look for a good racing shop or race team operated shop.

The theory for match balancing is like this:

Take the two flywheels, or flywheel and flexplate, and bolt each one to a flange on the end of a short and straight pipe so that they are 180 degrees apart.

Now, if they are neutral balanced already, when you put this assembly on two straight rails it won't go anywhere. If one or both is not neutral balanced, it will want to roll one way or the other.

What you do in that case is drill holes around the perimeter of the flywheel you are going to use so that the assembly doesn't roll. Beware the "shaving a poodle" effect and drilling holes that are too big. When you get it to stop rolling, the new flywheel is match-balanced to the old.

Ted

Success at last
 

Seems the 240d flywheel was not neutral balance, and of course the flexplate wasn't. I had taken two days off from work and drove like mad mileage going from "talk to this person, bring it out and we'll look" blah blah...
After finally finding a VERY PRIVATE RACING SHOP which happen to have an sd on fumigation I had found someone who could do it and happened to be a benz fan whoa!!!...This swap seems to be greatly dependant upon your location and the shops ability around you, or lack of lol. Please keep in mind that while doing the swap it is very important to source the correct people that are not blinded by the three pointed star. They will say they can do it but when they see its a mercedes they WON'T TOUCH IT. Now we are onto the driveshaft issue LOL, first shop say's "yea we can cut 4" out no problem" (btw: is 4" correct?), but when I arrived with the driveshaft......."uhhh thats a metric shaft and we can't cut it" wtf!!! here we go...So whats the deal with cutting this shaft, the front part correct? THNX!!!!!!!! I'm now only 4" away from a complete swap...

front shaft only sounds correct. if nobody can tell you the exact length to shorten i suppose i can measure the bore center spacing and that should be the amount it is longer.

does this sound correct? this would be true if the motor mount arms are identical in the 240 and 300.

tom w

I'm using the original 240d mounts, instead of anything else...I'm aware of no engine shocks, but this engine is so smooth guys it doesn't vibrate at all!!!!!!
So im not to worried about them yet...

4" is correct.

Here is a good example of a non-neutrally balanced manual flywheel. Notice the drill holes on the right.

Its a rainy day and Car Talk is on so I went out to my shop and examined two F/Ws, one from a "77" 240D and it has "balance " holes and no witnes mark, the other is from a "78" 240D, same thing except the holes are drilled in the Inner service where the pressure plate bolts.

Just because there are holes does not mean it is not neutral-balance. The holes may have been put there to bring it in to neutral balance. With that many holes it's not likely, but possible.

The point is don't assume that if there are no holes that it is neutral balance...

Ted

that is correct.

tom w

Any more luck Kraut? Be sure to take some pictures while you are doing the swap. :D What is it costing to have the components modified?

How bad is it to combine the vacuum and electrical systems? I think at first I will stick with the stock 240 gauges and rear, then play with it more as I have more time. I think I am going to attempt this over my week off around thanksgiving, so I have plenty of time to plan and research. Any more advice on adding the second set of engine mounts? I don't think I am going to be able to have the donor car nearby, anybody have suggestions of other parts to grab off of the donor while it is convenient? Thank you.

second set of engine mounts????

tom w

Neutral Balancing
 

If any Mercedes engine left the factory with a perfectly neutral balance on the flywheel it was just shear luck and I wouldn't bet on finding one. As detailed in the service manual the engines are balanced as an assembly with the two balancing planes being the balancer and the flywheel.

I have had these balanced by a local shop and they had no trouble doing it. They do alot of racing engines and such so they are used to out of the box stuff. The key is probably finding a shop used to doing out of the ordinary stuff.