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  #16  
Old 11-28-2014, 12:12 AM
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Originally Posted by leathermang View Post
Why am I the only one that posts any warnings about needing a hard to find 300 FLYWHEEL to do this properly.... many folks who have used the 240 flywheel have admitted to having vibrations which they can not get rid of ....
All you need to do is match balance the 240 flywheel to the driven plate on the 617, and you are good to go. I have done several of these conversions without vibration problems simply by following this step.

You have to do the exact same thing with the 300d flywheel anyway. Both have to be matched balanced no matter where you source the flywheel. 240 flywheels are easier to find.

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  #17  
Old 11-28-2014, 12:15 AM
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Originally Posted by leathermang View Post
I believe you are taking a little liberty in stating that as a fact ... probably based on the fact that many people or mechanics do not manage to match up replacement flywheels correctly ... even when dealing with a five cylinder to five cylinder situation.... The original 5 cylinder flywheels are dynamically balanced on the engine.... and there are instructions as to matching to that one.. which is often not followed... many thinking that neutral balanced with do... thus a wide range of situations exists decades away from the original engine leaving the factory...
I found a big flywheel imbalanced the car was nearly undrivable. I blew it on match balancing an adapted gm flywheel which is a heck of a lot bigger disc, though the same weight, and it just about shook the drivetrain out of the vehicle.
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  #18  
Old 11-28-2014, 08:58 AM
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Originally Posted by JB3 View Post
All you need to do is match balance the 240 flywheel to the driven plate on the 617, and you are good to go.....
I am going on the record stating that I do not believe that.
The rotating mass inside the engine is clearly more on the five cylinder than the four... Mercedes engineers do not do things on whim... they have millions of dollars in research and development and would not put the heavier one on the five cylinder if substituting another one was as easy as you claim.
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  #19  
Old 11-28-2014, 09:18 AM
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Originally Posted by leathermang View Post
I am going on the record stating that I do not believe that.
The rotating mass inside the engine is clearly more on the five cylinder than the four... Mercedes engineers do not do things on whim... they have millions of dollars in research and development and would not put the heavier one on the five cylinder if substituting another one was as easy as you claim.
It is as easy as understanding why they did something and compensating for it.

For example, we know they made up internal balance on flywheels and driven plates on an unknown number of 617s. Whether you have a 28 or 38lb flywheel, you need to know if they did this on your application.

To compensate, you mark crank to original driven plate, and have your 28 OR 38 lb flywheel match balanced to what was on there. I have come across two 617s that have a biased driven plate balance of a few grams off. It doesnt matter if they put a 100lb flywheel on there or 2lb, if the biased balance isnt matched, you will have vibration.

Once that is done, your new flywheel has the same specific balance built in from the factory.

The benz engineers put a 10lb heavier flywheel on the 617s because the heavier the flywheel, the smoother the power transfer and the easier to shift, but on the other hand, the greater the accel loss, and the slower the takeoff. Since these were slow diesel luxury cars, i absolutely see the motivation towards smooth power application vs performance.

Lightening flywheels is a very common performance mod in many circles. I dont consider a 28lb flywheel light, but at 10lbs less than to 38lb, it makes the performance slightly peppier. If the biased balance is retained (IF the engine had it), then you shouldnt have any problems.

Personally i had no vibration issues and no problem with a 28lb flywheel. What was slightly surprising for me, was compensating for turbo lag when it kicks in in how i held throttle position. The car would take off a few seconds in gear, great fun.
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  #20  
Old 11-28-2014, 09:51 AM
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Originally Posted by JB3 View Post
It is as easy as understanding why they did something and compensating for it.

For example, we know they made up internal balance on flywheels and driven plates on an unknown number of 617s. Whether you have a 28 or 38lb flywheel, you need to know if they did this on your application.

To compensate, you mark crank to original driven plate, and have your 28 OR 38 lb flywheel match balanced to what was on there. I have come across two 617s that have a biased driven plate balance of a few grams off. It doesnt matter if they put a 100lb flywheel on there or 2lb, if the biased balance isnt matched, you will have vibration.

Once that is done, your new flywheel has the same specific balance built in from the factory....
What are you describing as ' match balancing' procedure ?
Using the rod ... much like balancing a lawn mower blade... where you spin it and mark what part comes to rest at the bottom ... while bolted to the other flywheel ?.. then keep taking off small amounts to where it does not try to stop at any particular place ?
OR do you have access to a machine ... like the new tire balancing machines... to show how much to take off where... to get what you are looking for ?
Most of us can not find a mechanic we can afford AND TRUST just to do regular stuff on our cars.... So I still say it is best to do whatever is necessary to find the 300 flywheel to start off with.... then try ... perhaps with trial and error ( pull manual trans and try different flywheel location )... to get rid of any vibrations which might be present...
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  #21  
Old 11-28-2014, 10:00 AM
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Originally Posted by leathermang View Post
What are you describing as ' match balancing' procedure ?
Using the rod ... much like balancing a lawn mower blade... where you spin it and mark what part comes to rest at the bottom ... while bolted to the other flywheel ?.. then keep taking off small amounts to where it does not try to stop at any particular place ?
OR do you have access to a machine ... like the new tire balancing machines... to show how much to take off where... to get what you are looking for ?
Most of us can not find a mechanic we can afford AND TRUST just to do regular stuff on our cars.... So I still say it is best to do whatever is necessary to find the 300 flywheel to start off with.... then try ... perhaps with trial and error ( pull manual trans and try different flywheel location )... to get rid of any vibrations which might be present...
Its a common machine shop job. You provide them with two flywheels and they can match balance them on machines. Ive paid between 30 and 150 bucks for the procedure depending on regional location.

The 38lb flywheel off a 300d is not a bolt on answer. You still have to match balance that. Any shop than can do a neutral balance can do a match balance
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  #22  
Old 11-28-2014, 10:09 AM
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Can you ' match ' balance on a mandrel the larger and smaller flywheels ...to each other ?
If you start with a 300 flywheel you can keep taking it off and reinstalling to try to find a place where it does not vibrate ( too bad )......
MOST people trying this swap.... only have the auto trans torque converter and the 240 flywheel in their hands.... how do those people proceed ?
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  #23  
Old 11-28-2014, 10:49 AM
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Originally Posted by leathermang View Post
Can you ' match ' balance on a mandrel the larger and smaller flywheels ...to each other ?
If you start with a 300 flywheel you can keep taking it off and reinstalling to try to find a place where it does not vibrate ( too bad )......
MOST people trying this swap.... only have the auto trans torque converter and the 240 flywheel in their hands.... how do those people proceed ?

Im not sure how the machine shop does the job, there is some trial and error from what I understand. Ive been told a couple times but always forget

If you simply bolt on a new flywheel you have potentially 12 positions until you get it right. Thats a heck of a lot of work with the car having to be drivable between every position so you can see if the vibration exists or not.

Makes way more sense to mark the crank to the existing automatic flywheel (driven plate), and drop off the driven plate and manual flywheel at a machine shop. You do not need to provide the torque converter.

Here is a pic in one of my swaps that shows a 38lb flywheel below a driven plate after they were match balanced. The machinist said the driven plate was a few grams weighted, so he duplicated the weighted side on the 38lb flywheel for me. This was a 1979 300SD 617.




Here is a video of a driven plate out of a 1983 300D 617 that shows a definite heavy spot. (I was trying to figure out why the thing was undrivable in a swap application). My problem is the stock flywheel was weighted, AND my replacement flywheel was weighted, and I got the bias completely off making a horrendous vibration.

https://www.youtube.com/watch?v=QAX6FiShQjQ


For what its worth, ive come across this phenomena twice personally out of 4 conversions so im at 50%, but people have done a bunch of conversions and not encountered this at all. My take is that its worth it to be sure, if its a neutral balance, thats great, and if it wasnt, at least you made sure.

I have never come across this on a 240 616 though. I think it is a 617 quirk. The number one thing is you have to mark the crank to the driven plate before you move it, otherwise you are in for the 12 position nightmare, which is not practical at all. My one complaint with mercedes about this is why isnt the crank bolt pattern asymmetrical so you can only put a flywheel on one way? plenty of other manufacturers do this, and it eliminates the entire possibility of losing your reference point
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  #24  
Old 11-28-2014, 12:19 PM
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"I believe you are taking a little liberty in stating that as a fact ..." by Leathermang. No I don't think so. Any piston engine that is solidly connected to the drive line via a clutch disc will show some "vibes" at critical engine speeds. Those vibes are vibrations sent through the body as the end result of the explosion which takes place in the cylinder. On some cars they are very hard to detect even with a manual transmission. The V-16 Cadillac of the 1930's was one such car. The 1936 Cadillac V-12 also and I learned to drive on that car. The 617 Turbo engine used in the W123 cars that we are taking about is about as far from that kind of inherent smoothness that we can imagine. And from an Engineering and Sales point of view, an engine like that will not make a happy owner unless it has an automatic transmission. The oil in the torque convertor will totally eliminate those vibes. And I suspect that reason is a number one reason why the 300D was not sold in North America with a manual transmission. It was available in the rest of the world with a manual transmission.
So my 617 Turbo in my 240D sedan does produce these vibes. This is most notable at 2700 to 3000 rpms. This does not show up in 1st or 2nd gear, it is detectable in 3rd and most noticeable in 4th.. This is not a flywheel balance issue. I can run that engine with the transmission in neutral to the red line and it is smooth as silk. This is simply the result of those large (and infrequent) power pulses booming down that 3" exhaust and being quite close to sheet metal. And it is my opinion that any 617T with a manual transmission will have some vibes. Yes the heavier flywheel will minimize the buzz, but it won't get rid of it. I had mine out for a ride this week. I just love the crisp response of that engine which is the same engine I had with the automatic. Then it was a dog and not a pleasure to drive. Now in cold weather with all the windows up and tight, I get really no vibes either. However they are there, but with everything buttoned up you just can't hear/feel them. It probably is a number one reason to really redo the A/C and then keep the windows closed all the time. But I like the fresh air and the open windows and sunroof, so I don't think I will bother.
Now if you are contemplating this transmission swap, it is really a winner. It is not easy, really it is a lot of work. And I would recommend only doing it on a very good car, clean with no rust and a really good engine. And if you have a heavy flywheel available, use it. I personally would not pay a dime for the heavy one, but it will be a little less prone to the buzz, but it won't be as fun to drive. There are a few heavy flywheels around, but they are very scarce and expensive as they only show up in cars that were imported from Europe.
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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,
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  #25  
Old 11-28-2014, 12:24 PM
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Does the 300 NA with a manual have a 38# flywheel on it?
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  #26  
Old 11-28-2014, 12:32 PM
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Originally Posted by Lucas View Post
Does the 300 NA with a manual have a 38# flywheel on it?
Yes it sure does and the only other way to get one is to get it from Europe, and it is very expensive.
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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!
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  #27  
Old 11-28-2014, 01:19 PM
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One about machining one? I have cheap access. I don't think this is hijacking. Not sure. Lol.
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  #28  
Old 11-28-2014, 02:55 PM
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Yes you could do that quite easily and machine for a shrink fit like they put the rims on the locomotives of yesterday. But I do think you might have a job finding a shop with a lathe that has jaws big enough to chuck up a ring of that size. I don't know, maybe easier then I think it is, maybe.
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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!
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  #29  
Old 11-28-2014, 04:24 PM
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"" This is not a flywheel balance issue. ""


While it is possible to introduce vibrations by not matching the flywheels... I think you are correct that your
vibes are not a flywheel balance issue...

Since I have the paper manuals and at one time just sat down and read them... I remember something being mentioned downstream in the power line which had to do with dampening vibration.. which most people were not doing or even knew about... MB paper manuals have stuff spread around in places you would not think applied to the chapter they are found in.... and it was about ten years ago when I read it.. but if you look for it you may be able to take out those non flywheel vibrations.

I think you have done a good job of being honest about the pros and cons on this swap.... so that people who want to do it have an idea of possible drawbacks...
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  #30  
Old 11-28-2014, 05:37 PM
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Thanks Leathermang, I agree 100%. The swap is really worth while, but I think some of the guys are going into it blind. You know, I have a front drive shaft piece which I got from TW which has one of those vibration dampers built onto the front end of it. It is broken but it looks like a wheel which was attached with three heavy rubber spokes. And that is just what that wheel is meant to do, absorb more of those harsh cylinder loads which are produced under full throttle at max torque. I have "ground" off the remains of those three spokes and do plan to use this piece in place of my modified shaft. I suspect the wheel part is only available with the whole shaft and the price is probably out of sight.

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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!
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