617 Turbo->240D 4-speed questions - PeachParts Mercedes-Benz Forum

bgkast · #1 07-25-2006, 10:08 PM

I have been reading through all of the threads on this topic I can find, and just want to make sure that I have identified all of the major steps.

1) Pull engines/transmissions
2) Have 240 flywheel balanced and use it to mate 4-speed transmission to 617 engine
3) Shorten drive shaft and shift linkages 4 inches
5) Install 617 engine with 4-speed transmission
6) Splice together electrical and vacuum systems

Some of the threads made the swap seem easy, others like a major pain. Should I expect a major headache? I am trying to decide if I want to attempt this or if I should just find a new 240 engine. Thanks –Bryan

#2 07-25-2006, 10:18 PM

Quote:

Originally Posted by bgkast

2) Have 240 flywheel balanced and use it to mate 4-speed transmission to 617 engine

Some of the threads made the swap seem easy, others like a major pain. Should I expect a major headache? I am trying to decide if I want to attempt this or if I should just find a new 240 engine. Thanks –Bryan

Balance the 240 flywheel to match the "flexplate" from the 617.

It is easy. You can ease the pain even more if you have the donor near by, just in case.

It's a good project for when you have a full weekend to devote to it.

bgkast · #3 07-25-2006, 10:37 PM

So I should put a reference mark on the flywheel, flexplate, and crank on the turbo engine, then take the flywheel and flexplate into a machine shop for matching? Thanks

#4 07-25-2006, 10:52 PM

Quote:

Originally Posted by bgkast

So I should put a reference mark on the flywheel, flexplate, and crank on the turbo engine, then take the flywheel and flexplate into a machine shop for matching? Thanks

Yes, set the 617 to #1 TDC and mark the crank/flexplate with a small punch (not an ink marker).

You don't need to know #1 TDC for the 240 flywheel. The machine shop will find the heavy point and use it as a base point to match balance.
EDIT: Also, you don't need the torque converter to balance. The TC is neutrally balanced on it's own.

t walgamuth · #5 07-25-2006, 10:55 PM

the proceedure is described in detail in the factory service manual. an easier method works when the fw is neutrally balanced. which they often are. first check the fw from the engine you want to use. if it is neutrally balanced then make sure the fw you are going to use is neutral also.

also you really should swap out the radiator, speedo and rear end as well. also a second engine shock bracket must be fabricated to do it right.

and if you can do it all in a weekend i will be impressed.

did you mention shortening the driveshaft?

it is a very worth while conversion. not without effort or expense, but you get the simplicity of the 240d with excellent performance. if you do that you will need a speedo to match.

tom w

oh and i would recommend using a 346 rear end from a na 300d to ease taking off with the four speed tranny.

bgkast · #6 07-26-2006, 12:51 AM

Guess I'll have to hunt for a Factory service manual. Does it detail the addition of the engine mounts too? I'll probably stick with the 240 rear at first. I should have a week or so to attempt it in November, so I have awhile to search for parts. The car was only $400 so I have some extra cash to play with. As for the effort, I guess I am a glutton for punishment.

Does the drive shaft need to be balanced as well?

#7 07-26-2006, 01:07 AM

Quote:

Originally Posted by bgkast

Does the drive shaft need to be balanced as well?

Yes, cutting and welding it will change it's balance. While it's out, it is the perfect time to replace the center support and bearing.

While my 240D only had 195k miles at the time, the center support rubber was completely gone. No doubt one reasons the last owner replaced most of the front end trying to fix a bad highway speed vibration.

heavyfoot · #8 03-30-2009, 01:49 PM

would any one be able to tell me if the torque converter on an automatic MB balance the 617 engine?

Thanks,

Bajaman · #9 03-30-2009, 03:03 PM

Not sure what your asking, but the 616 and 617 use the same torque converter.

#10 03-30-2009, 07:50 PM

They torque converter is always neutrally balanced by both the metal and the flow of the fluid inside the TC.

bgk202 · #11 03-30-2009, 11:42 PM

I am begining a 5spd conversion to my w115 300D. I heard a lot of feedback about match balancing so I pulled everything and had it zero (neutral) balanced.

Crank, flywheel, harmonic balancer, front crank pulley were brought to a machine shop where they were cleaned and balanced (they left the crank as-is, said it was perfectly balanced & everything else needed balancing).

There is more pics / info on my conversion at this link: http://www.peachparts.com/shopforum/diesel-discussion/248926-5-spd-conversion-begun-1975-w115-300d-post2155015.html#post2155015

Bajaman · #12 03-31-2009, 08:21 AM

I'm not sure everything is supposed to be neutral? I would think a 5cyl would need a offset somewhere.

winmutt · #13 03-31-2009, 02:49 PM

Oof, I would have just had the flywheel balanced. GL.

bgk202 · #14 03-31-2009, 03:19 PM

The machine shop said that the crank was dead-on neutral balanced by itself and the amount they removed from the other parts seems minimal. (probably due to improved balancing technology)

Does anyone know if the whole crank assembly + flywheel is supposed to be neutral balanced? If so, than all these parts, if all neutral balanced when assembled should theoretically create a neutral balanced assembly.

Isn't the point of match balancing to maintain neutral balance of the whole assembly. Has anyone ever seen a mercedes crank that was not intended to be neutral balanced? Your thoughts would be appreciated . . .

bgk202 · #15 04-01-2009, 12:56 PM

Talked to a place in California that rebuilds Mercedes motors. They said that the front pulley should be neutral balance separately, They also said that the crank assembly should be neutral balanced. However, they say that the way mercedes does it (and they do it) is to neutral balance the crank, hub (the thing with the timing marks), and flywheel as a one piece assembly.

So theoretically, if everything is zero balanced, than the assembly as a whole should be zero balanced . . .

They mentioned possible "static" balance issues. I didn't know what this meant so I looked it up: "By static balancing, one means that you insure that the crank shaft is in balance while it is stationary in any position; that is, that the shaft is actually the center of gravity when it is stationary. Put another way, there is no tendency for a static crank shaft to rotate from it own imbalanced weight." from http://answers.yahoo.com/question/index?qid=20090316165052AANKWCL . This is different from dynamic balance - i.e., balance around a central axis when the crank is spinning .

I don't think this will be an issue though since my crank was already neutral balanced and I didn't have to mess with it . . .