Quote:
Originally Posted by leathermang
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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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