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Discussion Starter #1 (Edited)
Sorry, that was a joke to get this started. I pulled off the stock kit that had been on a stock truck for 6-7 months. The clutch plate was getting skinny. The plates were colored by heating to to some significant slipping. There had been some heavy towing but not extreme. I also pulled off a new stock flywheel that had been on the same truck for only two weeks. It had already started to go bad and it had to be re-indexed in order to pull it off.

I took the ring gear off an old one and also broke it apart to examine the internal components. Here are some pics and explanations.
 

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Discussion Starter #2
The first pic is of the rear half of the flywheel there are six holes where this was attached to the inter spring plates. You can see the bolt holes around the center hole for the input shaft, which usually requires re-indexing in order to remove the DMF.
 

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Discussion Starter #3 (Edited)
The second pic shows the spring plates (there are four plates rivited together, each of which is a different thickness and design) and front rivit ring which holds the spring plate to the front half of the flywheel.

There are six rivits on the spring plates which were drilled to seperate the flywheel and you can see the ends of them, they are a little shiney. There are eight larger rivits which hold the front ring on. There is half of one of these rivits laying on the rear half flywheel. These were also drilled out.

On the spring plates edge you can see eight cut outs which the front rivits went thru. Here is how they were set on the front half flywheel:
 

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Discussion Starter #4 (Edited)
The front rivit ring is a little bent due to disassembly. The four large springs have smaller springs inside them.

The DMF is made by LUK and they also make similar ones for Dodges and Fords. Those have failed as well. The purpose of this design is to absorb the low rpm/idle diesel spike described on this post:http://dieselplace.com/forum/showthread.php?t=51188

On semi trucks they have the same issue and they resolve it using a dampner balance wheel.

Without a dampner there is generally a rattle at neutral with the pedal out which makes the spike noise more noticeable. Base on another post on aftermarket, ZF indicated that the spike would not damage the ZF6. (I will be investigating current dampners made for duramaxes and can probably do distribution of any of you are interested.)

The spring plates, rivits, and the weight of the two flywheel halves just don't handle the torque of a diesel engine very long. The spikes at idle and the impact of acceleration and power loosen up these parts in some places and cram some of the parts in other areas.

Hope this post helps explain why this design is a failure.

Good Luck,
 

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That explains a lot. I'm thinking that maybe with all of the flex and movement built into that thing, at speed there gets to be a harmonic vibration that sets up and causes the flywheel to wobble (think about a quarter spun on a table, just before it lays flat) and it slip enough for output RPM's to be a couple less than input RPM's. The RPM difference creates the heat that causes "hard peddle". Maybe?
 

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WHHHAT...we got no stinking DMF problems!!

Well NOT ANY MORE!!:ro) Thanks Deadeye for posting the pics so everyone can see the pain we have been enduring with this thing!!
 

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Discussion Starter #7
Precision37;
I am sure your idea is correct. If you have a digital tach you will see that the idle or cruise rpms very by about 20 rpms at any level (unless you are accelerating?). Also, I agree that the wobble results from wear and problably does change the output rpms. The springs are supposed to absorbe the spike but it is to much power and probably causes the eight rivit notches on the spring plate to impact the rivits. Either the rivits or the spring plates cause the rattle. As to heat, I think that once the spring disc is damaged and it starts to rattle the rear half of the flywheel does not hold to the spike and causes clutch slippage. This heats up the pressure plate and flywheel causing heat. If you look at some of my SMF posts early this year you will see pics of a burned DMF plate. I don't know how high the temp gets but if it were real high (over 1100*?) I wonder if it would burn up the biodegradeable clutch plate?

The SBC feramic will handle up to 1300*F heat but I bet it will not cause hard pedal. The heat flowing to the SC either goes thru the air or transfers from the pressure plate diaphram finger springs. It is kind of hard to know exactly how this happens. But guys with another SMF have done pulling and launching and created heat but not had hard pedal. Hhowever, once the stock kit is replaced the hard pedal problem disappears!!

duramaxedout;
Thanks for the post. Hope you and Laura had a great holiday with with all your family!!

Thanks,
 
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