Faulty dual mass flywheel (KV6)?

[Blink]

My DMF is still on the car. If I rotate it by hand (as shown) it moves around 15mm before any spring resistance is felt.

Is this normal or is it faulty?



https://rimmerbros.com/Item--i-PSD103252

https://www.ebay.co.uk/itm/Dual-Mass-Flywheel-DMF-415017210-LuK-PSD103250-PSD103252-Top-Quality-Replacement-/233642717268

[COLVERT]

But that's only a fraction over 1/2 "---I'm not sure but I think that's acceptable.

There have been lots of threads with that type of question in. Shouldn't be too hard to find.---

[Blink]

I can find lots of threads about the DMF but none that give the actual specs/tolerances.

I found this from LuK (the KV6 DMF is a LuK) nut it's meaningless without the instruments.

[Number 6]

Have a look at this, It may help.https://youtu.be/P55D-xY31vQ...

[Blink]

I've already seen it John - that's what prompted me to start this thread.

[T-Cut]

There is a long-standing belief that the LUK specification for checking the spring and bearing fatigue is as follows:


There shall be no more than 30mm of free axial rotation between the masses at the periphery.
There shall be no front/rear slop between the masses.

However, these figures have on occasion been disputed, so the best suggestion I have is to go to the supplier/distributer sites and try to interpret tha data given there. If you go to the following URL, you'll see the page for the 2.0 litre KV6 DMF by LUK with the Xpart/Rimmer part number shown. Note the LUK code is 415 0172 10.


Click: https://webcat.schaeffler.com/web/sc...1&showResult=1


On the RHS of this page are six PDF documents. The lower right one gives the required data on the permitted limits of spring wear (for the want of a better word).. This is expressed in rotational degrees between the two masses rather than a circumferencial measurement. The spec is the Maximum Clearance Angle and is quoted in both degrees and as maximum number of teeth on the flywheel edge that cover this angle.


The limits for 415 0172 10 are 17 degrees or 7 teeth. (I wonder if 7 teeth is very far off the 30mm I quoted at the start?)


TC

[Blink]

Thanks for finding that TC - it looks like the info we needed.

I've condensed the document down to the relevant bits.

Explanation of symbols.



The relevant info for LuK DWF 415 0172 10 - highlighted green.



So it's:

• Number of mounting holes = 6
• Maximum sideplay = 1.6mm
• Maximum clearance angle = 17 degrees
• Number of teeth (to reach max clearance angle) = 7
• Friction control plate = no figure shown
• Pilot bearing = no figure shown

I've just tried mine again.

If I grab hold of the front ring and use all the force I can muster, I can turn it 25mm clockwise before any spring resistance is felt. I can then turn it another 5 mm under what feels to me like heavy spring resistance.

So the maximum I can turn it by hand is 30mm, with the last 5mm of that being under spring resistance.

One tooth is approximately 15mm on the first wheel. So 30mm is two teeth. Therefore I can turn it two teeth with only 5mm of spring resistance.

Does that tell us anything?

I realise that accurate instruments are needed to do this properly - for instance, the guy in this video is able to apply a lot more force than I can because he's using the right tools. I'm just doing it by hand and pushing as hard as I can (which isn't very hard at the moment 'cos I'm knackered!).

I'm on the verge of just buying this one and have done with it.

[Blink]

MGR factory fitted LuK DMFs on the KV6.
MGR Part number - PSD103252
LuK part number - 415017210

[mh007]

As the box is out & with the movement you've stated, I would replace it.


They don't fail very often but I had a ZT-T CDTi in a few years back with slave failure, no other issues such as clutch judder, clutch slippling or any untoward rattles etc from the DMF.
I did a DMF tolerance check & had around 18mm maximum movement including under tension.

I fitted a 3 part LUK clutch kit & when I got to the test drive, I didn't even get into 2nd gear when it lost all drive!
Removed the gearbox again only to find that the DMF had completely failed.
Lesson learned!!


The one in your link is a good price & I've purchased from that company before without issue.

[Blink]

Originally Posted by mh007

As the box is out & with the movement you've stated, I would replace it.


They don't fail very often but I had a ZT-T CDTi in a few years back with slave failure, no other issues such as clutch judder, clutch slippling or any untoward rattles etc from the DMF.
I did a DMF tolerance check & had around 18mm maximum movement including under tension.

I fitted a 3 part LUK clutch kit & when I got to the test drive, I didn't even get into 2nd gear when it lost all drive!
Removed the gearbox again only to find that the DMF had completely failed.
Lesson learned!!


The one in your link is a good price & I've purchased from that company before without issue.

Interesting to hear your DMF saga Mike. Yes, I'm beginning to think I should replace it. I don't have any previous experience with DMFs so I don't actually know whether it's faulty or not - but I sure as heck don't want to put everything back together and then find the darned thing was causing all the judder problems after all.

I missed the golden opportunity with the one in the eBay link - they were selling it yesterday with 15% off, which meant it was down to £156. I ummed and ahhed too long and missed it - now it's back up to £183 again. Damn, damn, damn etc.