Technical Dual Mass Flywheel???

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Technical Dual Mass Flywheel???

Herman Sermitz

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Sep 8, 2008
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Mines a 1.9jtd 03

replacing gearbox from 02 model. flywheel is a normal one. The starter motor needs to be changed as well.
 

andyff013

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Mar 17, 2008
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newcastle under lyme
Hi everyone, what are the symptoms of the DMF going? we have a 54 1.9jtd dynamic and it has just started to feel not quite as smooth when cruising at a constant speed ( almost feels like its miss firing on one cylinder ), could this be the DMF?
 
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I've heard recently somewhere (can't remember where) that dual mass flywheels can be damaged by doing alot of creeping along in 1st gear in traffic.

does anyone know if this is true?
 

laightsdoblo

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Sep 20, 2008
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hey there. my dads has an 05/55 1.9 doblo, he started experiencing a horrible screechig sound (to my best description) when pulling away and also trouble selecting certain gears, im a mechanic myself so had a look myself, in removing the gearbox and clutch, sure enough found that the duel mass flywheel had totally fallen apart and failed, new flywheel and clutch. job done not a complaint since from the old man
 
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That would be because they're probably not on internet, I'll drive past tonight to see if their still there.

Interestingly seems the dual mass flywheel is becoming common on petrol cars as well as my mates SEAT Leon with a DSG gearbox has had to have one replaced with clutch and horror of horrors my lease BMW 740 has one also, progress!
 

Hellcat

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DMF failures are not common!

I've replaced two, but not because the DMF was at fault. One was a failed clutch housing, the other an oil contamination of the clutch surfaces. Replaced the DMF because at the time it looked like we would be keeping the cars for at least 5 years, and while the gearbox was open and a new clutch was being fitted, it seemed like a sensible idea to put one in while we had the chance. 100,000 on the Marea 2.4 with the failed housing! DMF was still in pretty good condition.
 

Amlocks

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Jun 14, 2008
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Thanks Notts
2001 non turbo 1.9D at 140000miles.
I had new master cyl under warranty at 25000 and had to pay for new clutch then. Has been driven carefully so hoping DMF is okay. I think 110000 is good going.

My 2002 1.9JTD is now on it's second recon gearbox at 175000 miles with new clutch every time. Driven hard with lots of weight though :devil:
 
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johnson550

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Usually the DMF doesn't cause a clutch failure, but replacing the clutch without the flywheel is a no-no...

A DMF is basically a flywheel made of 3 parts. An inner disc which bolts to the crank; a outer ring which has the teeth for the starter and the friction surface for the clutch plate; and a rubber filler which joins the two taking out small vibrations from standard clutch operation.

How expencive? About £400-£450 for the flywheel making a + labour clutch change around £800-£1300 depending on how difficult the job is. 1.9JTD should be closer to £800, some of us ex 2.4JTD owners paid the bigger number!

Youve missed out the two rather large springs
 

Ffoxy

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I read an interesting article in a Trade mag recently, covering aspects of DMF testing. Its quite a complex procedure to do correctly with the right tools, with backlash measurements and torque requirements etc. Creeping along in heavy traffic is stated as a possible risk as the constant on / off of high torque on a hevily laden vehicle is quite stressful to it. But as Hellcat has stated above they are not an achilles heel, thay have brought the smooth diesel motoring experience we now have to over 90% of all manufacturers diesel vehicles.

DMF's are very commonplace.
 

Hellcat

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Youve missed out the two rather large springs

What springs? :confused:

FlyWheel.JPG


Btm_Clutch.JPG
 

Hellcat

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Nice link - never taken one of these apart before. So I take it the spring takes the majority of the power hit with the rubber just dialing out the small shocks?
 
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Creeping along in heavy traffic is stated as a possible risk as the constant on / off of high torque on a hevily laden vehicle is quite stressful to it.

I mentioned this eariler in the thread but didn't get a reply :cry:

I've heard recently somewhere (can't remember where) that dual mass flywheels can be damaged by doing alot of creeping along in 1st gear in traffic.

does anyone know if this is true?
 

Niall_G

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Interesting animation. I wonder how much energy is lost compressing the springs? Obviously you get most of it back when the spring returns to its original length but there must be some lost as heat/noise.
 
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This is an old post, I know, but I found the following description of the DMF. Most interesting was that it suggests that the design is mainly for the 200 - 400 rpm range:

if you paste:-

moodle.student.cnwl.ac.uk/moodledata_shared/cdx%20etextbook/dswmedia/trans/clutchMan/clutches/dualmassflywheels.html

you can see what they say.

This suggests to me that stop/start motoring is one contributor to failure. Doesn't bode well for the stop/start technology we are seeing more frequently.

Mike

(I did post it as a link, but it seems forum rules say I can't do that until I am a little older).
 

Ffoxy

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:rolleyes: 54,000 miles on my DMF now ater a Red Dot remap to 194 Bhp at 32,000 miles.

Still smooth as a babys soft bits and no judder or slip.... (y)

There are non DMF replacements available now, cheaper but transmits the engine and gearbox vibes a bit more so not such a "cultured" ride.
 

Hellcat

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Start/Stop shouldn't be confused with the 'start/stop' traffic. Switching the engine off will save the clutch compared to people often sitting with the engine idling, clutch pressed and the car in 1st gear.
 
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