Dual Mass Flywheel.

Author
Discussion

cpas

Original Poster:

1,661 posts

239 months

Monday 21st June 2010
quotequote all
I have recently been reading more and more stories (and comments in car ads) about people having problems with DMF failures on modern cars. What I don't understand is how these are different to standard flywheels, why they are commonly used, and how the failure manifests itself. Also, are they as easy to replace as a normal flywheel of arethey really difficult and expensive to procure? Are there any cars to avoid or do they all have these now?

HellDiver

5,708 posts

181 months

Monday 21st June 2010
quotequote all
Yes.

They add £350+ extra to a simple clutch change. Or the failing DMF forces a clutch change (as is happening on my 1.8 petrol Mondeo).

Adam_W

1,073 posts

199 months

Monday 21st June 2010
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I had to replace a dual mass fly on a porsche boxster, wasnt a cheap part, the old one had failed springs so the 2 sections were moving around a lot. Changed during a clutch change.

Graham

16,368 posts

283 months

Monday 21st June 2010
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my old chap had 2 replaced on his mx5 under warranty !!!

marshalla

15,902 posts

200 months

JB!

5,254 posts

179 months

Monday 21st June 2010
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thankfully, some VAG cars can be retrofitted to run old, single-mass flywheels.

paulpsz008

463 posts

207 months

Monday 21st June 2010
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Put simply there is more bits to them than a single mass.
Hence;
- More things that can go wrong.
- More expensive to replace when they do go wrong.

They do however, massively improve the drivability of modern cars. (IMO of course).

aka_kerrly

12,416 posts

209 months

Monday 21st June 2010
quotequote all
i originally just thought they were used on diesel powered cars to smooth the engine vibrations to the gearbox?

Bloody expensive for what they are and ive seen a fair few cars arrive in my local scrappy where the DMF has failed and effectively written the car off as its unecconomical to repair them, my dads Saab is in a similar position right now - clutch dying but not worth spendin £500+ on it. That said my mates dad is making a tidy bit of money on the side weighing all the fff'd DMFs in for scrap and changing VAGs to VR6/G60 based single flywheel + clutch set ups.

dave

XG332

3,927 posts

187 months

Monday 21st June 2010
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There are retro fit sets that allow for standard flywheels to bo fitted.

GreatGranny

9,097 posts

225 months

Monday 21st June 2010
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My Dad bought a Mondy TDCi last year, it was 4 years old with 40k on the clock and the DMF went after he'd owned it only 4 months. I think it was £350 to replace. He was gutted as it was a) the 1st ford he had ever owned (20 yrs of vauxhall with no problems) and b) the 1st diesel he had ever bought.
He still rates it above any of the Vauxhalls though.

TheCarpetCleaner

7,294 posts

201 months

Monday 21st June 2010
quotequote all
HellDiver said:
Yes.

They add £350+ extra to a simple clutch change. Or the failing DMF forces a clutch change (as is happening on my 1.8 petrol Mondeo).
And then some!!

When I had my mondeo and I thought the flywheel was going (rattling noise and doing odd things), I asked around for quotes.

Cheapest was £900, most expensive was £1600.

Business partners company mondeo, they billed the leasing company £1550.

Worst clutch enhancement ever to happen to cars - makes cheap high milage diesels worthless as when the clutch goes, its dead.

I will not buy a car with a DMF for as long as I can avoid it.

cpas

Original Poster:

1,661 posts

239 months

Tuesday 22nd June 2010
quotequote all
How can you find out if certain cars have them? I assumed that it was only modern diesels, but saw an advert for a Mondeo V6 which had had one changed!! Is it something that a competent home mechanic could fit?

AndrewW-G

11,968 posts

216 months

Tuesday 22nd June 2010
quotequote all
cpas said:
How can you find out if certain cars have them? I assumed that it was only modern diesels, but saw an advert for a Mondeo V6 which had had one changed!! Is it something that a competent home mechanic could fit?
If you can change a clutch, then you should be able to change a DM flywheel. Porsche have used them since the early 90's with many early failures on 911/964's to the point that many people swapped to the lighter solid flywheel from the RS

GC8

19,910 posts

189 months

Tuesday 22nd June 2010
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Porsche's problems were solved when they swapped to LUK dual-mass flywheels.

Mr2Mike

20,143 posts

254 months

Tuesday 22nd June 2010
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Quite a few petrol engines have them these days. e.g some variants of the VAG 1.8T.

mr rice

147 posts

185 months

Tuesday 22nd June 2010
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Many of them can be welded, refinished and balanced essentially converting them to the solid type which i would say is a fairly cost effective way of repair for an older vehicle.

Robert

W124Bob

1,744 posts

174 months

Tuesday 22nd June 2010
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Interestingly Mercedes Benz where fitting Dualmass flywheels to W124 models back in the 80's,even gets mentioned in the brochures of the period.And we all know how unreliable an old w124 is!

Superhoop

4,676 posts

192 months

Tuesday 22nd June 2010
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Graham said:
my old chap had 2 replaced on his mx5 under warranty !!!
There must have been something seriously wrong there then - No MX-5 (MKI, MKII, MKIII, or even the MKIII facelift model) have EVER been fitted with a DMF.....


cpas

Original Poster:

1,661 posts

239 months

Tuesday 22nd June 2010
quotequote all
Superhoop said:
Graham said:
my old chap had 2 replaced on his mx5 under warranty !!!
There must have been something seriously wrong there then - No MX-5 (MKI, MKII, MKIII, or even the MKIII facelift model) have EVER been fitted with a DMF.....
..apart from 1.....laugh

confused_buyer

6,610 posts

180 months

Tuesday 22nd June 2010
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Mr2Mike said:
Quite a few petrol engines have them these days. e.g some variants of the VAG 1.8T.
Yes, they do, although the flywheel is only about £120 (Eurocarparts to a clutch/flywheel kit for about £250). Not a major issue if the clutch has gone anyway as the labour is little extra - more of a pain if it's the flywheel and the clutch is otherwise fine.

The issue seems to be that some manufacturers seem to be able to design/spec quality DMF's which last the lifetime of the car in most cases whilst others seem to have pushed down costs so far the DMF's are fundamentally flawed designs.

A LOT of petrols have them although failure seems more common on diesels.