DMF To Solid Conversions. Worth It?

[warren t claim]

Right then, other than the mechanic losing the radio code and fucking the taxi radio up early reports suggest other than a sharper clutch it seems fine and dandy, no vibes and much quieter.

[skattrd]

I'm a bit late to this, but I did the DMF to sold flywheel conversion on my boring last year.

I had the clutch replaced the year before, and was told the DMF was ok, and within tolerance so didn't replace that. I had issues after that, and spoke to a few people who said that even if the DMF is within tolerance it should be replaced when you do the clutch. I then priced up a new DMF and I could get a solid flywheel and new clutch cheaper, so i went that route.

For me the solid flywheel is gr9, it does have a little vibration, but nothing drastic, and next time the clutch needs doing it'll just need a cheap clutch fitting.

[dieselnutjob]

I did a solid flywheel conversion on our 806 HDI about 80000 miles ago and it's fine.  The engine is slightly harsher on full bore acceleration but it's a small difference and the overall refinement is still fine.

 

It could well be that these engines are smoother than the Fords though.  The Xantia 110 didn't have a DMF and neither did any of the 90 bhp versions, so maybe it doesn't really need it.

[spike60]

I'm a bit late to this, but I did the DMF to sold flywheel conversion on my boring last year.

I had the clutch replaced the year before, and was told the DMF was ok, and within tolerance so didn't replace that. I had issues after that, and spoke to a few people who said that even if the DMF is within tolerance it should be replaced when you do the clutch. I then priced up a new DMF and I could get a solid flywheel and new clutch cheaper, so i went that route.

For me the solid flywheel is gr9, it does have a little vibration, but nothing drastic, and next time the clutch needs doing it'll just need a cheap clutch fitting.

The problem may be finding what clutch you now have, it will be a different one to the standard DMF one. 

[skattrd]

The problem may be finding what clutch you now have, it will be a different one to the standard DMF one. 

 

 

With VW it's quite easy - G60 solid flywheel and VR6 clutch replace the DMF setup on the 5spd boxes like mine. This means replacement clutches are easy to source, as well as being stronger than the oem setup.

[Stixy]

Automatics  seem to survive ok without dmf's  

[RichL]

There's no right or wrong answer to this one is there? Seems to depend on the manufacturer/make/model/engine... And what sort of life said vehicle leads.

 

The early Focus 1.8TDDi (non common rail) used a solid flywheel and the Ci just has more power (and bigger driveshaft's i think).

 

In my experience VAG stuff uses mainly SACHS DMF's and they last FOR EVAR.

[dangerousdave]

after reading all this if solid flywheels can cause the trouble as stated then it says to me things aren't built as good as they should be from the factory because cars were perfectly fine with a solid one for decades

but I do know someone with an 06 plate vw caddy who had it converted and there was no difference

[Bren]

Moden diesels can put out over 300 NM of torque - so they probably do need something more advanced than a standard item.

 

As I said in an earlier thread, we want motors that can do 60 mpg, transport 5 people and do over 130 mph.

 

The price for this is being bummed when they go tits up.

 

We can't have everything.

[dangerousdave]

as far as I know cos im no good with modern stuff autos don't actually have a flywheel they have a flex plate as they don't have a clutch as such

[Stixy]

Yes a flexplate  instead of a flywheel or dmf   but the engines are the same as manual ones and they dont snap cranks or vibrate 

[jonathan_dyane]

This is true but I imagine the smoothing effect of the torque convertor 'fluid flywheel' would serve the same purpose of a DMF (only do the job rather better...)

 

In a sense the DMF is something of an aberration to allow us to persist with manual gearboxes and clutches. (This from the man who has just bought a car with a DMF...)

[oman5]

what, so is the fitment of DMFs necessary because of the greater power produced by modern engines? just wondering what was wrong with the old solid flywheels.

[Spiny Norman]

I always thought it was to try and make diseasels vaguely tolerable to drive? Don't they calm down some of the shunt and vibrations from the tractor engine or something?
Doesn't explain why they fit them to some petrol units mind....

[Station]

Scrap it.

[tooSavvy]

..... vaguely related issue -

 

How many kids who learned in a tractor (corsa mebbies) and NEVER stalled it.... went on to buy a pezz and embarrassed themselves at roundabouts

 

I know of at least one.....

 

 

TS

[dollywobbler]

I found myself regularly stalling a VW Crafter on Friday. Modern diesels just aren't as forgiving as old-school ones! You have to go some to stall the Disco.

[Asimo]

 

A LuK Dual Mass flywheel

 

http://www.luk.co.uk/content.luk.co.uk/en/products/dampers/zms_sv/zms_sv.jsp

[Stroller133]

Modern diesels also produce that high torque at low engine speeds, so the power torque is produced by 4 'bangs' each cycle, relatively a long time apart. In a high powered/torque petrol enginesthe revs would be much higher so the gaps between the power are much shorter. I imagine that 6, 8 & 12 cyl engines would less likely need dmf as the power is delivered in shorter gaps.

[skattrd]

I don't think dmf are used because of the torque.

My experience of these is limited to the boring, but when tuning the engine past 140bhp or 300nm torque it is advisable to fit the solid flywheel as the dmf on these can't handle it.

[Stroller133]

It's not to handle the torque as such, it to remove the effects of it from the drivetrain, and for the driver not to feel it. I imagine immense power would be better with solid as the springs on the dmf must have to be rated for the job.

Its a solution to a problem, that on the whole works, but introduces more moving parts and hence more risk of failure. The problem is it works for the first owner, company car driver having a fast economical, smooth car, but the second owner is left facing a bill for more than the cars worth. But who are the manufacturers making the cars for - not us!

[beko1987]

I got very lazy with my 206 2.0hdi. Could bring the clutch up anyway I wanted and would be doing near 20 before having to put the power on more. Took fucking months to get used to the pumas "easy. Easy, easy ah stalled, your phones disconnected from the head unit as it restarted and killed the music..."

[Formula Autos]

Depends on the engine, I think.

 

I had a Mondiesel until fairly recently as my daily driver. The clutch was going (at 90+K) so, while that was getting wanged out, I thought I'd ask the garage to change the DMF as well (to minimise labour costs in the long run - the car is already in bits, after all).

 

I solicited opinion from a few colleagues and acqauintences and found that a couple had had solid flywheels fitted to VAG diesels, with seemingly decent results - not as smooth as they were, but certainly tolerable. However, I found someone who had a Mondiesel like mine, who had had a solid flywheel fitted - it was horrible: dead easy to stall, and when backing off at speed the engine shook about quite a bit on its mounts. He also told me that it would regularly seem to move its exhaust around too much, with all the associated problems that creates. All of that could have been down to knackered engine mounts or something, I suppose, but I didn't risk it - a DMF was fitted. When I got the car back, all was well, obviously.

 

Except to my wallet. The bill came to, in my currency units, approximately 1 and a half Jags (an XJ40 worth having being, approximately, £500).

[warren t claim]

Thread bump!

 

I had a spin in this again for the first time in 18 months and it's still running perfectly after 80,000 miles. Not sure what that proves.

[Dick Cheeseburger]

The clutch on my daily pd130 A4 snotter is really thin, although it doesn't seem to have got any worse in the last 5000 miles I've done with it. I've considered the pros and cons discussed in this thread. My solution is leave the whole lot, whack a new mot on it next month and try and flog it as. If that doesn't work, I need to find an old dear to crash into the side of it or something. I can't bring myself to spend around £500 on parts, then factory in labour on an old snotter which is rougher than Daniella Westbrook's nasal passages.

[Tamworthbay]

My mate did this on his mondeo tdci when he lunched the clutch reversing a caravan up a slope. I have been in it a few times and it seems fine, no complaints from him either and I am sure he would of if there had been any issue.

[flat4alfa]

R-M-C

 

ready mixed concrete?

[flat4alfa]

How long do DMFs last?  I've read plenty about 40k Transits and 70k Vectras.

 

Ok, depends on use obviously, but I've been blatting about in my Alfa 156 5-pot derv for years as a daily and the 'getting heavy' clutch hasn't got any heavier or crunchier in 3 years.  It's now pushing 170k, never been apart as I have the full service mystery to prove

 

Likewise manufacturers.  Valeo is the brand to go for on these I'm told.  But which to avoid?  Only that they've been around a while now and I was by now expecting the market to be flooded with chinese pigmetaltastic cheapies found as enticement at the checkout in Poundland

[dieselnutjob]

I did a bit of googling on the BMW engined 75 and Freelander.  Curiously the DMFs on these seem to last forever and rarely cause a problem.

 

On the PugCits they seem to be of medium reliability but then not too bad without them either so you win either way.

 

It seems that Ford ones (from what people are saying here) are both necessary for refinement and short lived with a nasty habit of taking out starter motors with them, so you loose either way.

[gordonbennet]

It's a tricky one, and going back to the overheating of clutches coming out of Bluewater, i'm not surprised.

 

The trouble with these modern Diesels is that whilst they are powerful once up to turbo spool revs, they've often got sod all at tickover (keep those emissions low for VED purposes) and where years ago you could just engage the clutch gently with no accelerator at all and the vehicle would just drive gently away thats no longer the case, to get these modern bastard things to move you need a hefty bootful of throttle or they stall out, so you need the DMF or you're going to feel every detonation, especially of a 4 cyl tractor engine.

 

Factor in that older Diesels usually had low first and reverse gears to get the vehicle moving, again thats no longer the case so more clutch slipping and throttle required to get them going, when you have that at every junction then hot clutches and early DMF demise are on the cards.

 

Apart from that, no bugger seems to be able to drive any more, car doesn't have hill hold they can't do a bloody hill start, and for fucks sake whats it come to when virtually all artics with Arsetronic gearboxes have hill hold (and now getting electric parking brakes too!!!), has the standard of lorry driver reached so bloody low that they can't control the fuckin thing any more, Jesus wept.