C5 clutch dual mass or single plate?

[qprdude]

For me, the DMF is designed to "give" . If you take away that "give", something else will "give". It might not "give" tomorrow, but the principle is in the engineering.

[GiveMeABreak]

I agree, I think most, if not all of the major manufacturers have fitted DMFs to their diesels (on 2Lt engines at least). If that vibration is not damped by the DMF, then it has to be transmitted elsewhere and this will likely be the input shaft of the gearbox - if there was a practical, safer, less risky alternative to the technology that does the same job, I think we would of heard about it by now. They can't all be wrong

[qprdude]

I've seen too many ex customers who simply welded or flanged shafts together from diesel driven pumps, Genny's etc when the Donut or Fenna coupling gave out. Worked fine for a short while, but when shafts and more, sometimes the whole kit and caboodle, had to be replaced, they realised the importance of damping.

[flying clutchman]

I doubt there's any difference in weight between the flywheels (there certainly isn't in the transits I do), the difference in pickup is because a solid flywheel doesn't 'give' like a dmf. Arguments rage over the rights and wrongs of dmf/solid but you pays yer money and takes yer choice

[GiveMeABreak]

Especially with today's modern Diesels - all the power and torque at lower revs has to be absorbed somewhere.

A few SMF horror stories here:
http://www.talkford.com/community/topic ... -flywheel/

[Oldpug]

For me, the DMF is designed to "give" . If you take away that "give", something else will "give". It might not "give" tomorrow, but the principle is in the engineering.

Blimey,I`ve used those very words on various forums on the subject of solid conversions. I saw one article about a VW group engine that broke a crankshaft after a solid kit was fitted.There are other horror stories going around also.
I`m old school,in my day a flywheel was a lump of metal that stayed on an engine for ever.DMF`s are a different ball game.All these engines are designed around a DMF,so if it comes with one keep it.

[elma]

I agree with the keep philosophy except for if the vehicle is used to tow a braked trailer. Well only if you reverse the trailer, DMFs seem to expire rapidly when you do this and a solid conversion makes more sense in my opinion.

[renagade]

I had a 2009 2ltr c5 hdi vtr+ and the clutch went and I was given the option of fitting a solid flywheel instead of the dmf and I went for the solid (it was a little cheaper ) and what a mistake that was . The vibrations that got into the cabin and while under load. It is some thing I would not do again .The only advantage I found was that the car would seem to be quicker through the gears on take off. Don't do Guy's.

[GiveMeABreak]

As many of us have said on various topics before - DMFs were designed into the car for a reason - amongst other things to take up some of the stress and vibration associated with higher torque and power at lower revs - take that protection away and the gearbox and engine crankshaft will have to bear the stresses. IIRC Valeo developed a viable 'engineered' four-part clutch kit to replace the DMF as a more cost effect solution. I can't comment on it personally as I've already had my DMF replaced.

[Paul-R]

Indeed they did. Here's the lowdown https://www.valeoservice.co.uk/en/servi ... on-kit-gen

If it's an entirely satisfactory replacement then it makes you wonder why it's not used as an OE fitment though. I suspect that the answer is money of course. Even though buying a DMF and clutch kit is dearer than the four piece replacement for us punters it might not be the case for the car producers.

[GiveMeABreak]

That's a good point Paul. I suspect that it may have something to do with the contracts they enter into with the component manufacturers when originally designing the car pre-production. With viable Electric on the horizon and all us Diesel owners - (the majority who maintain their DPFs) now being vilified and banned from driving into cities in the not to distant future -the DMF and clutch are likely to be consigned to the great scrappy in the sky before long..

[wurlycorner]

I agree with the keep philosophy except for if the vehicle is used to tow a braked trailer. Well only if you reverse the trailer, DMFs seem to expire rapidly when you do this and a solid conversion makes more sense in my opinion.

Now that's an interesting comment elma... Care to elaborate?

I do find that my c5 clutch (seems to, based on smell rather than feel) burns incredibly easily when reversing my car transporter trailer uphill. That's with an old school spring damped over-ride trailer brake system (with reverse brake stop applied, obviously) not a modern hydro-damped braked trailer btw).

What difference does the dmf make in that scenario as you see it?

[elma]

Based on using pickups and volvos with trailers they all had premature failure of the dmf. We believed it was due to the fact that the trailer brakes effectively add to the weight being moved even more as they apply when reversing We also believe that the springs in the dmf only work correctly in the forward direction and don't like being overloaded in reverse. Hence why we think the dmfs didn't work for us and were replaced with solid flywheels which faired better but drove worse in normal conditions.

[GiveMeABreak]

Clutch slip is the key with DMFs - a big no no going forwards, but generally for reversing laden trailers or caravans (and worse up inclines) the reverse gear ratio is generally too high, so people tend to slip the clutch and this can quickly wear the DMF. General advice it to try and release the clutch ASAP and don't labour it - or better still get one of those 'mover' devices and a few volunteers!

[Paul-R]

Clutch slip = heat which is death to any tempered spring whether in the flywheel or the clutch plate.