Hilux Posted November 11, 2012 Share Posted November 11, 2012 Does anyone have any experience of having these changed or views on their lifespan in a motorhome? I now why they are used in modern vehicles powered by diesel engines and I have one in my vehicle so I was trying to anticipate its life expectancy. I am told that they sometimes fail in heavily laden vehicles at about 50K or so. H Link to comment Share on other sites More sharing options...
paulmold Posted November 11, 2012 Share Posted November 11, 2012 I haven't got one on the MH but have had them on my last 7 cars (used as taxis), I've had two Skodas (VW of course) from new and they lasted 150k without changing and may have lasted much longer but I sold them. Since then I've bought second hand ex-lease cars that have had the DMF changed after as little as 54k and 65k (both Toyotas), Vectra at 100k and another Skoda at 110k. When you buy second hand you don't know how it's been driven before you get it. I have heard of Mondeos eating DMF on cars used as taxis with as little mileage as 16k. Unfortunately with the high power being produced on modern diesel engines you exchange smoothness of take-off with poor reliability of clutches. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 11, 2012 Share Posted November 11, 2012 I think you own a Pilote motorhome based on a Mercedes Sprinter with 2.7-litre 5-cylinder motor. GOOGLE-ing on "Mercedes Sprinter DMF" retrieves a few 'hits', but that would also happen if one replaced "Mercedes Sprinter" with "Ford Transit", Peugeot Boxer", etc. I don't believe there's a prediictable lifespan for a DMF. It ought to be the case that the DMF of a lightly-loaded vehicle, or of a vehicle driven sympathetically, should have a longer life expectancy than a DMF of a vehicle normally run at its maximum overall weight and/or driven harshly. Similarly, anything likely to put extra stress on the clutch (eg. towing) should be expected to shorten a DMF's life. But (like people) some DMFs die early for no obvious reason, while others just go on and on. I recall reading letters in the Caravan Club magazine from owners of DMF-equipped Ford cars complaining that the DMFs had failed when manoeuvring a caravan on a campsite, but that's a self-inflicted wound as far as I'm concerned. If there's currently no sign of impending clutch-related problems on your Pilote, I suggest you don't worry about DMF failure - and keep your fingers crossed! It is possible with some vehicles to replace a DMF with a traditional (and cheaper) SMF (Single Mass Flywheel) clutch assembly. This would appear to be so with your motorhome. http://www.ebay.co.uk/itm/SINGLE-MASS-FLYWHEEL-CLUTCH-KIT-MERCEDES-SPRINTER-00-06-316-CDI-4-00-5-06-/230836515340 Link to comment Share on other sites More sharing options...
paulmold Posted November 11, 2012 Share Posted November 11, 2012 Derek Uzzell - 2012-11-11 9:47 AM It is possible with some vehicles to replace a DMF with a traditional (and cheaper) SMF (Single Mass Flywheel) clutch assembly. This would appear to be so with your motorhome. http://www.ebay.co.uk/itm/SINGLE-MASS-FLYWHEEL-CLUTCH-KIT-MERCEDES-SPRINTER-00-06-316-CDI-4-00-5-06-/230836515340 I would not recommend this course of action. Having had many replaced over the years as stated in my post above, I asked about doing this to my mechanic who refused to do it as he says the stresses that would apply to the flywheel would go to the crankshaft instead and ruin the engine instead. Link to comment Share on other sites More sharing options...
Hilux Posted November 11, 2012 Author Share Posted November 11, 2012 From what I can gather these things fail under continual applications of high torque. That is when the vehicle is driven in a higher than appropriate gear and then the accelerator is floored to deliver max speed. When this happens both the clutch springs and DMF springs are placed under maximum load. Continued operation in this fashion, with a heavily loaded vehicle, leads to premature failure. If gears are used appropriately then DMF life is extended. I too disagree with above claim about replacing the DMF with a conventional flywheel. This would result in high torque being transmitted to the gearbox and on to the differential without the buffer of the DMF in between. Yes Derek you are right about my ownership of a Sprinter 316 base vehicle and this is what prompted my question. I have trawled Merc forums for similar faults. At present my transmission seems OK at 40K miles, but I have recently seen a VW 3.5 tonne van showing DMF failure at about 50K. As you know this base vehicle shares components with the Sprinter. H Link to comment Share on other sites More sharing options...
Guest Peter James Posted November 11, 2012 Share Posted November 11, 2012 Thing about a DMF is that it does the job of a much thicker, heavier flywheel, So it saves weight, and makes the engine more responsive. But having less metal in it to absorb heat, it heats up much quicker, and having springs and moving parts is more easily damaged by heat. So a big factor will be how much you slip the clutch, as this produces lots of heat. Link to comment Share on other sites More sharing options...
Guest 1footinthegrave Posted November 11, 2012 Share Posted November 11, 2012 It's all B******S these DMF flywheels, there was a time that the very last thing that would EVER give trouble was a flywheel, unless that is you go way back when you may have had a new starter ring shrunk on in the good old days before pre-engaged starter motors. Now there are reports of some failing in as little as 30k miles, my daughters Mondeo diesel took the starter motor with it when the DMF failed at 66k, and was left with a hefty bill. I drove an FX4 cab years ago, the work that these vehicles did was nothing short of astounding, 300,000 to 500,000 miles was commonplace most vehicles never leaving a city environment, just think of the pounding the drive train got, all on a diesel engine without a DMF, Particulate filter, EGR valve, or turbo insight, trust me, in many ways we've gone backwards, oh and it was easily affordable to obtain recon injectors for just a few quid, which was just about the only thing required engine wise in it's lifetime, oh well progress eh. Link to comment Share on other sites More sharing options...
Guest Peter James Posted November 11, 2012 Share Posted November 11, 2012 1footinthegrave - 2012-11-11 5:00 PM It's all B******S these DMF flywheels, there was a time that the very last thing that would EVER give trouble was a flywheel, unless that is you go way back when you may have had a new starter ring shrunk on in the good old days before pre-engaged starter motors. Now there are reports of some failing in as little as 30k miles, my daughters Mondeo diesel took the starter motor with it when the DMF failed at 66k, and was left with a hefty bill. I drove an FX4 cab years ago, the work that these vehicles did was nothing short of astounding, 300,000 to 500,000 miles was commonplace most vehicles never leaving a city environment, just think of the pounding the drive train got, all on a diesel engine without a DMF, Particulate filter, EGR valve, or turbo insight, trust me, in many ways we've gone backwards, oh and it was easily affordable to obtain recon injectors for just a few quid, which was just about the only thing required engine wise in it's lifetime, oh well progress eh. Can you remember how noisy, smelly, polluting, underpowered, and shake your guts out the old diesels were as well *-) Stuff like Dual Mass Flywheels and Electronic engine management can be a pain in the a*se, but they are what makes modern diesels so much better. Link to comment Share on other sites More sharing options...
Guest 1footinthegrave Posted November 11, 2012 Share Posted November 11, 2012 Yes I do of course, but I simply think a modern diesel engined vehicle is far less reliable in mileage terms than was the case years ago, that's the only point I'm trying to make. I had a 1994 Passat diesel, that never struck me as an unrefined car, quite the opposite in fact, but it did not have any of the problems faced by more modern diesel engined car buyers, and don't get me started on "forced regeneration" or diesels cars being unsuitable unless you take them for a blast every few weeks or so ! :-( :-( Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 11, 2012 Share Posted November 11, 2012 paulmold - 2012-11-11 10:35 AM Derek Uzzell - 2012-11-11 9:47 AM It is possible with some vehicles to replace a DMF with a traditional (and cheaper) SMF (Single Mass Flywheel) clutch assembly. This would appear to be so with your motorhome. http://www.ebay.co.uk/itm/SINGLE-MASS-FLYWHEEL-CLUTCH-KIT-MERCEDES-SPRINTER-00-06-316-CDI-4-00-5-06-/230836515340 I would not recommend this course of action. Having had many replaced over the years as stated in my post above, I asked about doing this to my mechanic who refused to do it as he says the stresses that would apply to the flywheel would go to the crankshaft instead and ruin the engine instead. I was not recommending replacement of a DMF with a non-DMF one - I was merely saying that a) it was possible, b) kits were available to do it and c) a kit was apparently available for a Sprinter like Hilux's. Link to comment Share on other sites More sharing options...
spospe Posted November 11, 2012 Share Posted November 11, 2012 If you have a search of the Transit Forum at: http://fordtransit.org/ you will come across pages and pages of discussion about DMF and how to replace one with a solid flywheel. DMF do give problems, but many high mileage users cover 100,000's miles without a glitch, so it does seem that there is a bit of luck involved. Driving too slowly in too high a gear seems to be one factor in making them fail early (too much shuddering / vibration causes the springs to fail). Link to comment Share on other sites More sharing options...
hallii Posted November 11, 2012 Share Posted November 11, 2012 I believe that the way the clutch is operated can significantly affect a dual mass flywheel. Failure to match engine speed to road speed when changing gear will produce a strong jerk, these jerks impose high torque loading on the flywheel. Driven with mechanical sympathy DMFs will last a very long time. Unfortunately it is not easy to judge our own individual driving styles, and mine may be no better than anyone elses. Any Advanced Driving examiner will quickly pick up on poor driving habits, and believe me the report can be very interesting! H Link to comment Share on other sites More sharing options...
Guest 1footinthegrave Posted November 11, 2012 Share Posted November 11, 2012 Just picked this up, VERY interesting about the Ford Transit option though, I mean why would they offer that option. The AA's technical specialist Vanessa Guyll said: “Any modern vehicle with a diesel engine will come with a dual mass flywheel. Although Ford offers the Transit with the option to have an engine with a standard flywheel. Not all DMFs will suffer problems, and they do seem to be getting better but there have been plenty of problems with them, and commercial vehicles will have that same potential for failure.” Link to comment Share on other sites More sharing options...
Guest Peter James Posted November 11, 2012 Share Posted November 11, 2012 hallii - 2012-11-11 6:49 PM Unfortunately it is not easy to judge our own individual driving styles Good point - it is easier to see the flaws in other people's driving than it is for us to see the flaws in our own. I am frequently reminded of mine *-) Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 12, 2012 Share Posted November 12, 2012 1footinthegrave - 2012-11-11 7:13 PM Just picked this up, VERY interesting about the Ford Transit option though, I mean why would they offer that option. The AA's technical specialist Vanessa Guyll said: “Any modern vehicle with a diesel engine will come with a dual mass flywheel. Although Ford offers the Transit with the option to have an engine with a standard flywheel. Not all DMFs will suffer problems, and they do seem to be getting better but there have been plenty of problems with them, and commercial vehicles will have that same potential for failure.” All Mk 5 (and earlier) Ford Transits with a manual transmission had a Single Mass Flywheel (SMF) clutch assembly. The Mk 6 Transit (released in 2000) had a SMF or a DMF clutch assembly depending on the model. This was also true for the subsequent Mk 7. There's a listing here: http://fordtransit.org/forum/viewtopic.php?f=40&t=94462 As far as I'm aware it is not (and never has been) possible to opt for a different clutch assembly to what Ford factory-fits as standard. For example, my Hobby motorhome is based on a Transit Mk 6 with 125PS 2.0litre motor factory-fitted with a DMF, but it could not have been ordered from Ford with a SMF. However, because DMFs are expensive to replace, Ford began to offer cheaper SMF 'repair kits' for Mk 6/Mk 7 Transits. These were already available from (I think) Valeo and Ford just decided to officially recognise thiose kits and approve their fitting by Ford main agents. Link to comment Share on other sites More sharing options...
euroserv Posted November 12, 2012 Share Posted November 12, 2012 Hello, Without exception every RWD Transit that we have seen since about 2001 has had a DMF failure. The symptoms are always the same with the first sign being the starter motor not working properly. This is because it is clogged up with metal filings from the DMF that is breaking up. If not attended to there have been several cases where the filings have also gotten into the gearbox (not sure how, but it happens) and this has resulted in several very costly gearbox repairs or replacements. For these reasons we have been fitting the Valeo SMF kit on all Transits that it fits and that is the end of that. No more problems and no reported issues with noise or harshness. It is a stupid idea that does little more than generate income for the dealers. There may be benefits of enhanced smoothness on cars but even on these I think it is lazy engineering. There are other ways to improve the driveability and comfort of vehicles but they are more difficult and more expensive to implement. This is obviously why the engineers grasped the opportunity to install them without considering the wider implications or costs to the owner. In all cases I would say that at the first sign of any problems that could in any way be clutch or DMF related you should fit a conversion kit if it is available for your vehicle. Nick Link to comment Share on other sites More sharing options...
trevor166uk Posted November 13, 2012 Share Posted November 13, 2012 As ever Euroserv's reply is very informative. As the owner of a Ducato with a 2.3 120bhp engine I would be interested to hear his opinion of the flywheel of those vehicles. Do they too have a dreaded DMF and can I expect trouble with mine Regards Link to comment Share on other sites More sharing options...
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