bushwhacker Posted October 6, 2014 Share Posted October 6, 2014 Hi Is it better to replace a dmf with a new dmf or change to a smf. What are the pro's and com's. Not really sure which way to go with this at all. Any thoughts / suggestions would be great fully accepted. Quote Link to comment Share on other sites More sharing options...
dave88sw Posted October 6, 2014 Share Posted October 6, 2014 In my experience, a dmf and clutch kit should do around 100,000 miles unless used every day for heavy towing. If this is the case, very few people out there are likely to still own the vehicle by the time it needs another clutch. The price difference between the dmf and smf kit is usually quite small and so i would say go for a replacement dmf every time. The vehicle will have been designed to use one and will not be as nice to drive with a smf. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted October 6, 2014 Share Posted October 6, 2014 There's a reason Land Rover went to such lengths to select the flywheel they did. A DMF should be replaced with.....a DMF. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted October 7, 2014 Share Posted October 7, 2014 On td5s if you change dmf to solid fly wheel you most likely will break your gearbox shaft Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 7, 2014 Share Posted October 7, 2014 DMF is there for a reason. Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 7, 2014 Share Posted October 7, 2014 Until now I've stuck with DMF for the above reasons.. It's there for a reason.. (I hope) I also reason that the R380 and many other gearboxes have been behind diesels without DMF for some time so although the DMF is there to smooth out the impact on the drivetrain and lower noise etc., the gearbox would likely survive without the DMF. I have been getting through DMF's too quickly (Last one 27k, current one at 30k, condition unknown) so took my time to drive other vehicles where the owner had converted to a solid flywheel and conventional clutch. All three trucks had been using the solid flywheel for over 50k and none gave any hint of adverse reaction.. One owner said he heard some chattering occasionally but just dipped the clutch and it went silent. I heard nothing.... In the near future I'll be switching to a solid flywheel to see if the rumours are true. Only time will tell.... Neil Quote Link to comment Share on other sites More sharing options...
Blanco Posted October 7, 2014 Share Posted October 7, 2014 +1 for DMF Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted October 7, 2014 Author Share Posted October 7, 2014 Thanks guys. I've ordered a new dmf. V8Freak that really is a downer going on to a third dmf with what would seem too few miles on them. Don't know if you off road but from what I have read the dmf's do not like to have a rough time of it. Surly to god the designers/engineers could have come up with a far better option. It's all about money if you ask me and I will leave it at that. Quote Link to comment Share on other sites More sharing options...
RedLineMike Posted October 7, 2014 Share Posted October 7, 2014 Road car DMF & standard clutch Buggy solid flywheel & paddle clutch Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 7, 2014 Share Posted October 7, 2014 Since the last DMF I've slightly upgraded the engine so currently around 175 BHP and 400+ Torques... (Big thanks to the team at IRB for the upgrades... Rock solid for last 25k miles) It's mainy road use, been a daily driver for the last 55k miles... The truck is now semi-retired so happier to experminent a little and see if I can find a happy compromise. Neil Quote Link to comment Share on other sites More sharing options...
Shackleton Posted October 7, 2014 Share Posted October 7, 2014 Looking forward to hearing how you get on Neil, I'll go on your findings for my RR restoration when the time comes. Quote Link to comment Share on other sites More sharing options...
Defender Posted October 9, 2014 Share Posted October 9, 2014 I can't comment on a SMF in a Land Rover but I had a 150bhp golf that had been remapped and it ate DMFs at a great rate and I tried different manufacturers and it made no difference. I took the decision to try an SMF and it was great, there was some chatter when accelerating but it never bothered me it was just a characteristic of the setup, this lasted really well I had no issues at all. It even picked up revs quicker which made it nicer to drive. I then decided that if I ever needed to replace a DMF again in my life I would definitely go with an SMF without hesitation if one was available for that model. After all this is how cars always used to be the springs were in the clutch plate not the flywheel!!! When the clutch got worn out you replaced the clutch plate which was much cheaper than replacing a flywheel. Some people said it causes vibration in the drive train and this was bad for the gearbox however when I weighed it up it would still have been cheaper to buy a second hand gearbox and pay the labour to fit it than the cost and labour to replace the DMF (In the golf anyway!) so I took the chance and never regretted it. I obviously never had to do this and when I sold the car the gearbox and SMF were still going strong. I understand my experience isn't with a Land Rover but just the nature of how a DMF works puts me off them and the fact that each time the DMF is replaced you should ideally change the clutch which makes it expensive! Quote Link to comment Share on other sites More sharing options...
dave88sw Posted October 9, 2014 Share Posted October 9, 2014 I can't comment on a SMF in a Land Rover but I had a 150bhp golf that had been remapped and it ate DMFs at a great rate and I tried different manufacturers and it made no difference. I took the decision to try an SMF and it was great, there was some chatter when accelerating but it never bothered me it was just a characteristic of the setup, this lasted really well I had no issues at all. It even picked up revs quicker which made it nicer to drive. I then decided that if I ever needed to replace a DMF again in my life I would definitely go with an SMF without hesitation if one was available for that model. After all this is how cars always used to be the springs were in the clutch plate not the flywheel!!! When the clutch got worn out you replaced the clutch plate which was much cheaper than replacing a flywheel. Some people said it causes vibration in the drive train and this was bad for the gearbox however when I weighed it up it would still have been cheaper to buy a second hand gearbox and pay the labour to fit it than the cost and labour to replace the DMF (In the golf anyway!) so I took the chance and never regretted it. I obviously never had to do this and when I sold the car the gearbox and SMF were still going strong. I understand my experience isn't with a Land Rover but just the nature of how a DMF works puts me off them and the fact that each time the DMF is replaced you should ideally change the clutch which makes it expensive! Just out of interest, what was the nature of the failure? I've yet to feel any failure of a dmf while driving, only ever replaced if i've been in for a clutch change and found movement of the flywheel face. Cheers Dave Quote Link to comment Share on other sites More sharing options...
henk Posted October 10, 2014 Share Posted October 10, 2014 I found a smf in Newbury (neighbours of Si) and will try to change it this year but I use the 90 mainly offroad Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 10, 2014 Share Posted October 10, 2014 Just out of interest, what was the nature of the failure? I've yet to feel any failure of a dmf while driving, only ever replaced if i've been in for a clutch change and found movement of the flywheel face. Cheers Dave I had noise and severe judder when pulling away in my D2 - clutch was fine (not slipping), it was play in the DMF that was causing it so had the clutch changed along with the DMF. Quite a lot of back forth play between the plates once it was out. Rotational play wasnt that excessive though. Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted October 10, 2014 Author Share Posted October 10, 2014 Guys I have to be honest the DMF info I required was not in a Landrover but a Bora (the family hack and real easy on diesel). I knew I would get better info on here than anywhere else and I was unaware they came in TD5s. I had taken the gear box of to replace a leaky CSC.I only noticed mine out of interest as it was the first I had come up against. It was a bit on the free side on the spring thingy and wobbly side to side, which just couldn't have been correct. It may or may not have wrecked the starter or it could have been me getting the car in out of the way of traffic on it any way starter maybe needed. It never ends. What i really want is my 1986 110CSW to have a 200tdi, it has a rear disc brake axle. Plus a 90 200tdi with a rear disc brake axle or a 90 300tdi for swmbo . Just two vehicles. Transport sorted for ever I recon. Quote Link to comment Share on other sites More sharing options...
Defender Posted October 13, 2014 Share Posted October 13, 2014 Just out of interest, what was the nature of the failure? I've yet to feel any failure of a dmf while driving, only ever replaced if i've been in for a clutch change and found movement of the flywheel face. Cheers Dave As Reb78 says it judders when you pull away and the engine nearly stalls on take off as it bogs down. Basically you can feel the two halves of the flywheel moving. The clutch on both occasions wasn't worn out it was just the flywheel was broken, it's obvious when you take it out. If it's for a VW Bora 'Valeo' make the SMF kit if your interested a google search or a well known auction site may yield results of suppliers. I think Helix also make a kit but this is allot more money. Quote Link to comment Share on other sites More sharing options...
Shackleton Posted October 13, 2014 Share Posted October 13, 2014 I was just thinking, R380's survived just fine with solid flywheels before the Td5, and with tuned Tdi's cranking on them. I know there are such things as vibrations in the first and second order, and I know in that sense a straight 5 has both advantages and disadvantages over a straight 4. But isn't the main reason for a 5 cyl. that it runs smoother than a 4? Anyway, I need to know more and I found this great bit of info on DMF's : Take for example the revolutionary invention of the Dual Mass Flywheel (DMF). It’s true that flywheels have helped to eliminate cyclic irregularities of the engine for a long time. However engine vibrations at low torque or idle speed, often experienced as shaking and rattling, were still causing concern and frustration to drivers. There was only one solution to this problem: increasing the transmission’s moment of mass inertia without increasing the weight – a paradox. But this is exactly what DMF does. Function of the LuK DMF With the DMF the angular momentum is decreased in front of the torsion damper and increased behind it. The angular momentum of the engine is now assigned to the primary mass of the DMF, while that of the transmission is assigned to the secondary mass including the clutch driven plate and the clutch pressure plate. In this way, the resonance speed is shifted from approx. 1300 rpm to about 300 rpm and can no longer interfere with driving comfort., An added positive effect is provided by the reduced angular momentum on the engine side: Gear changing is improved thanks to the lower mass to be synchronised, and the synchromesh units are subject to less wear. With previous conventional flywheels and torsion-damped clutch plates, the torsional vibrations in the idle speed range were transmitted to the transmission with the least possible filtering, causing the teeth of the transmission gears to strike against one another (transmission rattle). The use of a dual mass flywheel however, filters out the torsional vibrations of the engine by the complex construction of the torsion damper, preventing vibration from affecting the transmission components – rattling does not occur, and driver comfort is fully ensured. Service innovation by LuK: the DMF on-car tool At the Automechanika 2008 in Frankfurt/Germany, Schaeffler Group Automotive Aftermarket presented a special tool allowing car mechanics to check the function of the DMF while the part is mounted. To date no such tool has been available on the repair market to perform this type of inspection. Using this special tool, workshops can now assess the operating reliability of the DMF and determine whether or not the DMF has to be replaced along with the clutch. Because a worn or defective DMF will inevitably damage the new clutch. Whenever the clutch is replaced, the DMF has to be checked as well. A full test procedure would involve the measurement of the arc spring characteristic which requires a test stand and special tooling not available in a workshop. So far, the only option available to the mechanic is a visual inspection of the part. Grease leakage, scores, discoloration etc. are initial symptoms of severe damage to one or more DMF components. Schaeffler Group Automotive Aftermarket has compiled and published comprehensive information on the design and operating principle of the DMF, damage patterns and remedial measures in the form of a video and an illustrated detailed 27-page technical brochure. -ENDS [from: http://motorequipmentnews.co.nz/articles/dual-mass-flywheels-invented-luk] So the DMF isolates the gearbox from engine irregularities. Gear wear is reduced with a DMF. But the R380 wasn't considered fast wearing before the Td5 was it? Could the difference in vibrations be that much worse? Imho if someone was to weigh up the option between an SMF and a DMF and decide that they'd take the gear rattle, or chatter as it's been described as, over having to drop the box every 90k, I wouldn't blame them. Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted October 14, 2014 Author Share Posted October 14, 2014 There will no doubt be nothing we can do about DMF other than sticking a new one in, or changing to a SMF and hoping for the best. This is a new subject to me and the way I will treat it is to ask when buying a vehicle if the DMF (if fitted) has ever been renewed/ changed and hope for an honest answer. A DMF is not the most difficult of jobs, even done in the driveway under a tarpaulin. Quote Link to comment Share on other sites More sharing options...
Tanuki Posted October 14, 2014 Share Posted October 14, 2014 Some DMFs, when they wear-to-fail, can cause other damage [Ford Transits and Mondeos, for example, can smash up the starter motor]. Personally, I like DMFs: they're one of the major contributions to having transforned torquey/powerful Diesels with not-many-cylinders from horrible rough things to truly livable-with over the last couple of decades. There's also no reason why they shouldn't last well: OK, if you insist on expecting the engine to drag a car along at 1000RPM with the throttle wide-open the DMF is going to be working hard to smooth-out the roughness and wearing itself as a result. Having analysed tachograph and RPM/speed/gear/throttle-position datalogger profiles on fleet vehicles I can generally predict which drivers are at risk of having clutch/transmission issues. Keep the revs up for smoothness, quietness and longer component-life! Quote Link to comment Share on other sites More sharing options...
tacr2man Posted October 14, 2014 Share Posted October 14, 2014 I have a dmf on my td6 engined 110 , lord knows why you need one behind a 6 cylinder bmw , engines dont get much smoother ? having enough clutch grip area is more of a concern , as is the torque going thru the r380 ! Quote Link to comment Share on other sites More sharing options...
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