Dual Mass Flywheels

[kompact]

Hi,

Hope I'm doing this correctly,new today!

Can anyone give me some advice,just bought a Rav 4 02 on a 51 plate nxd4d,specifically to tow a 850k caravan,seems I made a blunder?

I thought that a 4 wheel drive diesel would be perfect for the job but note there are some problems regarding towbar hieght and worse this dmf thing,I feel I may have bought the wrong vehicle,anyone towed successfully with one of these??

Thanks..

Welcome to the club.

Don't worry! If you trawl through these pages you will find there are many owners that use their vehicle for just the same reasons as you do and have never had a minute's trouble. DMF failure is not a given and most people successfully deal with the towbar height. If you search through the main threads you will find various views and approaches to the latter.

Enjoy your motor!

[kompact]

Hi,

Hope I'm doing this correctly,new today!

Can anyone give me some advice,just bought a Rav 4 02 on a 51 plate nxd4d,specifically to tow a 850k caravan,seems I made a blunder?

I thought that a 4 wheel drive diesel would be perfect for the job but note there are some problems regarding towbar hieght and worse this dmf thing,I feel I may have bought the wrong vehicle,anyone towed successfully with one of these??

Thanks..

Welcome to the club.

Don't worry! If you trawl through these pages you will find there are many owners that use their vehicle for just the same reasons as you do and have never had a minute's trouble. DMF failure is not a given and most people successfully deal with the towbar height. If you search through the main threads you will find various views and approaches to the latter.

Enjoy your motor!

Thanks for the welcome and your comments,

I have done a bit more on the history of this vehicle and find it had a clutch at 21000 in 2002,the dealer only has sketchy details on this but mentions 3 items being replaced and the term 'hotspots' comes up,do you think this could be a dmf problem?

It now has 72000 on it and seems to run well if a bit noisy after my A4 V6! your comments would be much appreciated,

Thankyou..

[anchorman]

Hot spots are blueish marks that appear on the flywheel facing. They may indicate that the clutch was slipped in its previous life but equally in time if the vehicle has since been driven more carefully may now have disappeared - either way it is not uncommon and only in the most severe cases will it move to the next stage which is crazing or cracking. When clutches are replaced it is fairly normal to replace the drive plate, cover plate and the release bearing. It doesn't necessarily mean the DMF will have been replaced. Sorry to be so vague but it is hard to comment without more detail.

[Blueboy]

I was rather hoping I would not have to post on the dreaded DMF Topic. I thought I'd escaped all that as I have a VX D-4D july 03 with 64000 on the clock. You know, the one with the new improved DMF?

About a month ago I heard a faint tinkle in the engine, like something was loose and rattling on the engine pan. This progressed to the "Exhaust noise", followed a day later by complete drive failure. The clutch of course I thought.

My Toyota main dealer wanted £45 for looking at it thoughtfully and a further £350 for taking it apart. As it was already towed there I was a little short of options. Diagnosis. Dual mass flywheel failure.....£1700!

I had a word with Toyota GB who were quite sympathetic, had me fax my full service history just to be sure they could do absolutely nothing to help me.

Apparently my model was not issued with the dodgy DMF that used to break all the time. No, this was the improved one that broke anyway. Apparently they could have helped if I had had the earlier one, but not the later one. Anyone else confused? Its simply a case of "wear and tear" I was told. 64000 miles! Never towed a thing! Not a lot of wearing and tearing going on.

I had to get it fixed so after a little DMF history (Thank you Anchorman) the dealer let me have it for £1500 DMF and Clutch (Should they have done the ECU, whatever that is?) I really didn't expect Toyota GB to foot the bill but some discounted parts would not have hurt and would have made me feel much better about buying another Toyota.

So is the DMF issue fixed or not? The Toyota line appears to be 64000 miles, the best you can expect from your DMF. Better get saving my diesel engined friends!

[anchorman]

Welcome to the club and thanks for sharing your experience albeit not a particularly nice one.

This issue never ceases to amaze my by the variation in results after liaising with TGB. It ranges from a full credit to nothing. The only good thing if you can call it that is the price you paid is not far off an independent doing it.

Your point about imminent failure at the 60k ish mark is an interesting one. The problem we have is that we don't have enough data to really understand what is going on. The forum and indeed the DMF section is naturally of interest to RAV owners who are having DMF issues but amongst the numerous tales of woe there are many first time posters. In other words the DMF has brought them desperately wanting to understand why their RAV is giving them such a headache from shock.

In reality although there are a relatively high number of owners that frequent the forum it is difficult to quantify just what the statistics are on DMF failure as it was only that issue that brought them here. I'm not sure that we will ever know.

I think I can feel a poll coming on specifically on this subject. Watch this space.

Finally, to answer your question about the ECU, I can only imagine that it regulates how the throttle is applied to stop you from doing racing starts. How else can an ECU improve the life of an otherwise purely mechanical component? For this reason I personally don't think it is essential for most normal drivers. I think it adds another £300 or so to the bill.

Glad you are at least sorted and hope that you can now enjoy your RAV - and please keep in touch with us.

[HEMI]

Hi,I'm new to this forum but my wife has owned a Rav 4 D4d NRG for the last 4 years with no major problems until last week when the DMF failed at 63k,as a curious bloke I checked the forums as to why such a reliable manufacturer would have such a premature problem and I found it here.I got in touch with Toyota head office and was told that my 2002 model HAD the modified DMF and even at 63k they wouldnt help me,so that led me to do it myself.Now I have a slight advantage over most people as I own and run my own garage and have done so for the last 15 yrs.I did some research and decided to go the solid mass flywheel route,I have fitted it (today) and if anyone is interested I will give driving results say in a months or so time as to whether there are any vibration/transmission problems.To anyone thinking of doing the job themselves think hard as it has taken us 8 hours to do the job in a fully fitted and tooled garage with experienced men(although it was our 1st Rav clutch job).By the way,its BS about the ECU as there is no sensor on the flywheel like a lot of cars so opt out of having the ECU "redone"

[HEMI]

OK ,I have just fitted a solid mass flywheel on my wifes Rav,it has transormed the car,it has never ran this smooth from the day we bought it,as soon as I touch the throttle it pulls immediately as before it sort of lurched bogged then went and also I can go as slow as 20mph in 4th gear and pull away very smoothly,before you wouldnt dare go so slow as it jerked and bucked and you had to go down 2 gears to get any power to the ground.In my opinion if your clutch goes get a solid mass flywheel,its cheaper and way,way better

[anchorman]

OK this is good information but it would be interesting to know how you get on with it as the implications on the long term affects of the solid flywheel are more important. I have read accounts on other forums which suggest that gearboxes and crankshafts have failed once the vehicle has covered some mileage.

As I have mooted on these pages before, manufacturers will not spend one penny more than they need to unless it it would otherwise have an adverse affect on driveability and durability and as virtually all manufacturers of vehicles using direct injection common rail engines are fitting these expensive parts I am convinced it is because they have to not because they prefer to and I would urge caution in making this move. I can only imagine that your DMF was in a poor state prior to change if it has improved the driveability as the whole principle of the DMF is to provide a shock absorber from the combustion shock and there is no doubt that normally they do.

However, please keep us informed as I think yours is the only account we have of a solid flywheel and I'm sure lots of people will be interested in what the long term affects will be.

[HEMI]

We have owned then car for 4 years now and it drove like it did since we got it,I never liked driving it as it felt slow and sluggish,we bought it with 32k on the clock and the DMF packed in at 63.5k.With the solid flywheel it drives like it should do,smooth and letting the power get through.I cannot see how a solid flywheel can cause crank and gearbox failures,once you've let the clutch out its job is done.There are no vibration or snatching issues with the new clutch whatsoever but I will keep you informed for future reference.Also the clutch plate on the DMF I took out looked hardly worn,it looked like it could do another 40k.

Just as a footnote,the first time my wife took her(its hers really)Rav out after the new clutch,she text me saying"what have I done to her car?it goes like a rocket"

I,ve just been reminded by my work mates that we have swapped DMF's from a few Hyundai Santa Fe's before too(about 3 years ago)with no problems(they only manage 25k if you tow with them)

[anchorman]

We have owned then car for 4 years now and it drove like it did since we got it,I never liked driving it as it felt slow and sluggish,we bought it with 32k on the clock and the DMF packed in at 63.5k.With the solid flywheel it drives like it should do,smooth and letting the power get through.I cannot see how a solid flywheel can cause crank and gearbox failures,once you've let the clutch out its job is done.There are no vibration or snatching issues with the new clutch whatsoever but I will keep you informed for future reference.Also the clutch plate on the DMF I took out looked hardly worn,it looked like it could do another 40k.

Just as a footnote,the first time my wife took her(its hers really)Rav out after the new clutch,she text me saying"what have I done to her car?it goes like a rocket"

I,ve just been reminded by my work mates that we have swapped DMF's from a few Hyundai Santa Fe's before too(about 3 years ago)with no problems(they only manage 25k if you tow with them)

I'm surprised that a mechanic with so many years experience can not understand how a DMF can prevent crank and transmission failure when it's principle role is to dampen the shock generated by combustion. If the power is generated in pulses then the pulses are going to be passed on down the line and if the transmission can stand it then the crank may not;

http://moodle.student.cnwl.ac.uk/moodledat...sflywheels.html

This is particularly good at showing how it works;

It sounds like I'm contradicticting here but furthermore it is not possible that changing the DMF to a solid flywheel has improved the power output of the engine. The DMF doesn't absorb any power, only smooths out the delivery. If there is a definate increase in power then it came from something else that you have inadvertantly corrected in the process.

[HEMI]

Thats b@ll@x that is about crank and transmission woes,the proof of the pudding is in the eating and we've fitted loads of solid flywheels in place of DMF's with no come backs,we've even fitted them for main dealers when they were short of technicians and we still do when they are too busy to cope with their workload.

I'm not saying the solid flywheel has given me more power,thats stupid,I'm saying that the power is instant and not being drained by the dampening of the DMF.The solid flywheel clutch has dampening springs(big ones)which do the same job as DMF but way better,I've noticed,my wifes noticed it.

I tend not to listen to these so called boffins who claim all these things about DMF's(I havent looked at your link but I can guess what its about)I tend to go by my instict and my know-how,which has served me well.

There are loads of firms producing solid flywheel conversions for loads of vehicles which in my mind should have been fitted from new.

[anchorman]

Well perhaps all the worlds current vehicle manufacturers have got it wrong then - they could have saved a fortune on DMFs and boffins if only they knew!!!

I'm only pulling your leg, keep us informed. ;)

[luke4x4tech]

Hi,I'm new to this forum but my wife has owned a Rav 4 D4d NRG for the last 4 years with no major problems until last week when the DMF failed at 63k,as a curious bloke I checked the forums as to why such a reliable manufacturer would have such a premature problem and I found it here.I got in touch with Toyota head office and was told that my 2002 model HAD the modified DMF and even at 63k they wouldnt help me,so that led me to do it myself.Now I have a slight advantage over most people as I own and run my own garage and have done so for the last 15 yrs.I did some research and decided to go the solid mass flywheel route,I have fitted it (today) and if anyone is interested I will give driving results say in a months or so time as to whether there are any vibration/transmission problems.To anyone thinking of doing the job themselves think hard as it has taken us 8 hours to do the job in a fully fitted and tooled garage with experienced men(although it was our 1st Rav clutch job).By the way,its BS about the ECU as there is no sensor on the flywheel like a lot of cars so opt out of having the ECU "redone"

8 hours !!! took your time :o you will never make bonus ha ha

[HEMI]

the official job time is 9.5 hours,there's a lot of stuff to take out before you even see the gearbox,the next one would probably take us 6-7 hours,maybe less as it was our first Rav clutch swap

[feefee]

:( hi everyone

i came across this site last night havingheard about DMF for the first time from my local ibdependant garage. Looks like my little rav4 is iamong the casulties. It's a 2005 mode; with 51 000 miles on the clock. it seems as though my symptoms were pretty typical as well. I had a noisy knocking sound coming from under the bonnet for the last few weeks. It came and went actually as did the grinding sound when going into reverse and also something similar to a dodgy exhaust sound when accelerating. I took it to my local garage and it was booked into to get a new clutch and when all the noises stoppped we decided to run it for a while before doing the clutch job as the garage weren't totally convinced it was the clutch. Hpwever the car bbroke downa few days later, losing drive power. It felt like I was drivng with the car in neutral with no gears respondiing.

I haven't got a quote yet for the repairs but already feel depressed from looking at what others have to pay. I treid contacting toyota who said that I hadve no come back as it is a 2005 model and also because my last service was carried out by my local garage.

If the dmf fails will it be very likely that the clutch needs replacing too. Or would others suggest I have it done anyway because of the labour involved.

Oh, I am the secomd owmer. I bought it at 18months old with 17 000 miles on the clock.

thanks everyone

fee fee ( I was such a toyota convert as well) :(

[feefee]

oops

terrible spelling

I must check my messages before I send them

[anchorman]

I think it would make sense to have the clutch changed at 51k while the gearbox is out as it isn't going to cost that much more. In a lot of cases you can buy a DMF kit which includes a clutch anyway.

As TGB are unwilling to help I would find a good local independant to do the job. You could avoid paying retail on your parts by buying them yourself - I found this on ebay;

http://cgi.ebay.co.uk/DUAL-MASS-FLYWHEEL-C...alenotsupported

[feefee]

thanks for advice anchorman. Just feel pretty flat about the whole thing.

I think it would make sense to have the clutch changed at 51k while the gearbox is out as it isn't going to cost that much more. In a lot of cases you can buy a DMF kit which includes a clutch anyway.

As TGB are unwilling to help I would find a good local independant to do the job. You could avoid paying retail on your parts by buying them yourself - I found this on ebay;

http://cgi.ebay.co.uk/DUAL-MASS-FLYWHEEL-C...alenotsupported

[Blueboy]

I was rather hoping I would not have to post on the dreaded DMF Topic. I thought I'd escaped all that as I have a VX D-4D july 03 with 64000 on the clock. You know, the one with the new improved DMF?

About a month ago I heard a faint tinkle in the engine, like something was loose and rattling on the engine pan. This progressed to the "Exhaust noise", followed a day later by complete drive failure. The clutch of course I thought.

My Toyota main dealer wanted £45 for looking at it thoughtfully and a further £350 for taking it apart. As it was already towed there I was a little short of options. Diagnosis. Dual mass flywheel failure.....£1700!

I had a word with Toyota GB who were quite sympathetic, had me fax my full service history just to be sure they could do absolutely nothing to help me.

Apparently my model was not issued with the dodgy DMF that used to break all the time. No, this was the improved one that broke anyway. Apparently they could have helped if I had had the earlier one, but not the later one. Anyone else confused? Its simply a case of "wear and tear" I was told. 64000 miles! Never towed a thing! Not a lot of wearing and tearing going on.

I had to get it fixed so after a little DMF history (Thank you Anchorman) the dealer let me have it for £1500 DMF and Clutch (Should they have done the ECU, whatever that is?) I really didn't expect Toyota GB to foot the bill but some discounted parts would not have hurt and would have made me feel much better about buying another Toyota.

So is the DMF issue fixed or not? The Toyota line appears to be 64000 miles, the best you can expect from your DMF. Better get saving my diesel engined friends!

Hi Anchorman. Thank you for the kind words. Just thought I'd let you good people know about my reply from Toyota Gb on the DMF issue described above. They were quite sympathetic but not enough to contribute towards the repair.

However they did say something quite interesting

"...after consulting with our technical department here at Toyota gb plc they have stated that dual mass flywheels, unlike solid flywheels can and do require replacement as they are a consumable."

A consumable? I don't remember seeing that listed in my service documentation? That does seem to be a change in position from what I've read on these threads. And it also begs the question if the Toyota technical department already know that solid flywheels do not require replacement why are they fitting dmfs and then charging us to fix them? Not sure where that leaves us?

[Parts-King]

This has always, and will always be an emotive subject, however I suppose it is true to say a DMF is a consumable part, but not your normal type of consumable. I suppose you should look at the definition of the word consumable

A consumable is something that is capable of being consumed; that may be destroyed, dissipated, wasted

A DMF by it's very nature can become destroyed over a period of time, unlike a solid flywheel which would take a lot to "destroy" The need for a DMF has been excellently covered by Anchorman in this thread previously, the hard bit to swallow is the total cost of doing this repair and the haphazard way that warranty/repairs have been handled by Toyota, the fact remains though that DMF failure as a percentage of RAV's on the road is tiny

Kingo

[Uncle Bob]

Is this price for real :o

http://cgi.ebay.co.uk/AVENSIS-RAV4-RAV-4-D...8QQcmdZViewItem

[Davrav]

Is this price for real :o

http://cgi.ebay.co.uk/AVENSIS-RAV4-RAV-4-D...8QQcmdZViewItem

I think stocks may last a while at that price

[HEMI]

solid flywheel is the way to go

[hertsnminds]

A consumable is something that is capable of being consumed; that may be destroyed, dissipated, wasted

How many parts of a car are not capable of the above?

The recent scrappage allowance is for cars older than ten years, does this suggest the reasonable expected life of the non consumable parts of a vehicle is ten years?

Part of the problem is there are no benchmarks for the life of any part, brake pads, tyres, clutch, Wiper Blades and a lot of things are dependent upon usage. So as a consumer all you have are other consumers experiences to compare against and for some parts the manufacturers recommended service (replacement) interval. If Toyota now state the DMF is a consumable it's replacement (and checking) should be stated in the service schedule for the vehicle.

[anchorman]

I think it is a case of putting things into perspective and I suspect that given the opportunity Toyota might like to rephrase that comment. However, if you take it to the extreme you could say that most parts of a vehicle are consumable. The obvious ones are tyres, exhausts, brake pads and clutches. It you take it a stage further and look at items that might statistically fail then you might certainly expect brake discs and eventually a flywheel. Both are wearing parts by design but a DMF has an additional function of being an engine/transmission damper with a fairly unpleasant and fatiguing function of absorbing the shock of combustion.

Perhaps it can be explained better if you consider what happens during combustion. In a petrol engine combustion is a fairly controlled occurrence and the burning fuel pushes down on the piston for a lot of the power stroke in an even manner rather like working the pedals of a bike. In a diesel there is a pronounced explosion near the beginning of the power stroke and in the case of the bike it is more like attempting to give a single and rapid push in the first quarter of the downward stroke then back pedaling again. In a common rail direct injection engine this goes another stage and is more like a workman trying to knock those pedals down by swinging a mallet down on each pedal in turn. It isn't controlled it is a violent shock right at the top of the stroke.

In this respect you have to have a little respect for the DMF and the life v abuse it endures. there is no doubt that as with all things mechanical it will either be developed to give longer life or more likely it will be phased out as manufacturers move to auto transmission only vehicles. That is certainly an aspiration of Toyota and if it sounds ridiculous it isn't so long since we were saying you could never replace a manual choke. The point is that the only way a vehicle designer can absolutely guarantee how a vehicle behaves is to remove more of the functions and control from the driver and it will be emissions that finally drive this change.

HEMI.

When you first posted your intention to fit a solid flywheel to your vehicle I was genuinely interested as it would be useful to have some first hand experience of doing that modification but your account of things took a turn for the worse when after a very short period of time you reported all sorts of curious statements and the latest - "solid flywheel is the way to go" is uninformed and irrational. It seems that all the expertise and millions of pounds in development that Toyota, BMW, GM, Audi and many more have spent in controlled testing and development has been proved worthless in your workshop and one week of testing. The problem is that these sweeping statements could cause someone without any knowledge to make very expensive mistakes.

If you were to discuss the matter with any of these "b@ll@x talking boffins" that your "instinct tells you to ignore" they will probably make an uneducated guess that if you cannot feel the vibration it is being absorbed by the crankshaft and gearbox shafts twisting beyond their design limits and that it is probably not a good idea.

At the end of the day this is an open forum and you are entitled to your opinion and I am entitled to urge caution. These manufacturers are fitting these things on more than a gut feeling.