Dual Mass Flywheels - Your views?

[Volvo2002]

Originally Posted by volvorocks

After reading up on DMF they appear to be for less noise vibration and harshness, better fuel consumption,for less stress on the gearbox/ transmission from high torque output engines.It appears they are more or less being seen in some instances as a 'consumable' like brake pads are..!!!

Apparently Ford and Mazda are looking at fitting some electronic trickery to limit torque output in first and second gear instead of using DMF.

Thoroughly enjoyable research - off for a kip....

Regards

I believe our 9-5 Aero has something similar. The car won't use the overboost in lower gears (1st and 2nd) to protect the transmission. It only works in 3rd and beyond as far as I'm aware.

[Daim]

Originally Posted by Volvo2002

More moving parts = reliability compromise!

Such a good idea, shame about the execution.

A V12 engine has more moving parts than an I4. But it isn't less reliable. A ****el (hehe) has 2 moving parts (one disc) or 3 (two disc) opposed to an 8 valve 4 cylinder (cams, pistons, rods, cambelt/cogs/chain, valves, etc.). On top of that, a 6 speed gearbox has more parts than a 5 speed + DMF.

Sentences like that are rather out of place... The DMF has proven it's reliablity. If treated correctly, a DMF will last as long as an SMF. If people don't treat it right, it will f**k up as quick as a standard clutch. Years ago people would say "oh an automatic... More to go wrong". And now? As popular as a manual gearbox. People also said the same as diesel cars came out. And now? More diesels are being made than ever before. The list goes on for ever...

If the world listend to people like that, we would be living in caves!

[Volvo2002]

Originally Posted by Daim

A V12 engine has more moving parts than an I4. But it isn't less reliable. A ****el (hehe) has 2 moving parts (one disc) or 3 (two disc) opposed to an 8 valve 4 cylinder (cams, pistons, rods, cambelt/cogs/chain, valves, etc.). On top of that, a 6 speed gearbox has more parts than a 5 speed + DMF.

Sentences like that are rather out of place... The DMF has proven it's reliablity. If treated correctly, a DMF will last as long as an SMF. If people don't treat it right, it will f**k up as quick as a standard clutch. Years ago people would say "oh an automatic... More to go wrong". And now? As popular as a manual gearbox. People also said the same as diesel cars came out. And now? More diesels are being made than ever before. The list goes on for ever...

If the world listend to people like that, we would be living in caves!

A ****el (hehe

I love that word lol. Thank you Mazda

he DMF has proven it's reliablity. If treated correctly, a DMF will last as long as an SMF.

Remember Daim I'm only going on what I've heard from my own mechanic and other complaints. I believe you know what you are talking about and I take what you say seriously and find it very interesting. I'm sure if everyone drove their cars with far less aggression, the parts in general would last a long time. What do you think about diesel cars with constant DMF problems though? So many stories on younger motors like VW golfs having major judder on idle from the DMF.

[Daim]

Well, them being a VW is the main issue. VW is "supposed" to be good but they build the biggest crap you can get. If they can save €0.04 a DMF they will and that means that the DMF will be a piece of poop.

Just a side note: VW has loads of issues with the chain drive on their 1.4l TSIs. This all down to the longlife oils they use. The chains then wear off and snap. The engine is then "fried". VW has instead of saying they did something wrong, will simply modify the electrics of the car to say that the engine oil MUST be changed early instead of the proper longlife. All this so they can save money.

Kind of like Ford did with the Ford Pinto which would either burst into flames if rear ended or you'd be killed by the steering column.

So, DMFs giving up over and over again on a VW isn't anything special. Volvo has a DMF on the manual D5s. Rare change. A 5-cylinder doesn't run much better than a 4 cylinder (still isn't a smooth cycle). And the D5 puts out A LOT more torque than a 2.0TDI could. Even Volvo's D3 and D4 do...

[CJL]

I do wonder how many of these "DMF failures" are caused by abuse/poor technique.

Holding the car on the clutch on inclines, agressice gear changes etc etc...

[Daim]

Originally Posted by CJL

I do wonder how many of these "DMF failures" are caused by abuse/poor technique.

Holding the car on the clutch on inclines, agressice gear changes etc etc...

Yep! A lot are. The clutch is only there to get the vehicle moving and to change gears. It is not a tool to hold a car in place (that is what the handbrake is for). A lot of people will d that and wonder why their cars have clutch damage earlier than others.

[owyn]

A DMF working properly will protect the clutch, it stops the great big thumps of torque getting through to it.

They are a lot less troublesome on petrol cars that have smoother torque characterisitics.

[volvorocks]

Originally Posted by Daim

Yep! A lot are. The clutch is only there to get the vehicle moving and to change gears. It is not a tool to hold a car in place (that is what the handbrake is for). A lot of people will d that and wonder why their cars have clutch damage earlier than others.

Very true.

I was always taught to use the handbrake, for example when stopped at red lights. However driving instructors inform students to keep the clutch depressed nowadays, which I found unusual.

Regards

[volvorocks]

We are all doomed!

Will a DMF last 2.5 years and 45k? If so I aint bothered..lol..!!!!!

[Volvo2002]

Originally Posted by Daim

Yep! A lot are. The clutch is only there to get the vehicle moving and to change gears. It is not a tool to hold a car in place (that is what the handbrake is for). A lot of people will d that and wonder why their cars have clutch damage earlier than others.

My mum used to do this until I gave her an earful, she now does what I do, hold the brake and push the clutch to the floor! I never use the handbrake though.