why do manufacturers install dual mass flywheels ?

pianeet

why do manufacturers have to put dmf on nearly all diesel engines,

i have had two go at work recently,ford tansit 2001 diesel,ldv convoy 2002 diesel,my old avensis d4d 2001,brother in laws passat tdi 2003,and two mates with mondeo diesels,

i have a 2004 passat with 90,000 on clock and touch wood it has been fine,but i have been looking at getting a new car,and in nearly every review for all manufaturers they seem to have premature dmf failure,

i am sure there are more, but as a lot of warranties dont cover clutch failures these are expensive faults averaging £600 with the clutch,surley it would be better to go back to a solid design

joshm_2

My guess is that people want the advantages of a diesel without the disadvantages in refinement, e.g. vibration and drivetrain noise, that a single mass FW might result in. And if manufacturers built stuff that didn't ever go wrong they'd be out of business pretty quickly!

cc25

Also, most DMF failures will occur well outside the manufacturers 3 year warranty period. I guess long term reliability is not so much of a concern to manufacturers as is new car sales. As joshm writes, smoothness and vibration reduction beats long term reliability, at least in the eyes of the manufacturer.

I had read somewhere that for some car models, it is possible to replace a failed DMF with a solid flywheel (at considerably less cost). That might be an option for some owners.

tomstickland

Always worth seeing if there's a single mass flywheel (and hopefully lighter for better performance) available.

Conor_3

pianeet wrote: »

why do manufacturers have to put dmf on nearly all diesel engines,

Because people whinged about the vibration of diesel engines.

pianeet

joshm wrote: »

My guess is that people want the advantages of a diesel without the disadvantages in refinement, e.g. vibration and drivetrain noise, that a single mass FW might result in. And if manufacturers built stuff that didn't ever go wrong they'd be out of business pretty quickly!

in my eyes its a bit like a cambelt,why fit a cam chain thats good for 150,000miles when you can fit a timing belt thats good for 50,000 and means 3 visits to dealer for maintenance, and if you dont change it there is a good chance it will snap,

pianeet

Conor wrote: »

Because people whinged about the vibration of diesel engines.

surely they would whinge more about £600 bill;)

vaio

Conor wrote: »

Because people whinged about the vibration of diesel engines.

pianeet wrote: »

surely they would whinge more about £600 bill;)

Different sections of the market. On average the people who whinge about vibration are the one who buy new cars so the manufactures pay attention to what they say, the people who whinge about the cost of the £600 bill are the ones who buy 3 or 4 year old cars and so are of limited interest to the manufacturers

harveybobbles

DMF make the gearchanges smoother. And make the Service Bay more money!

Tranny vans were failing left right and centre.

We do lots of Mondeo tdci, Volvo D5...

anewman

Sounds kind of like the timing chain versus cam-belt debate. Cam belts make dealers more money and make car run a little smoother, whereas timing chains never fail and never need renewing.

vaio

anewman wrote: »

…….whereas timing chains never fail and never need renewing.

tell that to all the 2.2l Vauxhall owners who’ve had to deal with wreaked engines