Dual Mass Fly Wheel

[jims-terrano]

Can someone please educate me about Dual Mass Fly Wheels and what DSG means. Why have they got a bad name or have I simply heard bad things. Are they only on autos or are they on manuals too.

Have been looking at getting a VAG instead of one of the Terranos may be even a Roomster.

[firebobby]

Originally Posted by jims-terrano

Can someone please educate me about Dual Mass Fly Wheels and what DSG means. Why have they got a bad name or have I simply heard bad things. Are they only on autos or are they on manuals too.

Have been looking at getting a VAG instead of one of the Terranos may be even a Roomster.

I Have also heard bad things about these, apparently, they are supposed to reduce vibration through the drive train
That's what a mechanic mate told me and if left, they can do serious damage

[makeitfit]

Over priced, over engineered under achieving bit of trash. Nice when they're working properly on a soft car but from friends I know who've had to change them, they're a right royal expensive PITA
Newer Patrols have them and are commonly taken out for proper clutch assy
I know no more than that

[John B]

Are they fitted to the terrano ??

[makeitfit]

Originally Posted by John B

Are they fitted to the terrano ??

Not on the older ones for sure

[jims-terrano]

Originally Posted by John B

Are they fitted to the terrano ??

Hope not from whats been said. Seriously no they aren't

[John B]

Mines an 05

[makeitfit]

Read this
https://www.google.co.uk/url?sa=t&rc...5mdeV2hiH1Ajsg

[firebobby]

Not fitted to Terrano's

[jims-terrano]

So its diesels and appears to be if theyve been abused or high mileage. Would appear to be a thing to replace at the same time as a clutch then.

[rayf3262]

Originally Posted by jims-terrano

and what DSG means. Why have they got a bad name or have I simply heard bad things. Are they only on autos or are they on manuals too.

DSG = direct shift gearbox.
Basically a conventional type of gearbox with two clutches.
Gears 1,3,5 on clutch one and gears 2,4,6 on clutch two.
To change gear the clutches are electrically swapped, up changes are done in ~8mS and down changes ~500mS.
So it offers the benefits of a manual with the convenience of an auto, consequently fuel economy is pretty close to a manual.
As for reliability I have two do over 100K miles, yes there are failures but as a percentage of the thousands manufactured it is small, probably a lot smaller than dual mass flywheel failures!
Take one for a test drive.....

[Barrbeast]

Originally Posted by jims-terrano

Can someone please educate me about Dual Mass Fly Wheels and what DSG means. Why have they got a bad name or have I simply heard bad things. Are they only on autos or are they on manuals too.

Have been looking at getting a VAG instead of one of the Terranos may be even a Roomster.

Dual Mass Flywheels are common in modern manual transmission cars to reduce noise, vibration and shock loads through the drivetrain. As opposed to a Solid Mass Flywheel whichis one solid plate, DMFs are two plates connected by dampening material (usually a mixture of springs and an oil filled cushion). One side of the DMF (and one plate) will be connected to engine and the other side (and plate) to the gearbox end of the drivetrain. As said they are only present in manual transmission vehicles

They're very effective and are used in some modern 4x4s (like Shoguns and Trols) to give them a more car-like drive.

The dampening section will deteriorate over time though and once it goes the two plates will start to rattle off each other, starting every so often when idling at operating temperature and progressively getting worse until it happens at idle all the time and then eventually the dampening section will go completely and you will lose all drive.

DMF wear is not helped by the fact that DMFs encourage lazy driving ie. less downshifting, as all the vibration is dampened so you don't get the feedback through the box from being in too high a gear. You may think everything is fine but the dampening section will be working overtime.

The problem with having them in big 4x4s like the 3.0 Trols is that the drivelines are especially beefy (the 3.0 Trol driveline is designed to handle the torque output of the big 4.2 diesel) and the 3.0 engine can, in an offroad situation, produce more power/strain than the DMF can handle. As the driveline is so beefy the DMF is the weak link and wear is accelerated.

Once the DMF goes a lot of Trol owners (like me) decide to forego fitting a new DMF and fit a solid flywheel instead, usually with a HD Clutch so that (fingers crossed) no-one has to be in there again for a long time

The SMF and HD clutch combo also gives you a small torque boost

The SMF replacement is usually a bit more expensive than a new DMF but the upside is that it won't need replaced anytime soon if at all, unlike the DMF which will definitely fail (mine went around 85/90k but I have heard of some owners whose DMF failed sooner).

When the garage opened up the bell housing on mine to fit the SMF the inside was covered in oil from the dampening cushion having failed.

A SMF replacement does give a bit more drivetrain noise and it means you have to change your driving style a bit and change down more frequently but that's not a bad thing. It definitely gives you a feeling that there's a more solid connection between the engine and the drivetrain, which I like

A point to note is that the 3.0 Terranos don't appear to have DMFs fitted (cncfabs confirmed when I was changing mine on the Trol), it's only the 3.0 Trol owners that got that privilege

[AlexD333]

I hate dual mass flywheel

Silly stupid bloody things, its the whole reason I bought a terrano infact

[Sweety]

DMF are fitted to most cars now petrol or diesel & often go before the clutch & both have to be changed at the same time often at a cost of a grand plus & that's not having a dealer do it glad to say the T2 doesn't have one or there isn't on my 55 plate as you can tell the difference

[jims-terrano]

So basically it's hard lines you can't get away from them because that's modern cars.