Single mass flywheel for DSG

cujet · Dec 28, 2008

Here is my thought for the day. If I were to remove my rattling DMF and install a much heavier single piece flywheel that I machined (yes I have a machine shop) How would it perform. Other that the obvious slower RPM pickup in the lower gears, the single mass flywheel might be just the ticket.

What do you guys think?

Chris

dhdenney · Dec 28, 2008

How do you cut the teeth for the starter? Anyway, from my experience, a flexplate doesn't seem like much of an engineering feat so I say go for it.

maloosheck · Dec 28, 2008

I think you might have problems with tranny in the future. One of the reason DMF is installed is to reduce knocking effect of TDI engine on the transmission gears. I am not sure if there is any thicker gearbox fluid for DSG.

Mach1 · Dec 28, 2008

Cujet, mal has a point, the DMF is there for a reason, minimize driveline vibrations and prevent driveline shock..It would not work for most people who shock the heck out of there driveline, because they dont know how to drive for longevity..

TonyJetta · Dec 29, 2008

What about a clutch hub from a standard clutch assy, welded to a standard flywheel?

Thinking out loud....

Tony

Rub87 · May 18, 2010

what about welding the DMF shut and make sure it's centered well and rebalanced?

zekthebassist · Oct 19, 2014

The welded dmf works i just got done with a 2012 passat it has a slight noise but it works

GoFaster · Oct 19, 2014

... for now.

There has to be a vibration-damping function somewhere between the crankshaft and the transmission input shaft. Traditionally, this was done inside the clutch disk (the output side of the clutch). The DMF concept moved that function to the flywheel but took it out of the clutch disk.

With the manual transmissions, the SMF was in conjunction with installing a traditional-style clutch that has vibration damping in the clutch disk.

If you just "seize" the DMF, the transmission input shaft will "feel" every power stroke, and I'm pretty sure that will shorten the life of the transmission. Whether that shortening will be relevant ... is probably something that no one has the answer to.

bl00tdi · Oct 19, 2014

Good points GoFaster. With manual tranny's it's either DMF with solid hub disk or SMF with sprung hub, never SMF with a solid hub disk.

Stutgart · Oct 19, 2014

Machining your own flywheel would be an experiment. Would you make it lighter or heavier or the same weight. I would tend to think heavy would be better.... but wait. If you were to decide to make your own, one question would be superiority of design and materials. Would the one you fabricate be superior to the one from the engineers at Wolfsburg? Another question would be cost.

My opinion of the VW DMF is pretty low, the center bearing design is completely inadequate. But the concept of a DMF is very superior to a solid flywheel for a high performance diesel car to be driven on the road. The driveline harmonic distortions are not always completely understood, and damping them are very desirable

morpwr · Oct 20, 2014

V6 dmf

Is there a V6 DMF that could be adapted? Due to the higher output, the DMF should be heavier duty, and last longer on the 4 banger. Or plan B is to adapt some of the V6 torsion dampening into a 4 cylinder flywheel. Might take some machining, but less work than building a flywheel from scratch.

arcticcat93 · Aug 7, 2020

Bump -

Mach1 · Aug 9, 2020

Wow blast from the past..

crazyrunner33 · Aug 10, 2020

Haha, gotta love the thread bump.

The SMF has been tried in the DSG by one of the diesel shops, it was replaced pretty quickly by a DMF.

Mach1 · Aug 10, 2020

Crazyrunner33...you been here a while as well..Oh yeah I wouldnt put a SMF in a DSG, especially not one that is up to the job(borderline). I would think it would push all that torque and driveline backlash right on each other, vice versa...

lemoncurd · Feb 24, 2021

zekthebassist said:
The welded dmf works i just got done with a 2012 passat it has a slight noise but it works

Hey how is that holding up for you?

backfast61 · Feb 25, 2021

So.. instead of replacing the clunky bad dual mass flywheel with the new one I bought. I could have just taken it out -the bad one-and welded it shut and put it back in.. ? I don't think so.

jetta 97 · Feb 26, 2021

backfast61 said:
So.. instead of replacing the clunky bad dual mass flywheel with the new one I bought. I could have just taken it out -the bad one-and welded it shut and put it back in.. ? I don't think so.

Agree , No way to do this .
I had car that was in flood and DMF got frozen from rust , Car was shifting very hard , like transmission is bad , and when you put in D and let brake Off car will jump and speed very high .
If they can go with SMF what makes peole think they would not do that .

dtrvler · Feb 27, 2021

Sticking a new dmf is not an expensive or time consuming job....if you do it yourself! And you only gotta do it every 100k miles or so....and they really do smooth everything out until they fail again. When mine rattle perceptably i just shop for a good price and stick one in. I have tricks that shorten the install. On a lift i can do one in an hour or two.

Tdiguy89 · Mar 28, 2024

dtrvler said:
Sticking a new dmf is not an expensive or time consuming job....if you do it yourself! And you only gotta do it every 100k miles or so....and they really do smooth everything out until they fail again. When mine rattle perceptably i just shop for a good price and stick one in. I have tricks that shorten the install. On a lift i can do one in an hour or two.

Sorry to revive this old thread, but I am looking at replacing the DMF in my 2013 (8p) a3 tdi with dsg. I am very interested in hearing your tricks as I've only pulled the transmission on a 95 altima so far. Im looking to replace my 02j in my 02 alh soon so I'm not terribly afraid of the job, just in the researching stage.
Thanks!

Rx7145 · Mar 28, 2024

Yeah, it’s a little more involved than a Altima. If you pull out the radiator fans and the flanges for the axles, that seems to be a big help. I don’t remove the lower control arm or the subframe..

Tdiguy89 · Mar 28, 2024

Rx7145 said:
Yeah, it’s a little more involved than a Altima. If you pull out the radiator fans and the flanges for the axles, that seems to be a big help. I don’t remove the lower control arm or the subframe..

Yeah, just called the shop I frequent for jobs if I don't do them myself, $2500 for the job... guess I'm gonna get really familiar with this transmission! I'll eventually have 2 to do anyway...

Rx7145 · Mar 28, 2024

Yeah, $2500 is ridiculous.

lemoncurd · Mar 28, 2024

fwiw i paid like $500 in labor 2ish years ago for a shop to do my DMF..

Rx7145 · Mar 28, 2024

$500 is acceptable.

privateTDIjet · Mar 31, 2024

I think whatever was written here is true. When I had my bad flywheel, the car would shudder really bad under 1400 rpms and when braking, i could hear a zipping / cricking noise from my transmission as if it was begging me to stop. I paid 500 for the labor and now it really is good as new. My old flywheel wouldnt have a slight side to side play between the two "plates", it would only rock back and forth the second "plate", making that clanging noise at idle.

Single mass flywheel for DSG

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