Please help me understand flywheel shudder

I have a very basic understanding of cars, so please bear with me.

Malone stage2 in march 2019, 24k miles or so. Was getting boost spikes and a bit of shudder on OEM clutch. After a couple of tries Malone was able to mostly tune away the spike, and shudder no longer noticeable.

Fast forward 10 months and 25,000 miles... starting to see some clutch slip. Local shop installed Sachs performance clutch, Sachs DMF which was shipped overseas from darkside.

After break-in began testing it out a bit and found shudder to be back and worse than it ever was with OEM setup (2200-2300rpm). I was experiencing shudder under certain circumstances even in 3rd. Local shop took logs, sent to Malone and darkside for evaluation. Ultimately ended up detuning significantly which has completely gotten rid of the shudder, however car is no longer nearly as sporty as it once was.

I'm a bit frustrated after spending $2,500 on a new clutch as I feel that OEM clutch setup could have handled current tune.

I'm not looking to throw blame around, I understand the tuning world is not precise. I'd just like to understand a bit more what might be going on with my car.

beechfront said:

I'm a bit frustrated after spending $2,500 on a new clutch as I feel that OEM clutch setup could have handled current tune.

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Unfortunately, you're probably right. But perhaps Malone can now dial some of the power back into your tune to reach a middle ground. Odds are that if your OE clutch was slipping it wasn't long for this world even if you'd install the milder tune.

Yes agree... damage already done on the clutch over past 25k miles. I'm mostly curious what causes the shudder and why my performance clutch is seemingly worse than OEM.

Performance clutch??

Was the flywheel brand new? It sounds like there is something wrong with the new clutch or flywheel if it's holding less torque than the stock one...

I've never heard of a Sachs performance clutch, do you know the specific part #s used and what engine it was made for?

On any performance diesel it's best to downshift instead of flooring it at low RPMs. The slower the transmission is spinning the more load it will experience from a high torque input. Same goes for crank walk and cylinder pressures (to an extent).

Have about 2 years @ 380wtq by 2400rpm in a DSG mk6 and it's been holding together fine, but I'm sure if I floored it at 1500 in 5th and 6th all the time forcing drivetrain shudder in manual mode I'd be able to break it.

The torque was causing drivetrain problems so it was reduced, adding it back in won't help but top end power can be kept the same. Welcome to reach out to us at info@malonetuning.com. mark sent a tune a couple days ago. Sorry but hard to tell what's going on without having the vehicle in front of us, but this isn't a common problem and cr190 hybrids are making another 30lb-ft to the wheels by similar RPMs just fine.

Thanks for replies. Brand new sachs performance clutch/DMF from Darkside. The shudder I was experiencing was right around 2200rpm. The engine is smooth enough at 2200 in 5th and even 6th that it seems to me this should not be a problem, however I can accept that I may be wrong about that. I do feel strongly that a downshift when in 4th or 3rd to avoid shudder is not practical at 2200rpm. Again, was not getting this with OEM clutch.

3rd@2200 --> 2nd = 3500
4th@2200 --> 3rd = 3200
5th@2200 --> 4th = 2800
6th@2200 --> 5th = 2600


I did get the new tune installed and completely eliminated the shudder. Having to reduce torque is a bummer, but still pulls good starting around 2600. I can live with it if there's nothing that can be done.

I just can't wrap my head around the fact that I'm having more shudder with performance clutch/DMF than OEM.

there are MANY performance clutches ranging from light to heavy. all of them feel very similar. stage 1.5, 2, 3 and there are endurance versions of them as well. what exactly did you get.
IMO stage 3 is probably best for you.

in a nut shell, shudder is when the friction plate and the flywheel surface do NOT give out in friction but rather they skip around. think of it like this. your wiper blades when it rains. when they are new they slip and glide easily across the glass smoothly. this is exactly what a worn clutch does when it slips. Ever have your wipers skip around and make lines in the rain because there is not enough rain? THAT'S SHUDDER but its caused by various things from excess heat from abuse before brake in is done, too much power / resistance between them, its still giving out due to forces exceeding the clutch limits but its not slipping, its skipping.

Thanks for that explanation.

I do not know exact part number. He was originally going to go with southbend stage 2, but apparently was discontinued.

what local shop installed: "Sachs performance clutch rated for 405 lb-ft., SACHS performance DMF".

Mongler98 said:

there are MANY performance clutches ranging from light to heavy. all of them feel very similar. stage 1.5, 2, 3 and there are endurance versions of them as well. what exactly did you get.
IMO stage 3 is probably best for you.

in a nut shell, shudder is when the friction plate and the flywheel surface do NOT give out in friction but rather they skip around. think of it like this. your wiper blades when it rains. when they are new they slip and glide easily across the glass smoothly. this is exactly what a worn clutch does when it slips. Ever have your wipers skip around and make lines in the rain because there is not enough rain? THAT'S SHUDDER but its caused by various things from excess heat from abuse before brake in is done, too much power / resistance between them, its still giving out due to forces exceeding the clutch limits but its not slipping, its skipping.

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Dude. You are totally wrong again. In this thread we are talking about Dual Mass Fllywheels. Not clutches. Totally different.

When you say shudder what do you mean by that?

"I do feel strongly that a downshift when in 4th or 3rd to avoid shudder is not practical at 2200rpm."

And there's the problem, the operator. Owain has hit the nail on the head,
not enough revs when asking for max torque. You want to be in the high
2k rpm range when you punch it. It's the same phenomena in the ALH
when folks blow out 5th gear. Take the motor to 3800 EVERY shift, per
TdiMeister, you are NOT hurting the engine.

Learn to drive a diesel, they don't like lugging. I've got a similar problem
with my "new" Jeep CRD, the auto tranny torque converter can't handle
low revs and shudders, shift points are too low for the torque. Shift the
transmission, rev it out a bit more, and no problem.

I have never had a shudder on any of my diesels due to the fact Russell posted above. I rev then every time I drive. Sometimes I hit limiter but why not? Atleast I know I’m always feeding oil to my main bearings good.....hint hint

There's no problem with running the engine at low revs as long as you don't request a lot of power from those low revs. I frequently run my ALH at 1400 RPM in 5th, but unless I'm accelerating VERY gently I downshift before requesting power.

But at part throttle you should NOT have shudder at 2200 RPM. If you do something's amiss.

IndigoBlueWagon said:

There's no problem with running the engine at low revs as long as you don't request a lot of power from those low revs. I frequently run my ALH at 1400 RPM in 5th, but unless I'm accelerating VERY gently I downshift before requesting power.

But at part throttle you should NOT have shudder at 2200 RPM. If you do something's amiss.

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Turbo and tune dependent. I can drive my 17/22 at 1400rpm, but usually
downshift 1800-2000, passing? I want be in the 3000rpm + range if I'm
hammering it. A lot of this depends on driving style, and expectations.
Work with your motor, rather than trying to work it.

It's not a gasser, adapt!

beechfront said:

Thanks for replies. Brand new sachs performance clutch/DMF from Darkside. The shudder I was experiencing was right around 2200rpm. The engine is smooth enough at 2200 in 5th and even 6th that it seems to me this should not be a problem, however I can accept that I may be wrong about that. I do feel strongly that a downshift when in 4th or 3rd to avoid shudder is not practical at 2200rpm. Again, was not getting this with OEM clutch.
3rd@2200 --> 2nd = 3500
4th@2200 --> 3rd = 3200
5th@2200 --> 4th = 2800
6th@2200 --> 5th = 2600
I did get the new tune installed and completely eliminated the shudder. Having to reduce torque is a bummer, but still pulls good starting around 2600. I can live with it if there's nothing that can be done.
I just can't wrap my head around the fact that I'm having more shudder with performance clutch/DMF than OEM.

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I have the same setup, the flywheel is just a stock Sachs unit. There does not exist any "beefy" DMF unfortunately. I would get shudder with it as well, but detuned so the torque ramped up just under that threshold. If you ever travel down a path to upgrade the turbo, just go bigger so that peak torque comes after 2400rpm and you don't have to detune
I'm pleasantly surprised at how driveable a 2260 turbo is, and clutch holding just fine...imagine I should be around the 360ft-lbs range at the moment.

Rev it out like a turbo civic

Rrusse11 said:

Turbo and tune dependent. I can drive my 17/22 at 1400rpm, but usually
downshift 1800-2000, passing? I want be in the 3000rpm + range if I'm
hammering it. A lot of this depends on driving style, and expectations.
Work with your motor, rather than trying to work it.

It's not a gasser, adapt!

Click to expand...

I did tend to keep revs higher when I had the 17/22 and RC6. That turbo didn't like to spool below 2000 RPM, even in 3rd. It's one of the reasons I sacrificed some power and switched back to a VNT-15. And just now driving home my low fuel light came on at 760 miles, so I'm happy with that choice.

The 15 will spool instantly even at 1500 RPM in 5th. But I still wouldn't hammer it at those revs.

You've clearly adapted to what you want, and living with the trade offs.
Me, I just got 42mpg 90% hwy. I'm happy with that with winter fuel.
And it's a rare occasion to come even close to WOT.

Rrusse11 said:

Me, I just got 42mpg 90% hwy. I'm happy with that with winter fuel.
And it's a rare occasion to come even close to WOT.

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I switched back to the milder setup for several reasons, not the least of which I didn't want to swap out rods in a brand new factory long block. But I rarely, if ever, could use all the power the old setup made on the road. On the track it was a blast, but those days (at least in this car) are behind me.

I filled the car when I got home today. 49 MPG on winter fuel, with snows on the car. Down from 50 even on my last tank. A lot of that is commuting at 75=-85 MPH. I don't mind that, either.

17/22 MK4s on smokey tunes are notorious for putting diffs through housings, wrecking 5th gear, and even wearing out alh rods over time. Meanwhile they're making another 50+hp in Europe revving them to the moon on stock rods.

Seems to vary a lot on the mk6/7 for shudder, ~95% of cars are fine on normal "stage 2" tunes, some if you lug them they'll shudder. Either have to give up some bottom end in every gear, tune by gear, or go by customer, mostly go by customer preferences so that the vast majority can enjoy it. The EA288s seem a little less tolerant, smoothing the powerband also leaves more room for EGTs and boost control up top, but you can lose some response banging through the gears.

This is around the limit on a CJAA, gtb1756 stage 4 kit

https://i.gyazo.com/a38d899b49e41c2f31e5663dd3241f88.png

and EA288, stock turbo along with xman cr190 hybrid (bottom line being stock)

https://i.gyazo.com/d06e56afce61bf7ebc36a523e1ee35fe.png

Both of these are DSG, both were at the point of a tiny bit of shudder during spool up, manuals behave fairly similarly but we can't tune trans to avoid it. Tapering to around 280lb-ft peaking at 2500 allows for a tiny bit more fuel up top (5whp tops) and feels a little bit quicker since it's not as punchy down low.

Owain@malonetuning said:

17/22 MK4s on smokey tunes are notorious for putting diffs through housings, wrecking 5th gear, and even wearing out alh rods over time. Meanwhile they're making another 50+hp in Europe revving them to the moon on stock rods.

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In fairness, I drove my Wagon 120K miles with the 17/22 in it and RC6. Lots and lots of track days. I used all of the revs frequently: I'd go till the tach stopped at 5400, count to three, then shift. It was useful on the track because it often meant not having to shift again: I could get 80 out of 3rd and 115 out of 4th. Engine ran great when we pulled it apart at 280K miles, but all the rods were slightly bent and the valve guides were so worn that you could wiggle the valve stems. Bores were ovaled and it was blowing a little oil. But the turbo and tune worked beautifully. It was another setup for another time, however. I love the setup I have now.

I've got ~40k on my 17/22, IQ dialed right back, the barest trace of smoke
at WOT. I don't push it, no need. Guessing 160hp/280'#s, and that's plenty for me,
no track and the rev limiter in place. My feeling is that the setup will easily
take another 100k (183k now) without blowing the engine.

Drive it with reserve, keep up the maintenance, and don't push the limits,
fingers crossed it'll keep on running. Body and paint are good.
Great GT car, sits at 80 at 2600rpm.

Well thanks everyone for all the replies and great info. Seems I must concede that I need to rev the thing out a bit more.
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Don't think I would have encountered the shudder very often in real-world-driving but the feeling that something might not be right is what prompted me to start asking questions. I still don't fully understand why my performance DMF seems to suffer from shudder worse from OEM - but as long as the shudder was a result of my driving and not an issue with the new clutch/DMF setup - I can move on.
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Drove the car quite a bit yesterday and I think latest tune from Malone is probably ideal for the car. The spike at 2200 is gone and still pulls as good as it previously did (or better?) past 2600. Malone team is great.
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Been very impressed with the power & fuel economy from this car. A far cry from the mid-80's diesel pickups I grew up around. I think GM just took a 350 gasser and converted to diesel for a period of time...? Those things were gutless.

beechfront said:

Well thanks everyone for all the replies and great info. Seems I must concede that I need to rev the thing out a bit more.
-
Don't think I would have encountered the shudder very often in real-world-driving but the feeling that something might not be right is what prompted me to start asking questions. I still don't fully understand why my performance DMF seems to suffer from shudder worse from OEM - but as long as the shudder was a result of my driving and not an issue with the new clutch/DMF setup - I can move on.
-
Drove the car quite a bit yesterday and I think latest tune from Malone is probably ideal for the car. The spike at 2200 is gone and still pulls as good as it previously did (or better?) past 2600. Malone team is great.
-
Been very impressed with the power & fuel economy from this car. A far cry from the mid-80's diesel pickups I grew up around. I think GM just took a 350 gasser and converted to diesel for a period of time...? Those things were gutless.

Click to expand...

Yes, TDI's are great little engines.... good economy , reliability, and power with a little tweaking...

Our family had three cars with the 5.7 GM diesels...

The 81 caprice could get 22 to 24 mpg highway which was crazy good for a full sized car back in the day...

Power wise it was a factory coal roller!

Yes you could floor it , the tranny would unlock and or drop a gear, and you'd put down a smoke screen that would cause other cars to back off .... or go around you ...

Yes go around , because even though you were laying down a fog of coal , on steeper grades (at highway speedsl) dropping a gear and flooring it still often resulted in losing speed so we were easy pickings for gassers to blow by us .... the hills were our enemies!

Reliability wise 5.7s went through injection pumps glow plugs and head gaskets ... sigh

Performance they could spin tires if the injection pump was advanced !

One time, after having an injection pump replaced at the shop, they must not have had the timing on the pump set correctly (over advanced) .... omg the car felt way different.... tires could be spun at will! Wow the power.. .

On the flip side the head gasket only lasted about 20 miles after that so it was expensive fun! :-0

Dad replace the engine on that car with another diesel engine which worked for a really long time until it developed a rod knock and the car was sold at which point and dad bought a diesel station wagon because by that point I myself had a diesel station wagon and he wanted more space...

Yes we were gluttons for 5.7 diesel punishment !

I think it was the false economy of getting great fuel economy ( false economy because it was expensive having injection pumps and head gaskets replaced ) but the fun of rolling coal that was the big selling point for us...

Yeah greta we dared and did roll coal ! ;-)

In time, although not many miles , dads 5.7 diesel blew one too many repair budgets and it was ultimately swapped out for 403 olds gasser .... yeah we went big with the small block !

In time the diesel wagon I had blew either another head gasket or injection pump and being tired of the constant repairs I bought a regular gasser...

Come to think of it my sister actually had a V6 diesel celebrity size car at one time .... yeah they made those too for a bit!

Wow the good old days of early diesel GM cars .... brings back memories ....

Andrew

beechfront said:

I still don't fully understand why my performance DMF seems to suffer from shudder worse from OEM

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That's because the so-called "DMF shudder" is caused by the engine, NOT the DMF.

(and sometimes CV joints/axles or other mechanical issues, but NOT the flywheel.)

IndigoBlueWagon said:

I did tend to keep revs higher when I had the 17/22 and RC6. That turbo didn't like to spool below 2000 RPM, even in 3rd. It's one of the reasons I sacrificed some power and switched back to a VNT-15. And just now driving home my low fuel light came on at 760 miles, so I'm happy with that choice.
The 15 will spool instantly even at 1500 RPM in 5th. But I still wouldn't hammer it at those revs.

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Are you running RC3 on a VNT 15? I am looking at your signature and it appears to be the case.

NewTdi said:

Are you running RC3 on a VNT 15? I am looking at your signature and it appears to be the case.

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Absolutely, on both my Wagon and '99.5 Golf. The Wagon has 3+, with 19.5 PSI max boost. Engine got a new Mahle turbo when I replaced the long block, and it's been working fine for the last 115K miles.

IndigoBlueWagon said:

Absolutely, on both my Wagon and '99.5 Golf. The Wagon has 3+, with 19.5 PSI max boost. Engine got a new Mahle turbo when I replaced the long block, and it's been working fine for the last 115K miles.

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What other supporting mods do you have? I am intrigued by RC3+ and VNT15. I bet the spool and acceleration is quite nice.

I've got a bunch of mods, some of which are leftover from running a 17/22 and RC6, but they probably help: lift pump, 11mm pump, PP357s, PD150 snorkel, airbox, airbox to intake, and intake manifold, larger SMIC, 2" stainless downpipe w/o CAT. Spool is pretty amazing, as is the FE.