Help from those with single mass flywheel

calvR

Active Member
Oct 21, 2011
392
2
Kent
I know im asking a very limited audience here, but ive had my sachs/ loba stage 2 clutch and flywheel for a few months now. The pedal feels great, the gear change is fine and smooth, it engages fine isn't too far off oem in that respect. But its extremely noisy on over run. If I let the throttle off at any revs it sounds like there's nuts n bolts going around inside my engine. It's not too bad at low revs and most people dont notice it when im driving normally, pick up the pace however and let off at high revs in say 2nd or 3rd gear and its loud. Does anybody else have similar experience with an smf? There's no rattle at idle and no noise on acceleration, just on overrun.
 

Al

Active Member
Aug 29, 2005
7,326
9
Sounds normal (and horrible).

I swapped out my Southbend kit for a Sachs and OEM dual mass flywheel and wish I never bought the Southbend. Gear changes are loads better with the Sachs/Dual mass too.
 

Marshall

Active Member
Jul 7, 2008
3,256
6
Bonnie Scotland
I've never owned a car with a smf fitted but drove a few.
As Al says about normal I'd say!
I've never been a lover of smf due to the extra stress on the crankshaft.
 

AndrewJB

Friend to SEAT UK & Cupra Racing
Aug 16, 2007
11,175
485
Maranello
My Southbend dont do this on the 2.0tfsi but on the 2.0tdi it was noisy as hell

Sent from my GT-I9505 using Tapatalk 2
 

Adman77

Audre Est Facre
Feb 13, 2012
774
0
Hertfordshire
Can someone simplify the difference between a single and a dual for me please?

And what's the pros and cons of each?

(I'm sure this will benefit a few people actually :D)
 

calvR

Active Member
Oct 21, 2011
392
2
Kent
So it sounds like its normal then so that's good. I must admit the only noise I was aware of wen I decided to go with smf was the rattling everybody seems to mention. Nobody really said anything about the sound resembling a chainsaw on overrun.
I'm ok with the noise as its not actually a problem on the daily drive, my wife never mentions it and she drives it everyday to work. It just sounds awful when slowing for corners when on track or fast road driving. I always rev match on downshifts and heel and toe so hopefully the crank and gearbox won't get too much stress, although obviously more than a dmf I realise
 

Seatmann

Rough around the edges
Sep 16, 2010
5,575
10
Scotlanda
If it's a 6spd box then they're always extra loud with the smf apparently, also a lot of people tend to fit a lightened flywheel which just exacerbates the problem.
 

JayCee

Active Member
Apr 8, 2010
236
0
Isle of Man
Mines never bothered me - only really notice slightly more vibration up to ~1750rpm. Can't say I have ever noticed it on run off (too much engine and road noise?!)
 

calvR

Active Member
Oct 21, 2011
392
2
Kent
Can someone simplify the difference between a single and a dual for me please?

And what's the pros and cons of each?

(I'm sure this will benefit a few people actually :D)

Well basically a dual mass is 2 separate plates with springs in between them. The springs have a damping effect between the engine and gearbox so it smooths out noise, vibration and harshness (NVH). The problem is the springs wear out causing excess movement between the 2 plates, in the worst case they can fail completely causing a lot of damage.
A single mass is a solid plate so a lot lighter but all the nvh is transmitted straight through the gearbox and into your arse and ears :D
They can handle the torque a lot better than a dual mass and u get instant clutch engagement as there is effectively no slack in the drivetrain. They dont wear out like dual mass as there is nothing to wear.
The big problem is that due to the lack of damping effect they are noisy and the vibration from the engine is transmitted straight through the gearbox and back through the crank. This could cause problems later on although I think the way you drive will have a big effect on this. If you slam your shifts home and dump the clutch up it will bang right through the car, so some mechanical sympathy is definitely required.
 

calvR

Active Member
Oct 21, 2011
392
2
Kent
If it's a 6spd box then they're always extra loud with the smf apparently, also a lot of people tend to fit a lightened flywheel which just exacerbates the problem.

My loba is just under 5 kgs lighter than the oem dmf. I thought all smfs would be lighter anyway?
 

Seatmann

Rough around the edges
Sep 16, 2010
5,575
10
Scotlanda
Mine's about the same weight if not a little heavier, I think it's 22lbs there abouts. Lucky for me though I'm on the 5spd box so can use the sachs VR6 kit with the standard G60 flywheel.
 

Adman77

Audre Est Facre
Feb 13, 2012
774
0
Hertfordshire
Well basically a dual mass is 2 separate plates with springs in between them. The springs have a damping effect between the engine and gearbox so it smooths out noise, vibration and harshness (NVH). The problem is the springs wear out causing excess movement between the 2 plates, in the worst case they can fail completely causing a lot of damage.
A single mass is a solid plate so a lot lighter but all the nvh is transmitted straight through the gearbox and into your arse and ears :D
They can handle the torque a lot better than a dual mass and u get instant clutch engagement as there is effectively no slack in the drivetrain. They dont wear out like dual mass as there is nothing to wear.
The big problem is that due to the lack of damping effect they are noisy and the vibration from the engine is transmitted straight through the gearbox and back through the crank. This could cause problems later on although I think the way you drive will have a big effect on this. If you slam your shifts home and dump the clutch up it will bang right through the car, so some mechanical sympathy is definitely required.

Perfectly explained calv, thank you!! So I'm guessing the springs on a dmf aren't exactly a serviceable part then? And what sort of problems would all the nvh going through the crank cause with the smf?

Always strughled to grasp all the ins and outs of a clutch :D
 

calvR

Active Member
Oct 21, 2011
392
2
Kent
Perfectly explained calv, thank you!! So I'm guessing the springs on a dmf aren't exactly a serviceable part then? And what sort of problems would all the nvh going through the crank cause with the smf?

Always strughled to grasp all the ins and outs of a clutch :D

Well potentially breaking it but I've only heard of it happening on a diesel car. I believe its due to the high torque and much higher nvh of a diesel engine.
I dont think dmfs are serviceable, replacement is the only way I think
 

POPOV

Newbie
Jun 25, 2005
581
2
Sweden
The noise is a result of the modification you have done. Drive pass someone that knows that noise and they will know you have mounted a single mass flywheel =).
 

richicupra

Active Member
Jan 29, 2012
1,823
9
Sounds normal (and horrible).

I swapped out my Southbend kit for a Sachs and OEM dual mass flywheel and wish I never bought the Southbend. Gear changes are loads better with the Sachs/Dual mass too.

Where did you get this done mate? Is the OEM DMF OK for stage 1 cars?
 

m.001

Active Member
Oct 1, 2012
149
0
I know im asking a very limited audience here, but ive had my sachs/ loba stage 2 clutch and flywheel for a few months now. The pedal feels great, the gear change is fine and smooth, it engages fine isn't too far off oem in that respect. But its extremely noisy on over run. If I let the throttle off at any revs it sounds like there's nuts n bolts going around inside my engine. It's not too bad at low revs and most people dont notice it when im driving normally, pick up the pace however and let off at high revs in say 2nd or 3rd gear and its loud. Does anybody else have similar experience with an smf? There's no rattle at idle and no noise on acceleration, just on overrun.


I am glad I spotted this thread, I have had my stage 2 loba/sachs clutch and flywheel now for about 3000KM and it all works perfectly (so far) but I have the same noise in over run and had never heard anyone talking about it while I was doing all my research for a new clutch. As you said everyone only ever seems to talk about the slight rattling or chatter when the clutch pedal is not engaged etc..
This has now put me at ease.. Didn't realise however that it puts extra stress on the crank.. oh well, I guess there are always a few compromises here and there. I'll just try drive sensibly and smoothly when I am not on track.
 
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