How to retro-fit the rear subframe harmonic damper from the Audi A3 Saloon (2013->)

[anotero]

Order from e-acca, will come to about $70 shipped if you aren't in a hurry...

THIS. I already placed an order with them, just need to pay.

 

[DSC808]

Good stuff. Will have to do this sometime.

 

[golfdave]

How do I make the torsion beam quieter ?

Earplugs???...

Or fit some of the plastic "rough road" protector trays made to attach to the torsion beam..in my big thread "how to retro-fit the aerodynamic undertryas"..

 

[riceburner]

Order from e-acca, will come to about $70 shipped if you aren't in a hurry...

Thanks!

 

[donefor]

Great information, thanks golfdave!

 

[quailallstar]

This is next on the mod list for the 19 GTI!

 

[ReadTheBook]

Great sleuthing! Thanks Dave!

Ordered from e-acca.

 

[Navi]

I'm still waiting on mine from EACCA

but your review gives me hope. My car is so god damn stiff. I hope that thing takes up some of the vibrations.

 

[Roadhog]

Nice research! Would this be possible on a R?

 

[golfdave]

Nice research! Would this be possible on a R?

Nope.....totally different subframe design to hold the Haldex AWD unit...

 

[Roadhog]

Thanks! I could have just poked my head under the car and seen myself i guess.

 

[JD-1]

Any videos of what the rear sounded like before doing this mod?

 

[golfdave]

Any videos of what the rear sounded like before doing this mod?

I haven't..there is this thread here & the OP did record the sound..

http://www.vwgolfmk7problems.uk/

 

[fuelboss]

With regard to the fitting of this "harmonic damper" or "balance weight" as Audi refer to it, it has nothing to do with the knocking noise or "rolling log" noise experienced by many owners, particularly on earlier MK7's as that noise originated from the original Sachs shock absorber issue that I have detailed many times on the forum and on my website www.vwgolfmk7problems.uk. That noise came from the shock absorber piston rod having too much play in the barrel. This noise was proven by changing to the Bilstein B4 dampers or indeed any other suitable replacements. In 2015 I discovered the issue and switched to Bilstein and I had no further issues with a knocking noise. In 2018 I purchased a MK7.5 GTI and not surprisingly the knocking noise was also apparent to some extent on that model. After changing to a pair of Koni Active's the problem was eliminated.

I am grateful to the person who came across this "harmonic damper" and given the hollow, drumming and irritating noise from the rear of my car, despite a change of tires along with fitting sound insulating I will be fitting this damper in the hope that it will improve my current issue. I have to say that if anyone has the knocking noise issue then I cant see that this damper will resolve that problem but it will be interesting to see if it improves the level of what I feel is intrusive cabin noise, that particularly for me is an issue over any surface other than super-smooth tarmac.

I have mentioned a year or so ago that last year I had the opportunity to test a 1.5TSI GT for quite a while. The intrusive sound from the rear of the vehicle was so bad that even the dealer, Bath VW in the UK agreed something was wrong and changed a wheel bearing but it made no difference so in my view the overall MK7.5 cabin noise is much higher than on the MK7 model. Interesting to know whether this damper would have improved that sound level from the rear endl!

Unfortunately I am away from the UK for 3 months so I will not be able to fit this damper until March so I am hoping others may in the meantime be able fit the item and comment on its effectiveness.

 

[golfdave]

With regard to the fitting of this "harmonic damper" or "balance weight" as Audi refer to it, it has nothing to do with the knocking noise or "rolling log" noise experienced by many owners, particularly on earlier MK7's as that noise originated from the original Sachs shock absorber issue that I have detailed many times on the forum and on my website www.vwgolfmk7problems.uk. That noise came from the shock absorber piston rod having too much play in the barrel. This noise was proven by changing to the Bilstein B4 dampers or indeed any other suitable replacements. In 2015 I discovered the issue and switched to Bilstein and I had no further issues with a knocking noise. In 2018 I purchased a MK7.5 GTI and not surprisingly the knocking noise was also apparent to some extent on that model. After changing to a pair of Koni Active's the problem was eliminated.

Just for added CLARITY.

I have the original factory Sachs dampers & they have passed 3 MOTs & even I can't find any problems with them & yet I had the "log rolling/hollow noise", therefore you can have perfect Sachs dampers but still have the noise.

Also swapping to the Bilstein B4s DOES NOT automatically guarantee eradication of said noise.
Quote from this forum:-

I spoke too soon!
2k miles since fitting the Bilsteins and the rumbling sound has gradually returned. I can only assume that gradual slight wear must take place in the seals etc.
Comments welcome!

https://www.golfmk7.com/forums/inde...r-suspension-again.330995/page-5#post-6840547

The main thing YOU should be thinking about is why did VAG design a Harmonic damper for the MK5 Golf rear multilink suspension (2WD),...There is a KNOWN harmonic resonance in the subframe/suspension design!!!

They ask yourself why did VAG give it a MK5 Golf part number, & then produce all the MK6 & MK7 Golf (& all other car variants eg Octavia/A3) rear subframes with the two mounting holes??…...Yet they only released the part on the current MQB Audi A3 saloon?? All to do with perceived quality...that car (A3) is up against BMW etc....so has to be as quiet as possible the other cars were "acceptable for NVH" according to VAG.

Regardless of you having faulty dampers, there is an inherent resonance in the rear suspension which I am 90% certain is created by the lower wishbones (due to the extreme angles of interaction & arc travel from the damper to top mount)....the Subframe "amplifies" this noise through the bodyshell.....By fitting the harmonic damper to the subframe at the intersection between the lower wishbones this stops the resonance dead in its tracks before it gets a chance to travel into the rear subframe/bodyshell...