# Brake Disc vibration, replaced but still a problem: on car disc skim advice?



## Irish Phaeton (Sep 6, 2010)

I had the discs replaced by VW UK & my VW garage a few months ago (V6 TDI) , car was close to 3 years and ~50K miles. There was a slight cyclic vibration/ pedal pressure on braking, not easy to detect, but from once you knew it was there it was annoying. I was not convinced the replacement was 100% successful, but it was not until I had 4 new tyres fitted and all rebalanced last week that I could clearly see that I still have the problem, maybe even worse than before the discs were replaced.
2 Queries
•	Is there anything else that can cause the same brake pedal feel, other than a warped disc: a bend in a suspension component or the like? I query this as I bent an wheel last year in a huge pothole and wondered if this could have damaged something
•	I have found a local company with an on-wheel disc skimming machine that I understand can be excellent to resolve these issues. Maybe this would be the way to go.


Many thanks
Hugh
Dublin (Ireland)


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## dlouie (Oct 31, 2008)

Hugh,
I'm not sure if you mentioned if all four discs were replaced. If all four discs were, I can see no reason why you would machine them. Before you do, I would have the runout on both surfaces of each disc checked while the discs are on the car. 

On another note, my Porsche had a bad vibration. I had all wheels balanced off the car. That did not solve it. Then I had the wheels balanced on the car which did solve it. Apparently, the imbalance was in the entire rotating wheel assembly which includes the disc. This also meant that each wheel now had to be mounted in the same position and location. 

Worn suspension components can cause shimmy but it doesn't sound like that is what your describing. The wheel shimmy I've experienced usually happens at a certain speed and the effect is reduced when the brakes are applied.

Good luck,

Damon


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## Irish Phaeton (Sep 6, 2010)

*Discs*

Damon, as best I am aware, front discs only replaced; should have mentioned this as it had occured to me this might be a factor. I guess one one feel the pressure in the pedal irrespective of the ofending disc.

Damon
thanks for the video link. I have located a local workshop with the technology to measure this and will have it done in the next few days. Will report back.
Hugh


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## dlouie (Oct 31, 2008)

Hugh,
How long has it been since the installation? Have you "bed" the pads in? You should still measure the runout for all the rotors.


Here is a video showing the process:

http://www.youtube.com/watch?v=H_1ySs7liS4&feature=related

I say take a reading on both sides to check if the braking surfaces are parallel. This should be carefully done. Sometimes the excessive runout is contributed by the hub so no matter how perfectly the rotors is machined, you will still get runout. Sometimes it can be corrected by shims. Some say a runout of 0.002" is the limit. VW may have a spec for runout.

Damon


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## jpett (Nov 9, 2009)

HI Hugh,

Strangely I have the same issue with my Phaeton and I’m only up the road from you, is it possible I hit the same pot hole? Bad pads may also cause this type of vibration or pads coming close to replacement, but I’m presuming VW UK checked both front and rear at the time? 
I have new pads ready for mine, I’m praying it’s not the front discs! To be honest I’d rather replace a bad disc than skim on such a heavy car. You may find the issue returning after a few thousand kilometres.

Look forward to your update.

Regards 
James


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## Irish Phaeton (Sep 6, 2010)

I know this is an old post, but just to give the end game: Apparently VW must not have checked the rear discs when replacing the front. I had the rear discs replaced (by a non VW workshop) and this solved the vibration problem. In hindsight I think the brake components on the V6 tdi are fairly standard VW/ AUDI parts and "relatively" inexpensive to replace. 

PS. The pothole was in Tipperary, on a side road off the old N7, and truly the mother & father of all holes. A testament to the build of the VW that we emerged with no other damage...
Hugh



jpett said:


> HI Hugh,
> 
> Strangely I have the same issue with my Phaeton and I’m only up the road from you, is it possible I hit the same pot hole? Bad pads may also cause this type of vibration or pads coming close to replacement, but I’m presuming VW UK checked both front and rear at the time?
> I have new pads ready for mine, I’m praying it’s not the front discs! To be honest I’d rather replace a bad disc than skim on such a heavy car. You may find the issue returning after a few thousand kilometres.
> ...


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## Jorgsphaeton (Sep 8, 2009)

same problem here. changed rotors,pads,bearings tires and afterall changing the control arm bushings solved the problem.
jorg


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## PanEuropean (Nov 3, 2001)

Irish Phaeton said:


> ...The pothole was in Tipperary, on a side road off the old N7, and truly the mother & father of all holes.


Hi Hugh:

I think I went by that pothole a few years ago when I took my motorcycle to Tipperary to do some research on my ancestors (all of whom are from Ardfinnan).

I remember driving past a pothole and looking down into it, there was a tow truck and a phone booth at the bottom of the pit...

Anyway, about the brake vibration, I concur with Damon's suggestion that you check the runout on the discs first, before having any machining done. The discs are relatively thin, and are not intended to be put on a lathe.

Below is a photo showing how I do runout measurement on my Phaeton.

Michael

*Runout Measurement *


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## vinyin (Feb 28, 2010)

I have a similar problem when reaching 80kmh (50mph) and then again at about 110kmh (68mph) with three different sets of tyres - one set was balanced 3times. 

Thats Vibration which feels like the whole car is shaking - when driving alone the headrest of the passenger seat is even shaking. 
The vibration isn't when braking - it seems actually less when braking - it's without brakes applied. 

Another thing is that after changing all wheels (second winter set) the ride was vibration free until I had to brake quite heavily. Then it started again. 

My dealer noticed that my brakes are worn and should be replaced - front+rear with disks. 
Might that be a cause?


Might that solve that problem?


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## wouterjansen60 (Aug 27, 2011)

Jorgsphaeton said:


> same problem here. changed rotors,pads,bearings tires and afterall changing the control arm bushings solved the problem.
> jorg


Same as Jorg, upper controlarms, bushings, front bearings and disks renewed and similar problem was solved ( it took the dealer a year to sort out. All under warrenty except the controlarms and bushings. Km 120k.

Cheers, Wouter


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## vinyin (Feb 28, 2010)

I got the discs and pads front and rear replaced today - the problem with the vibration beginning at 70kmh persists. 

What did the replacement of the controlarm bushings (Querlenkerbuchsen) cost?


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## wouterjansen60 (Aug 27, 2011)

vinyin said:


> I got the discs and pads front and rear replaced today - the problem with the vibration beginning at 70kmh persists.
> 
> What did the replacement of the controlarm bushings (Querlenkerbuchsen) cost?


Hi,
And dont forget the front wheel bearings... If this the case..

Controlarm ( upper) replacement and some bushings is around 7h work, so calculate with local rates.
Wouter


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## invisiblewave (Sep 22, 2008)

Probably need an alignment, too, after changing control arms. I think the cost on mine was about $1700 part & labour, not including the alignment (which they neglected to charge me for and usually costs around $300).

The other thing you might think about before spending that kind of money is the transmission. There are various threads here about vibration caused by a transmission problem. If it were the wheel bearings, I'd expect there to be noise as well. My failing rear bearing produced a hum that got steadily worse with time.


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## dlouie (Oct 31, 2008)

Another cause of vehicle vibration can be attributed to worn rubber components in the suspension system and is known shimmy. It generally happens at a very specific speed range and can be calmed down by usually applying the brakes. In this case, it has nothing to do with unbalanced rotors, tires, and or wheels. Excess play in the suspension system and resonance amplifies the vibrations. A highly publicized issue with Jeeps called the "Death Wobble" is a similar example of what shimmy is. Bad bearings will not cause this unless they are really bad. Symptoms of a bad bearings generally produce grinding or humming noises that change when the weight of the car is shifted.

Damon


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## wouterjansen60 (Aug 27, 2011)

dlouie said:


> Another cause of vehicle vibration can be attributed to worn rubber components in the suspension system and is known shimmy. It generally happens at a very specific speed range and can be calmed down by usually applying the brakes. In this case, it has nothing to do with unbalanced rotors, tires, and or wheels. Excess play in the suspension system and resonance amplifies the vibrations. A highly publicized issue with Jeeps called the "Death Wobble" is a similar example of what shimmy is. Bad bearings will not cause this unless they are really bad. Symptoms of a bad bearings generally produce grinding or humming noises that change when the weight of the car is shifted.
> 
> Damon


In my oppinion its wise not to exclude unusual solutions. I wrote before about the wheel baering change under warrantee did solved my vibrating problem after renewal 3 times new disks etc. Agree, most expect bearings to first to be noisy or have notible excesive play, but that was not the case at my car. A renewal under warrantee did solved all problems. Of course, vibration can have many reasons and is not so easy to determn were it comes from. 
Cheers, W


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## vinyin (Feb 28, 2010)

Thank you all guys for your suggestions. 

When it would be a problem with the trany then I guess the vibration would change when logging into that speed (gra) where the vibration is the most and then downshifting or putting it into neutral. But the vibration is still there. 

When the vibration occurs there is no strange sound. 



> Today 08:13 PMdlouie
> Another cause of vehicle vibration can be attributed to worn rubber components in the suspension system and is known shimmy. It generally happens at a very specific speed range and can be calmed down by usually applying the brakes.


That sounds close to the problem I'm experiencing. Do you think that if that would be the case this could be seen / diagnosed before replacing anything?


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## cai (Mar 22, 2009)

I reported on a similar vibration some weeks ago. I had the tires rotated and then the vibrations started at between 55 and 65 mph. The shaking also happens when going at a higher speed and I apply the brakes and reach 65 mph. The right side upper bushings were replaced and I am going to do the left side on my own soon. I also have a grinding sound when I turn the steering wheel while stationary. The grinding sound seems to be worse when it gets really cold outside, lower than 32 degrees F.

The tech has said nothing about wheel bearings and I am going to ask about any transmission issues next time I go to the dealer. I am looking at rotating my tires every 7,000 or 8,000 miles, so I am about 1,500 miles away now. Lets see what happens after I do that around November or so. By then I would have replaced the left bushings also.

cai


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## dlouie (Oct 31, 2008)

Worn suspension bushings can be hard to diagnose even if they are not visually deformed. The rubber can soften and not look bad even when displaced with a pry bar. Most technicians check bushings by prying on the control arm to see if they have excessive movement. This is purely subjective. No measurements are taken. With the heavy weight of the Phaeton the bushings are probably pretty substanial and even when soft, may appear to be ok when checked by prying in comparison to lighter weight cars. The rubbers can just get soft enough to create a resonance in the suspension system at specific speed ranges. The resonance usually appears at a certain speed; then goes away only to reappear at another speed. This is also known as shimmy which may not be attributable to the failure of one part. Tires, Wheels (balance and offset), control arm bushings, ball joints, etc. all all affect the harmonics of the suspension system. Think of the Tacoma Narrows Bridge failure.

Imbalanced tires, wheels, and or rotors I believe will vibrate consistently at all speeds.

Vibrations and pulsation in the brake pedal are usually caused by warped rotors.

Grinding noises at all speeds that change when the weight of the car is shifted are usually caused by bad wheel bearings.

Grinding like noises when the car is stationary and the steering wheel is turned is usually air in the power steering system (cavitation) or starvation fluid to the steering pump.

These are just my 2 cents.

Damon


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## vinyin (Feb 28, 2010)

I did get new brakes all around - discs and pads. Didn't change anything about the vibration at all. 

I also got 4 new wheel bearings - again no difference. And all wheels (3sets  got balanced several times. 

Since I can't stop noticing the vibration - I did get to record the front suspension while driving for diagnostic purposes. 
The first video shows the front left suspension without any noticeable problems. 
http://youtu.be/SoCuQK94-pk

The next video shows the front right suspension - there is a noticeable wabble from the driveshaft on the wheel side. 
http://youtu.be/_OW3zcameDQ

When inspecting the driveshaft there is quiet a lot of play from the driveshaft on the gearbox side which doesn't seem normal. The other side is tight. 
http://youtu.be/yM87-3WDWU4

The front right driveshaft could explain a different symptom. 
The car pulls slightly to the right (the car got alignment by vw several times without difference) except when the car is set to the high ride height. 
My theory is that when the car is set to be in the "high setting" it's more unlikely for the driveshaft to get pulled outwards to the wheel (because of that play) due to the different angle of the driveshaft (like seen in the first few seconds in this video --> http://youtu.be/-KY56CwW58M )

Is any of this plausible??


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## invisiblewave (Sep 22, 2008)

I can't shed any light on the problem, but that's some great video! How did you manage it?


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## vinyin (Feb 28, 2010)

invisiblewave said:


> I can't shed any light on the problem, but that's some great video! How did you manage it?


I used a mobius 1080p wide angle car cam. I usually use it for car surveillance to record from behind the windshield. 
I used a generic mount that came with the camera and put some temporary protection on it. Luckily the camera survived  actually it was a very solid mount to my surprise....


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## PanEuropean (Nov 3, 2001)

vinyin said:


> I did get new brakes all around - discs and pads. Didn't change anything about the vibration at all.
> 
> I also got 4 new wheel bearings - again no difference. And all wheels (3sets  got balanced several times.


Hi Vinyin:

I'm not much of a suspension expert, but I can share an experience I had with my motorcycle several years ago: I normally replace the tires on the motorcycle twice a year (they only last for about 5,000 km). Once, after replacing the tires, I noticed that the front tire was out of balance the first day of riding. I took the moto back to my Swiss moto dealer, who checked the front wheel balance both dynamically and statically, and advised me that the wheel was "perfectly balanced" according to the results of both tests. I told the dealer that despite his findings, the wheel was out of balance when I rode the moto. His comment was "Ah, in that case, the new tire must be defective". He then replaced the front tire (which only had perhaps 50 km on it) with a new front tire, balanced it again, and the result was perfection. 

The moto dealer was quite happy to do this, he told me that every so often - perhaps 1 out of 100 tires - this kind of thing happened, and that the tire company would give him credit for the problematic tire.

So, relating this to your problem, could it be possible that there is a defect with one of your tires? How old are the tires, how much life do they have left? Are they the correct specification of tire (size and weight rating) for your vehicle?

Michael

*PS:* We would all be grateful if you would take a look at the request made in this post: Please Read - Regarding your Forum Profile and fill in your first name, location, and vehicle year & engine type.


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## vinyin (Feb 28, 2010)

Hi michael,

I'm pretty sure it's not the tyre that's causing the vibration since it's the same with three different sets. One set brand new Pirelli. 
Using the set of wheels seen in the video - I changed the rear wheel on the front - which didn't change the vibration of that front right wheel. 
I use original VW phaeton rims which are fine with correct sized tyres. 
235/55r17 inspiration - Pirelli 
245/45r19 Serres - Pirelli 
255/40r19 Helios - Yokohama
As said before - all are balanced several times - all are fine. 

I did actually had one time a faulty set of hankook tyres - way more vibration. 

,Michael


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