Shaking steering wheel?

[vinnie83]

Trying to figure out what the problem is....

On hard braking, from a high speed (50+) I get a really bad shaking through the steering wheel...

Just got the car about a week ago, apparently had new discs + pads, however I suspect non OEM because they squeek to fk when I brake....

The juddering was not really noticeable when I got the car, but about 1500 miles later, when I brake hard the steering wheel judders violently..


Any advice?

Warped discs maybe? I looked at the discs and can't see anything out of the ordinary at all...

Car is a 2006 535d BTW

[tossbag]

Jack the wheel up and spin it by hand, look at the brake pad against the disc, you will see a wobble if it's warped.

[FasterFreddy]

Can you feel anything through the brake pedal or is it all coming through the steering?

[flemke]

Quite possible new brakes were not bedded in properly. A warped disc is extremely rare.

[goldblum]

Had same symptoms on my Audi.Garage replaced front discs and no more judder.They were warped.

[flemke]

goldblum said:

Had same symptoms on my Audi.Garage replaced front discs and no more judder.They were warped.

Unlikely that they were warped.
Fwiw:

technical source said:

...in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc.
In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

Much more detailed explanation here:

http://www.stoptech.com/tech_info/wp_warped_braked...

[goldblum]

flemke said:

goldblum said:

Had same symptoms on my Audi.Garage replaced front discs and no more judder.They were warped.

Unlikely that they were warped.
Fwiw:

technical source said:

...in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc.
In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

Much more detailed explanation here:

http://www.stoptech.com/tech_info/wp_warped_braked...

I've read the top article before.

Brake discs were brand spanking and steering wheel juddered as soon as I left the garage,can't have been uneven transfer.

The front o/s disc was returned to Audi for analysis.Returned with car two weeks later,replaced discs,no judder.

FYI the garage was a Audi RS tuner who remarked to me at the time "these aren't the first discs of this batch we've had to send back."

Go figure!

Edited by goldblum on Sunday 15th August 01:50

Edited by goldblum on Sunday 15th August 01:52

[flemke]

goldblum said:

flemke said:

goldblum said:

Had same symptoms on my Audi.Garage replaced front discs and no more judder.They were warped.

Unlikely that they were warped.
Fwiw:

technical source said:

...in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc.
In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

Much more detailed explanation here:

http://www.stoptech.com/tech_info/wp_warped_braked...

I've read that article before.

Brake discs were brand spanking and steering wheel juddered as soon as I left the garage,can't have been uneven transfer.

The front o/s disc was returned to Audi for analysis.Returned with car two weeks later,replaced discs,no judder.

FYO the garage was a Audi RS tuner who remarked to me at the time "these aren't the first discs of this batch we've had to send back."

Go figure.

"

I suppose it's possible that the discs were produced defectively. They're not going to get hot enough during the facing to distort the "disc" part. Maybe the stud holes were out? Is it possible that the bells were not faced in parallel with the friction surface?
Normally when people write about their discs being "warped", that is after hard use, and they imagine that the heat from heavy braking caused the iron to change shape, rather than the whole problem's being uneven deposits of the pad material.

[goldblum]

flemke said:

goldblum said:

flemke said:

goldblum said:

Had same symptoms on my Audi.Garage replaced front discs and no more judder.They were warped.

Unlikely that they were warped.
Fwiw:

technical source said:

...in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc.
In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

Much more detailed explanation here:

http://www.stoptech.com/tech_info/wp_warped_braked...

I've read that article before.

Brake discs were brand spanking and steering wheel juddered as soon as I left the garage,can't have been uneven transfer.

The front o/s disc was returned to Audi for analysis.Returned with car two weeks later,replaced discs,no judder.

FYO the garage was a Audi RS tuner who remarked to me at the time "these aren't the first discs of this batch we've had to send back."

Go figure.

"

I suppose it's possible that the discs were produced defectively. They're not going to get hot enough during the facing to distort the "disc" part. Maybe the stud holes were out? Is it possible that the bells were not faced in parallel with the friction surface?
Normally when people write about their discs being "warped", that is after hard use, and they imagine that the heat from heavy braking caused the iron to change shape, rather than the whole problem's being uneven deposits of the pad material.

Yes I think you're right.

On the balance of things they were probably sent out defective,as they had no "hard use" before I noticed judder.

[bull996]

BMW are renowned for the wheel wobble.

Certainly the E34 and E39 had these issues, and while the E34 is usually cured with new upper and lower control arms, the E39 is certainly not that easy. I spend £2k on my E39 and it never went away, so I sold it.

I hope the same issue is not with the E60-do they still have the same sort of set up?????

[CommanderJameson]

I have an E39 which has had two instances of vibration through the steering wheel.

The first instance would occur at approximately 75MPH, which was annoying as that's my lazy motorway cruising speed. 65 or 80 were fine. This turned out to be front wheel balance.

The second instance would occur under braking and was due to rear discs that had reached the end of their life. New discs resolved it.

The car is also sensitive to tyre pressure. You don't need to get very far from the correct 2 bar front/2.3 bar rear for it to start to feel wrong.

[ALawson]

I had the same problem with my ATR, after changing "warped disks" with new disks and pads the problem was still there (the disks needed changing anyway), checked the balance of the wheels, checked the wheels were round.

In the end it was the sliders that the pads sat in that were in need of any overhaul due to lots of brake dust casing the caliper to stay on.

[road_rager]

Sounds like you have a warped disc. This can happen if the wheel nuts were over tightened when the discs were changed. You also need to check you don't have a sticking brake caliper, after a run check the wheels for heat. Ultimately you'll probably have to get the discs skimmed to get them flat (after you've found the reason for the warp)

[sinizter]

Had similar on me Z4. One of the front brakes were seized. Otherwise, car seemed almost normal. But I could feel it through the pedals as well.

[vinnie83]

Thanks for the replies guys....

I can only feel it through the steering - not just feel it but the wheel actually wobbles in my hand, which feels quite dangerous.

It only happens on hard braking from speed, if I lightly brake it feels perfectly normal...

It was only very slightly evident when I first got the car but now is quite bad.

[goldblum]

Quite possibly defective when fitted then.

[wolf1]

Get the front suspension bushes, ball joints and track rod ends checked.

[frosted]

Sounds like your car had an encounter with a curb and was fixed on the cheap

[SarlechS]

wolf1 said:

Get the front suspension bushes, ball joints and track rod ends checked.

x2

[FasterFreddy]

flemke said:

goldblum said:

Had same symptoms on my Audi.Garage replaced front discs and no more judder.They were warped.

Unlikely that they were warped.
Fwiw:

technical source said:

...in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc.
In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

Much more detailed explanation here:

http://www.stoptech.com/tech_info/wp_warped_braked...

I totally agree with this. I'd say the term 'warped disc' is used these days to describe a number of different defects all with roughly the same symptom, but usually the cause is the pads remaining in contact with the disc after they've both got very hot causing this deposit on the disc surface.

Often happens with a car with new discs/pads driven hard for the first time (such as a track day) and left standing for a while after the run.

Prevention is better than cure as often the discs will either need to be skimmed or replaced and the pads renewed if this happens.

Bed in the pads/discs properly and give the braking system a chance to cool down before coming to a stop so excessive heat soak can't do any permanent damage.

If the OP's symptoms are all felt through the steering, I'd agree with the above posts that it's less likely to be 'warped discs' and more likely to be a suspension or steering component loose or worn.