[CALWATERBOY]

Originally Posted by Stream

It didnd't work for me. Twice! Harder you brake - harder steering wheel shakes. Maybe it's pad deposits, but you can't remove them with rebedding or agressive braking.

I think OP has the same problem.

Then most likely a bushing issue. And, yep, check your transmission fluid level.

Originally Posted by Stream

It didnd't work for me. Twice! Harder you brake - harder steering wheel shakes. Maybe it's pad deposits, but you can't remove them with rebedding or agressive braking.

I think OP has the same problem.

Of course you won't be able to remove pad deposits when trying to aggressively brake with THE SAME PADS THAT CAUSED THE DEPOSITS IN THE FIRST PLACE!!

You need to use a more aggressive pad than the ones that are already on there...

[feuer]

Originally Posted by CALWATERBOY

Experience - can't say why it happens, as a technical explanation. But feels just like an overheated rotor! Did not do when cold.

AT or MT, or both? What if you brake while in Neutral? Will that eliminate the possibilities of transmission contribution towards brake vibrations?

Please don't get me wrong. I'm asking because I have a customer's e92 335i with engine running hot and transmission harsh shifting that I have been working on and driving around for almost a week now.

We replaced all of the suspension front and rear and the brakes because they vibrated. It was OK for a little bit then returned.

I installed brass bushings on the calipers. Next on the list is SFB inserts. Also I will send out the rotors to be turned down and the wheels to be re-balanced.

If the vibrations return I will look into the AT. I hope I will not have to.

[Stream]

Originally Posted by feuer

AT or MT, or both? What if you brake while in Neutral? Will that eliminate the possibilities of transmission contribution towards brake vibrations?

Please don't get me wrong. I'm asking because I have a customer's e92 335i with engine running hot and transmission harsh shifting that I have been working on and driving around for almost a week now.

We replaced all of the suspension front and rear and the brakes because they vibrated. It was OK for a little bit then returned.

I installed brass bushings on the calipers. Next on the list is SFB inserts. Also I will send out the rotors to be turned down and the wheels to be re-balanced.

If the vibrations return I will look into the AT. I hope I will not have to.

Hmmm.... Wheel hub runout is out of spec or it's imposible?

[feuer]

Originally Posted by Stream

Hmmm.... Wheel hub runout is out of spec or it's imposible?

Yes, I will look into that as well. It was handled by a different mechanic previously.
I need to do a lot of work on this car, is a mess.

[Meeni]

Do not dismiss a damaged/ovoid wheel too quickly either.

[Fundguy1]

Rotors do warp. When I had a Nissan armada and a g35 they were both recalled for warping rotors. Both needed 3 sets before they got it right. It was not proper pad seating issue etc.

[CALWATERBOY]

Originally Posted by feuer

AT or MT, or both? What if you brake while in Neutral? Will that eliminate the possibilities of transmission contribution towards brake vibrations?

Please don't get me wrong. I'm asking because I have a customer's e92 335i with engine running hot and transmission harsh shifting that I have been working on and driving around for almost a week now.

We replaced all of the suspension front and rear and the brakes because they vibrated. It was OK for a little bit then returned.

I installed brass bushings on the calipers. Next on the list is SFB inserts. Also I will send out the rotors to be turned down and the wheels to be re-balanced.

If the vibrations return I will look into the AT. I hope I will not have to.

Yep, had vibration in neutral. Was time to change fluid - surprised to find vibe cured!

Assume you've eliminated tires & rims as trouble. Then, may be time to do this or 335i equiv. How's mechatronic seal look?

[Fundguy1]

Mine are brand new and feel warped. I can only assume it's pads or warped. I'm going to try different pads. I have a manual so it isn't Trans.

[feuer]

Originally Posted by CALWATERBOY

Yep, had vibration in neutral. Was time to change fluid - surprised to find vibe cured!

Assume you've eliminated tires & rims as trouble. Then, may be time to do this or 335i equiv. How's mechatronic seal look?

The AT was serviced recently. It was not leaking. New seal, new filter and fresh RedLine. Although the shifts from 2nd to 3rd are better you can still feel slight jolt. Same when you are coming to a full stop. I assume shift from 2nd into 1st. The car would surge a little forward. Not all the time though.
I have replaced individual body valves and whole units in the past myself but since I'm NOT enough inclined to rebuild a AT next I will try is reprogramming and if that doesn't help look into just swapping it for another unit.

>this is for another thread<

Originally Posted by Fundguy1

Mine are brand new and feel warped. I can only assume it's pads or warped. I'm going to try different pads. I have a manual so it isn't Trans.

Yes, that is why asked CALWATERBOY whether was vibrating in neutral as well. You have MT and experiencing problems.

I know for a fact is not a suspension related because on this particular e92 everything is brand new.

I have 2 items on my list:
-wheels > send out to be re-balanced and straighten if needed (brand new Conti DWS)
-rotors > turning down to clean up all possible pad deposit.

Perhaps, slotted rotors with aggressive pads would stop this issue of re-occurring in the future.

[Hydraulic]

Sorry to necro a dead thread but its top of Google for this issue on e90s and the correct answer was never posted. In short every post here is wrong. Rotors do not warp, they wear unevenly. This occurs when the rotors are installed with static lateral runout. Even if the rotor is true, or turned off the car, if the wheel hub axis is not perfect with the caliper bolt bores axis, runout will exist and must be corrected. Dirt rust or paint on hub can cause this or just the way the wheel bearing sits can. When pedal pressure is released, the high spot on rotor rubs the pad every turn of wheel, and 180 degrees other side of rotor does the same on other pad. This wears two opposing spots in rotor turning it potato chip shaped. You must measure runout with a magnetic base dial gauge attached to strut or knuckle(difficult or impossible with drilled and slotted) during rotor install. If out of spec(> .002") you can try flipping rotor 180 degrees, can try shims they make for this purpose, or best way or way to resolve after its occurred, is to get an on car brake lathe used on the rotors which is not expensive. An on car lathe will use the caliper bolts as an axis, and thus will eliminate runout that an off car lathe will not and resolve this problem that has cost the op and many others(including me until I became an expert on brakes to resolve it myself...) hundreds and hundreds of dollars.

Go away noob...the runout is more likely caused by uneven pad deposits; not wheel hub axis not being perfect...you'll never find a scenario where those, or any other tolerances within those suggested components, are perfect:
https://alconkits.com/technical-info...ed-brake-discs

Why you chose to bump such an old thread with a nonsense argument was a crappy way to introduce yourself.

[Hydraulic]

Originally Posted by FCobra94

Go away noob...the runout is more likely caused by uneven pad deposits; not wheel hub axis not being perfect...you'll never find a scenario where those, or any other tolerances within those suggested components, are perfect:
https://alconkits.com/technical-info...ed-brake-discs

Why you chose to bump such an old thread with a nonsense argument was a crappy way to introduce yourself.

After spending hundreds(and far more if I paid a shop) on new rotors, new pad types, trying different bedding procedures, having them turned off car, and being frustrated for a long time, I decided to leave the conclusion of how to fix this issue here, to hopefully save someone else in the same spot the headache i experienced from bad information such as you have provided. Pad deposits I have never seen, but I sure as shit tried to bed the pads correctly multiple times, and after a rebed procedure never noticed a slight difference, if you do notice a difference look at deposits sure, otherwise get a 40$ on car lathe done and fix this issue correctly, have not had an issue in 18k miles since when the "warping" returned every 2-3k prior, Ebc rotors or cheap rotors alike. Your hostile response is a sh*ty way to respond to useful information.

Here's a counter source to your link, written by a mechanical engineer that designs brake systems:
http://www.hendonpub.com/resources/a...etails?id=1787

Yes, thank you for proving my point...did you just so happen to miss this quote within the article you posted:

As this happens, the semi-metallic pad used with police cars will grind away the high spots on either side. On the other hand, the ceramic pad used with retail cars will transfer material to the high spots. In just a few thousand miles, the rotor will have a significant thickness variation, either from worn away rotor or material transfer from the pad.

Those "transfer materials" are the pad deposits I originally mentioned.

Of course it's important to tighten down a wheel correctly...that's common sense. Anything beyond your control though will result in pad transfer; and again, it's not due to "cheap" rotors, but the specific pad material instead.

This is why most have the best experience with avoiding "warping" when running aggressive pads on the street...your article says just that.

Also, the fact that you were able to find an on-car lathe that was calibrated correctly, had a sharp enough tool bit, etc. is pretty remarkable. Most people aren't that lucky. Most "professionals" can't even properly balance a tire, much less, turn a rotor down to within 0.002"

[Hydraulic]

Originally Posted by FCobra94

Yes, thank you for proving my point...did you just so happen to miss this quote within the article you posted:

Those "transfer materials" are the pad deposits I originally mentioned.

Of course it's important to tighten down a wheel correctly...that's common sense. Anything beyond your control though will result in pad transfer; and again, it's not due to "cheap" rotors, but the specific pad material instead.

This is why most have the best experience with avoiding "warping" when running aggressive pads on the street...your article says just that.

Also, the fact that you were able to find an on-car lathe that was calibrated correctly, had a sharp enough tool bit, etc. is pretty remarkable. Most people aren't that lucky. Most "professionals" can't even properly balance a tire, much less, turn a rotor down to within 0.002"

Do you have a solution to fix the issues I experienced other than what finally worked for me? Or just shooting down what I stand by is valuable information for the sake of it? I replaced rotors multiple times. Replaced with high quality EBC rotors even. Had them turned off the car. Had a shop tell me to replace my calipers, which I didn't as they were replaced about 60k ago. Had a shop tell me to put all new bushings in the front which I was skeptical of none were blown or had noticable play. Had a mechanic tell me mb it was wheel bearing. And after all of this, I finally resolved it, with an on car lathe being done for 40$. This resolution that worked for me was never mentioned here and this is the first search result on this issue thus I posted it instead of unnecessarily making a new thread. No matter how I tried to bed new pads it did not make a difference in my case, nor did trying to rebed after these presumed invisible deposits were there(which never made a difference either). I am telling what worked for me and what I wish I did for 40$ from the start, so that it may possibly save someone else from this headache, I am unsure why that idea seems so offensive to you.

Originally Posted by Hydraulic

I am telling what worked for me and what I wish I did for 40$ from the start, so that it may possibly save someone else from this headache, I am unsure why that idea seems so offensive to you.

Because

Originally Posted by FCobra94

the fact that you were able to find an on-car lathe that was calibrated correctly, had a sharp enough tool bit, etc. is pretty remarkable.

I'm glad this worked for you, but very unlikely for most to repeat this solution reliably for the obvious response already given.

[Chappers 71]

Over the seven years I've owned my 35i I've had steering judder under a braking a few times.

Not long after buying my 35i I fitted Pagid discs all round with Red Stuff ceramic pads.

First time it happened I had the discs skimmed whilst on the car to eliminate run out. This cured it for a few thousand miles only for it to return, so I fitted new discs, Brembos this time & the juddering was cured for 18,000 miles.
When it returned it turned out to be the right hand side (drivers side for those of us that drive on the correct side of the road) lower control arm, it was only diagnosed by an experienced tech with the car on a shaker ramp. I replaced both lower control arms and the juddering was again cured..for 8 months or so until it returned a couple of months ago.
I have now replaced both front discs with Ate discs & have swapped out the Red Stuff pads to none ceramic Brembo pads. The shuddering had now gone & the brakes feel much smoother & work better at low speeds although they are not as good when braking hard from high speed & they give off more brake dust.
When I took of the old discs they were quite badly scored with & I could feel & see circular ridges especially on the inner face of the discs.

Each time I've changed the discs I've cleaned the hub & all the other parts & carefully reassembled and I've fitted new slider pins.
Hopefully this time the brake judder won't return as I suspect that the ceramic pads may have been the cause of my problem....time will tell.

I've attached a link to the brake reskimming machine used on my 35i for those of you that may be interested

https://www.google.com/url?sa=t&sour...k5sQUUArd_2mmi