[jrsniper12453]

As the title says, just noticed steering wheel vibration on moderate and above braking. I can't remember noticing it before but I could have missed it. I don't track it or anything that would lead to me being particularly punishing on the brakes. Anyone have experience with our rotors warping? Or is it the wheels (no vibration unless braking) or maybe I just need to clean the rotors?

Any input would be great.

[Letsrunem8]

Originally Posted by jrsniper12453

As the title says, just noticed steering wheel vibration on moderate and above braking. I can't remember noticing it before but I could have missed it. I don't track it or anything that would lead to me being particularly punishing on the brakes. Anyone have experience with our rotors warping? Or is it the wheels (no vibration unless braking) or maybe I just need to clean the rotors?

Any input would be great.

Sounds like your rotors are warped/created hot spots or only glazed. Happens all the time when the friction between your brakes and rotors heat up excessively. Go to a local certified BMW shop and have them inspected. If possible you can turn/resurface them (although BMW rotors are meant to be replaced). If not you might need some new ones!

[bsamoul]

Sounds like your rotors need to be replaced. BMW rotors aren't really meant to be refinished.

[Orion4]

Agree, that is the classic indicator for warped front rotors. If you don't feel it in the steering wheel, but rather in your seat/chassis - look to the rear rotors- but that is not usually the case.

[twerle]

I have the same issue on mine and it is annoying! I need to replace the rotors/pads/sensor and all new thru BMW will cost you $1,200.00 with service, all 4.

I hope you only need to replace the front one, on my case I need to replace all 4 of them :-(

[m@rco]

Originally Posted by Letsrunem8

Sounds like your rotors are warped/created hot spots or only glazed. Happens all the time when the friction between your brakes and rotors heat up excessively. Go to a local certified BMW shop and have them inspected. If possible you can turn/resurface them (although BMW rotors are meant to be replaced). If not you might need some new ones!

This issue is not uncommon for cars with a lot of stop and go use and more prone to automatic transmission cars than MT6s. Independent of brand etc.. When you leave your foot on the brake after (hard) braking, the disk doesn't cool down equally over the entire disk. There where the brake pads touch the disk, a greater heat dissipation takes place creating small tensions inside the disk. As a result, over time, the disk starts to deform a little. This causes vibration when braking.

Best way to avoid this is to take your foot off the brake after braking hard (until full stop). Put the gear in neutral.

Don't put the gear in neutral if there is no real reason. That would only wear the parts inside the gearbox and this is even more expensive to repair.

[GoRomeo]

This hapens to me too. My passenger seat vibrates too a bit not steerimg wheel. I know i need new brakes and rotors in the front. Hopefully this will take of this issue. (I changed new rear pads last year but not the rotors).

[sunny]

it may only need new pad my car did the samething.
you might as well replace both pad and rotors.

[335BBS]

[QUOTE=m@rco;11015356]This issue is not uncommon for cars with a lot of stop and go use and more prone to automatic transmission cars than MT6s. Independent of brand etc.. When you leave your foot on the brake after (hard) braking, the disk doesn't cool down equally over the entire disk. There where the brake pads touch the disk, a greater heat dissipation takes place creating small tensions inside the disk. As a result, over time, the disk starts to deform a little. This causes vibration when braking.

Best way to avoid this is to take your foot off the brake after braking hard (until full stop). Put the gear in neutral.

Don't put the gear in neutral if there is no real reason. That would only wear the parts inside the gearbox and this is even more expensive to repair.[/QUOTE]


If you live by that theory then you had better not use the car at all as any use will cause wear and tear. Sorry but this is a ridiculous statement.

[GoRomeo]

Originally Posted by sunny

it may only need new pad my car did the samething.
you might as well replace both pad and rotors.

Yes I will change pads and rotors in front. I will let you guys know if my seat vibration goes away, if not I will replace front tires.

[335BBS]

Originally Posted by GoRomeo

Yes I will change pads and rotors in front. I will let you guys know if my seat vibration goes away, if not I will replace front tires.

If it only happens while braking then it has nothing to do with tires.

[GoRomeo]

Originally Posted by Leaker

If it only happens while braking then it has nothing to do with tires.

Thank you,

It does NOT happen while breaking. Only when I am on the freeway going about 85 mph. then I see my passenger seat vibrating...any suggestions what can it be? Thanks again guys!

[m@rco]

Originally Posted by GoRomeo

Thank you,

It does NOT happen while breaking. Only when I am on the freeway going about 85 mph. then I see my passenger seat vibrating...any suggestions what can it be? Thanks again guys!

You are suffering from an unbalance in your wheels. I believe this is the unbalance of the "second order" (second eigen frequency). "First order" (first eigen frequency) happens around 50 MPH...

Typically, the first degree unbalance is overcome by "static balancing" of your wheels. Static balancing simply means the insurance of mass distribution about the axis of rotation of the rotating mechanical part in the radial directions, without consideration of that distribution in the axial (longitudinal) direction.

The second degree unbalance is a result of an incorrect alignment of the counter balancing weights, and requires dynamic balancing. The latter differs from static balancing in that the mass distribution of the part is detected in all directions, and not only about the central axis; and so, not only the magnitude of the unbalanced mass and its distance from the axis of rotation are to be determined, but also its position in the axial (longitudinal) direction of the rotational part.

Am I clear?!? Sorry for the technical terms but I don't know how else to explain it...

Less likely, you may suffer from any of the following issues:
- unequal tire pressure between left and right
- serious tire defect (cut), serious unequal wear
- incorrect alignment of your wheels
- faulty steering dampener
- you might have lost a little weight (as a result of using the high pressure hose when cleaning your wheels...)

Anyway, go back to the company that mounted your tires and ask for dynamic balancing.

[GoRomeo]

Originally Posted by m@rco

You are suffering from an unbalance in your wheels. I believe this is the unbalance of the "second order" (second eigen frequency). "First order" (first eigen frequency) happens around 50 MPH...

Typically, the first degree unbalance is overcome by "static balancing" of your wheels. Static balancing simply means the insurance of mass distribution about the axis of rotation of the rotating mechanical part in the radial directions, without consideration of that distribution in the axial (longitudinal) direction.

The second degree unbalance is a result of an incorrect alignment of the counter balancing weights, and requires dynamic balancing. The latter differs from static balancing in that the mass distribution of the part is detected in all directions, and not only about the central axis; and so, not only the magnitude of the unbalanced mass and its distance from the axis of rotation are to be determined, but also its position in the axial (longitudinal) direction of the rotational part.

Am I clear?!? Sorry for the technical terms but I don't know how else to explain it...

Less likely, you may suffer from any of the following issues:
- unequal tire pressure between left and right
- serious tire defect (cut), serious unequal wear
- incorrect alignment of your wheels
- faulty steering dampener
- you might have lost a little weight (as a result of using the high pressure hose when cleaning your wheels...)

Anyway, go back to the company that mounted your tires and ask for dynamic balancing.

Hey thanks for your reply but what do you mean by "unbalance of the "second order" (second eigen frequency). "First order" (first eigen frequency) happens around 50 MPH... "???

I am not having any of the issues you mentioned. I have the 182 rims I got 2 years ago and already came with the tires. I bought all 4 already with tires. I just remove the 162's and replace them with 182 did not balance. So thats probably why..

What I will do is change the pads and rotors as I already bought the parts and then proceed with the alignment like you mentioned.

[Bcube]

Originally Posted by jrsniper12453

As the title says, just noticed steering wheel vibration on moderate and above braking. I can't remember noticing it before but I could have missed it. I don't track it or anything that would lead to me being particularly punishing on the brakes. Anyone have experience with our rotors warping? Or is it the wheels (no vibration unless braking) or maybe I just need to clean the rotors?

Any input would be great.

How many miles on the car? When the front suspension tension strut bushings begin to degrade, you'll get this effect upon moderate and heavy braking.

[jrsniper12453]

Originally Posted by Bcube

How many miles on the car? When the front suspension tension strut bushings begin to degrade, you'll get this effect upon moderate and heavy braking.

42k. Also I couldn't get it to show up again today when I tried to brake pretty hard coming off a highway. So it only happened so far when slowing down from higher speeds and after doing a 10+ pulls to log car