[HighlandPete]

Originally Posted by Frenchstar-57

to my mind, the bolt are design to center (thanks to the conic head) and maintain the wheel against the hub on the horizontal plan. But they are not design to resist against shear stress (vertical forces).

it's the job of the grip contact zone between the wheel and hub.

BMW have used hub-centric mounts, hence the 0.15mm maximum clearance I referred to in a previous post. Keeps the radial mounting 'error' to a maximum of 0.075mm.

If the G30 has more clearance and relies on the clamping forces to resist radial movement, (not sure it should be like this), I can see how the friction disc is helping the accuracy of mounting and reducing vibrations.

Still requires care on mounting, clamping accurately and with a good clamping force before taking weight on the wheels.

[Frenchstar-57]

Hello,
Friction disc received, the thickness is about 0,1mm and the surfaces are covered with a grip substance like sanding paper.

[Haradrim]

Originally Posted by Frenchstar-57

Hello,
Friction disc received, the thickness is about 0,1mm and the surfaces are covered with a grip substance like sanding paper.

Hello Thank you for updates.

I think with this type of surface, movements of wheel preventing

Waiting to hear your results

Alper

[HighlandPete]

Originally Posted by Haradrim

Hello Thank you for updates.

I think with this type of surface, movements of wheel preventing

Waiting to hear your results

Alper

Also waiting to read the results. Any chance of measuring the dimensions and/or clearance between hub spigot and rim centre bore?

The G30 hub spigot is supposed to be 66.5mm and typical rim bores are recorded to be 66.6mm

[Frenchstar-57]

Originally Posted by HighlandPete

Also waiting to read the results. Any chance of measuring the dimensions and/or clearance between hub spigot and rim centre bore?

The G30 hub spigot is supposed to be 66.5mm and typical rim bores are recorded to be 66.6mm

I have already measured my winter wheels rim bores with which i have the vibration problem too, i confirm you that it's 66,6 mm.
for the hub spigot, i will mesure them in the same time as mounting friction discs.

[HighlandPete]

Originally Posted by Frenchstar-57

I have already measured my winter wheels rim bores with which i have the vibration problem too, i confirm you that it's 66,6 mm.
for the hub spigot, i will measure them in the same time as mounting friction discs.

Excellent, hope it goes well and does the job. BTW, are you adding tape to the spigot to get a more precise radial fit?

Thinking about this issue, I do wonder if BMW changing the hubs, lug bolt positions (as the technical image I posted above), is having a part to play in allowing more vibrations, if a precision mount is not maintained.

[Haradrim]

Originally Posted by Frenchstar-57

Hello,
Friction disc received, the thickness is about 0,1mm and the surfaces are covered with a grip substance like sanding paper.

Sorry i've forgot to ask;

the item no is: 34106884839 right?

[Frenchstar-57]

Originally Posted by Haradrim

Sorry i've forgot to ask;

the item no is: 34106884839 right?

Yes it is

[Frenchstar-57]

Hello,

I Received my disc and mounted it on the REAR AXLE and i did my usual test on the highway close to my house :

- the vibration decreased slightly, but it still vibrate as usual with an important part from the front axle (i can feel the vibrations on my foot from the gas pedal)

So i decided to operate one the front axle : put 2 layer of rubber tape on the front hub spigots and i cleaned the surface contact between the wheel and the hub, on the interior surface wheel, you can remark that there are factory regular scratch , so i took a sand paper and i did some scratch on the hub, to match the wheel 'factory' scratch. i tight the bolt when the wheel was just in contact with the ground, to avoid load constraint on the bolts during the operation.

And i did the same highway test in the same conditions :
- i can say that there is a great difference : almost smooth driving !

My conclusion is that vibration are coming from front as well from rear
The way to mount the wheel affect vibration level

[CnSky]

Interesting I will try the same and report back.

[Frenchstar-57]

Originally Posted by CnSky

Interesting I will try the same and report back.

Dont't forget to tight the bolt with 140NM torque, because usually, mechanics tight with 110-120 NM torque

[CnSky]

Is that BMW spec as I always use the standard spec on the torque wrench?

[Frenchstar-57]

Originally Posted by CnSky

Is that BMW spec as I always use the standard spec on the torque wrench?

140NM are now BMW standard spec

[Haradrim]

Originally Posted by Frenchstar-57

Hello,

I Received my disc and mounted it on the REAR AXLE and i did my usual test on the highway close to my house :

- the vibration decreased slightly, but it still vibrate as usual with an important part from the front axle (i can feel the vibrations on my foot from the gas pedal)

So i decided to operate one the front axle : put 2 layer of rubber tape on the front hub spigots and i cleaned the surface contact between the wheel and the hub, on the interior surface wheel, you can remark that there are factory regular scratch , so i took a sand paper and i did some scratch on the hub, to match the wheel 'factory' scratch. i tight the bolt when the wheel was just in contact with the ground, to avoid load constraint on the bolts during the operation.

And i did the same highway test in the same conditions :
- i can say that there is a great difference : almost smooth driving !

My conclusion is that vibration are coming from front as well from rear
The way to mount the wheel affect vibration level

First of all thank you for your detailed informative feedbacks.

I am very happy to hear that your issues are gone. With the front discs there will be no problem i think.

I also ordered 34106884839 via warranty for rears. The fronts are ordered according to my feed backs. My 4 wheels are ready rubber band covered. So know, still perfect results

I wanted to ask you these discs put on the part which i shown below?


Thank you

[Frenchstar-57]

Originally Posted by Haradrim

First of all thank you for your detailed informative feedbacks.

I am very happy to hear that your issues are gone. With the front discs there will be no problem i think.

I also ordered 34106884839 via warranty for rears. The fronts are ordered according to my feed backs. My 4 wheels are ready rubber band covered. So know, still perfect results

I wanted to ask you these discs put on the part which i shown below?


Thank you

To resume, i ordered only 2 discs, and before installing it i do some tests -> my seat was like a vibrator
- after mounting 2 disc on the rear, slightly decrease, but it was not conclusive, more vibration to the front and still seat vibration
- after cleaning the hub and the wheel in the front axle, and add rubber on the hub spigot, significant result

I confirm that disc are fitting perfect on the hub.

Before put the disk, clean the hub and wheel, no grease or other lubricant ! (some mechanics are used to add grease of the surface contact between hub and wheel)
then do some scratch on the hub with 120 sand paper and add the disc and the wheel
Tight the bolt a maximum by the hand using a cross, when the wheel is suspended, then lower the crick just to touch slightly the ground and tight to 140NM torque

I think if i add disc to the front, the results could be better, but for the moment it's okay (i tested this morning again).

[HighlandPete]

Originally Posted by Frenchstar-57

Before put the disk, clean the hub and wheel, no grease or other lubricant ! (some mechanics are used to add grease of the surface contact between hub and wheel)
then do some scratch on the hub with 120 sand paper and add the disc and the wheel
Tight the bolt a maximum by the hand using a cross, when the wheel is suspended, then lower the crick just to touch slightly the ground and tight to 140NM torque

I think if i add disc to the front, the results could be better, but for the moment it's okay (i tested this morning again).

Does appear we are getting the same issue and requiring a similar solution (except for the friction disc), as we have seen since the E39. Quite a few F10/11 owners, with basically the same suspension as the G30, also have the same mounting issues.

One of my posts from a similar topic for the F10.

Reminds me of the E39 'shimmy' issues, where some examples could be very sensitive to any wheel and/or hub run-out, imbalance or slight suspension wear. Wheel mounting accuracy was a critical part of reducing and eliminating shimmy. Doesn't take much of a mounting error to amplify the problem at the rolling frequency bands where we get shake.

[Frenchstar-57]

Originally Posted by HighlandPete

Does appear we are getting the same issue and requiring a similar solution (except for the friction disc), as we have seen since the E39. Quite a few F10/11 owners, with basically the same suspension as the G30, also have the same mounting issues.

One of my posts from a similar topic for the F10.

I think The rubber around the hub helps to reduce the tolerance and improve the centering of the wheel during the mount.

The bolt tighting way, order and torque are important too

About The disc, they are very thin, 0,1mm, covered with a scratchy surface, it don't help to center the wheel, it only add friction between the two surfaces. i don't know if it is more scratchy than to do it manually on the hub with sanding paper..

[HighlandPete]

Originally Posted by Frenchstar-57

I think The rubber around the hub helps to reduce the tolerance and improve the centering of the wheel during the mount.

The bolt tighting way, order and torque are important too

About The disc, they are very thin, 0,1mm, covered with a scratchy surface, it don't help to center the wheel, it only add friction between the two surfaces. i don't know if it is more scratchy than to do it manually on the hub with sanding paper..

I agree, it does appear every little helps. The friction disc may simply help hold the wheel in the correct position while tightening. Possibly less critical if the wheels are torqued to a high enough value, before the wheel carries weight. If hand tight and dropped to the ground, before being torqued up, easy to picture an eccentric mount, with weight absorbing the 'clearance' to one side of the mounting spigot.

I also think the need for mounting precision is why some have changed wheel sets and there is little difference, while others have witnessed improvement. But it takes all four wheels to be mounted well, to be rid of the issues, if wheel induced.

BMW have always been sensitive to getting the wheel assembly right, (hub, brake disc, rim, tire balance), to eliminate wheel vibrations. Particularly so, as we increase rim diameters.

[Frenchstar-57]

Originally Posted by HighlandPete

I agree, it does appear every little helps. The friction disc may simply help hold the wheel in the correct position while tightening. Possibly less critical if the wheels are torqued to a high enough value, before the wheel carries weight. If hand tight and dropped to the ground, before being torqued up, easy to picture an eccentric mount, with weight absorbing the 'clearance' to one side of the mounting spigot.

I also think the need for mounting precision is why some have changed wheel sets and there is little difference, while others have witnessed improvement. But it takes all four wheels to be mounted well, to be rid of the issues, if wheel induced.

BMW have always been sensitive to getting the wheel assembly right, (hub, brake disc, rim, tire balance), to eliminate wheel vibrations. Particularly so, as we increase rim diameters.

Totally agree with you, on top of that, the hub spigot is so short, that the wheel hardly hold on the hub without bolt during mounting, it add error centering possibility.

[Haradrim]

Originally Posted by Frenchstar-57

To resume, i ordered only 2 discs, and before installing it i do some tests -> my seat was like a vibrator
- after mounting 2 disc on the rear, slightly decrease, but it was not conclusive, more vibration to the front and still seat vibration
- after cleaning the hub and the wheel in the front axle, and add rubber on the hub spigot, significant result

I confirm that disc are fitting perfect on the hub.

Before put the disk, clean the hub and wheel, no grease or other lubricant ! (some mechanics are used to add grease of the surface contact between hub and wheel)
then do some scratch on the hub with 120 sand paper and add the disc and the wheel
Tight the bolt a maximum by the hand using a cross, when the wheel is suspended, then lower the crick just to touch slightly the ground and tight to 140NM torque

I think if i add disc to the front, the results could be better, but for the moment it's okay (i tested this morning again).

Thank you again for detailed informations.

So in case of my car is under warranty, the discs will mounting at dealer

I will give instruction as you applied. I also ordered 2, because dealer still thinks it wont help if its success they will also order for front.

I wanted to ask you the disc put on this surface?




Keep you updated

Thank you

[Frenchstar-57]

Originally Posted by Haradrim

Thank you again for detailed informations.

So in case of my car is under warranty, the discs will mounting at dealer

I will give instruction as you applied. I also ordered 2, because dealer still thinks it wont help if its success they will also order for front.

I wanted to ask you the disc put on this surface?




Keep you updated

Thank you

Yes this is on this surface.

[Haradrim]

Originally Posted by Frenchstar-57

Yes this is on this surface.

Thank you, so i think that these disks increase the friction and not permitting any movement on hub or disc surface.

With my investigations, some dealers uses this friction disks for click sound coming from wheelhubs or brakes.

So can we think there was a factory based problem on hubs of g30?