[Haradrim]

Hello All

As you all know the very common problem of g30 is vibrations since we bought it or changed tyres.

Many solution tried
- Tyres changed
- Best centering tried
- Road force balances, harmonic balances etc.

All the things we have done always decreased the vibration but didnt clear them all.

So we have only one forum friend which is at germany informed us. his car gone to bmw rnd factory and they change rear subframe bushes with 7 series and problem is gone.


So me and my friend tried this today. Because this solution done by bmw and they know what they do

Ordered 2 pcs of g11 7 series rear subframe bushings. its completely suitable for g30 rear subframe bushes.

So let me first show you the g11 subframe bushing and g30

g30 normally has rubber subframe bushing



So let me show below the g11



so the existing bushing is rubber and very weak thing. you can feel it when you touch.

But g11 is heavy and strong one. its hydro bushing. almost 1 1.5kg weight.

So we the holes and bushing diameter is 90mm. thats why you need hydraulic press to put new bushings easily.

We demounted the rear axle carrier. and mounted on axle.

here is the final
[IMG][/IMG]

So after all this done rear carrier ready to mount back on car and test drive

[IMG][/IMG]

For your informations, this car doesnt have any spacer, friction disk or etc. Only balance settings done and mounts changed.


We have done the highway test today about 50-60 km range.

And voilà.. No vibration at all..


Main problem of bmw g30 is, these rubber bushes cant absorb to the vibration from force feedbacks from road. And only connection of car body and wheels are these rubbers. And these are not enough.

All the things we have done previously have same main purpose. Lowering feedbacks coming from the tyre

Spacers
low road force tyres
rubbers on spigots
centering etc.

But still some force coming from road but these rubbers 0 effect on absorbing


I hope all these information will help yours and solve the issues.

Best regards.

[lnxguy]

Great info, that's a big job.

[New5Series]

Originally Posted by Haradrim

Hello All

As you all know the very common problem of g30 is vibrations since we bought it or changed tyres.

Many solution tried
- Tyres changed
- Best centering tried
- Road force balances, harmonic balances etc.

All the things we have done always decreased the vibration but didnt clear them all.

So we have only one forum friend which is at germany informed us. his car gone to bmw rnd factory and they change rear subframe bushes with 7 series and problem is gone.


So me and my friend tried this today. Because this solution done by bmw and they know what they do

Ordered 2 pcs of g11 7 series rear subframe bushings. its completely suitable for g30 rear subframe bushes.

So let me first show you the g11 subframe bushing and g30

g30 normally has rubber subframe bushing



So let me show below the g11



so the existing bushing is rubber and very weak thing. you can feel it when you touch.

But g11 is heavy and strong one. its hydro bushing. almost 1 1.5kg weight.

So we the holes and bushing diameter is 90mm. thats why you need hydraulic press to put new bushings easily.

We demounted the rear axle carrier. and mounted on axle.

here is the final
[IMG][/IMG]

So after all this done rear carrier ready to mount back on car and test drive

[IMG][/IMG]

For your informations, this car doesnt have any spacer, friction disk or etc. Only balance settings done and mounts changed.


We have done the highway test today about 50-60 km range.

And voilà.. No vibration at all..


Main problem of bmw g30 is, these rubber bushes cant absorb to the vibration from force feedbacks from road. And only connection of car body and wheels are these rubbers. And these are not enough.

All the things we have done previously have same main purpose. Lowering feedbacks coming from the tyre

Spacers
low road force tyres
rubbers on spigots
centering etc.

But still some force coming from road but these rubbers 0 effect on absorbing


I hope all these information will help yours and solve the issues.

Best regards.

Very interesting, the vibrations on these vehicles are a huge annoyance and I’m glad you were able to find a true solution. Do you happen to have the parts numbers for the G11 bushings you used?

Also, this seems like a complicated and expensive fix, if you don’t mind me asking, how much did this end up costing you, and are you satisfied that this truly eliminated the vibrations?
Cheers

[Haradrim]

Originally Posted by New5Series

Very interesting, the vibrations on these vehicles are a huge annoyance and I’m glad you were able to find a true solution. Do you happen to have the parts numbers for the G11 bushings you used?

Also, this seems like a complicated and expensive fix, if you don’t mind me asking, how much did this end up costing you, and are you satisfied that this truly eliminated the vibrations?
Cheers

I can send you the part codes soon.

We spent 275€ for 2 pieces mounts
320€ for mechanic.
Total is 600€

[CnSky]

Well done sir!

[lnxguy]

Part #s should be 33316882793 and 33316882794.

Pulled from Realoem for a standard G11. Please correct me if I'm wrong.

[Kikac]

Very good job! I decided to do the same on my G31.

33316882793 is the front and 33316882794 is the back side. That would mean you need 4 pcs (left + right x 2)



I'll wait for Haradrim's reply to be sure since he mentioned he only replaced 2 pcs.

Thanks.

[sepurman]

Originally Posted by Kikac

Very good job! I decided to do the same on my G31.

33316882793 is the front and 33316882794 is the back side. That would mean you need 4 pcs (left + right x 2)

Attachment 3648282

I'll wait for Haradrim's reply to be sure since he mentioned he only replaced 2 pcs.

Thanks.

hello friend. I am the one who endured this torture and changed this piece. part number 33316882794.
It will be enough to buy 2 pieces and replace the rear bushings.
You cannot change the front bushings anyway, the dimensions are incompatible.
If you have any other questions, you can ask.

[Kikac]

Originally Posted by sepurman

hello friend. I am the one who endured this torture and changed this piece. part number 33316882794.
It will be enough to buy 2 pieces and replace the rear bushings.
You cannot change the front bushings anyway, the dimensions are incompatible.
If you have any other questions, you can ask.

Really appreciated. Did it eliminate all vibrations for you too?
I will order 2 pieces and let my local mechanic install it. Do i have to do a car allignment after?
Thanks a lot mate.

[sepurman]

Originally Posted by Kikac

Really appreciated. Did it eliminate all vibrations for you too?
I will order 2 pieces and let my local mechanic install it. Do i have to do a car allignment after?
Thanks a lot mate.

80% of the vibrations are caused by rubber bushings. It will be fixed when you replace them with hydro bushings. For the remaining 20%, you will have spacers made that are compatible with the rims and hubs and the problem will be completely solved.
In other words, 80% of the vibration comes from the bushings and 20% from the rim and hub space.
There is no need for alignment when installing the rear axle because there are protrusions in the section where the front parts of the axle are installed in the G30 5 series, you will see it on the page I shared.

[New5Series]

Originally Posted by sepurman

80% of the vibrations are caused by rubber bushings. It will be fixed when you replace them with hydro bushings. For the remaining 20%, you will have spacers made that are compatible with the rims and hubs and the problem will be completely solved.
In other words, 80% of the vibration comes from the bushings and 20% from the rim and hub space.
There is no need for alignment when installing the rear axle because there are protrusions in the section where the front parts of the axle are installed in the G30 5 series, you will see it on the page I shared.

sepurman Have you been experiencing any more vibrations since you had the bushings replaced? It has been a few months and I’m hoping this solution is the one that truly solves the vibration problem.

Cheers

[Krisztian93]

Hi Im also suffering with the vibration also tried everything different brand tyres, Roadforce , Spacers , Everything!!!
Wonder if this really sorted let us know pls

[Kikac]

Originally Posted by sepurman

80% of the vibrations are caused by rubber bushings. It will be fixed when you replace them with hydro bushings. For the remaining 20%, you will have spacers made that are compatible with the rims and hubs and the problem will be completely solved.
In other words, 80% of the vibration comes from the bushings and 20% from the rim and hub space.
There is no need for alignment when installing the rear axle because there are protrusions in the section where the front parts of the axle are installed in the G30 5 series, you will see it on the page I shared.

I have approached 4 garages for this job but none of them want to do this because according to them the rubbers are not officially allowed to be pressed/changed for others. Very strange but they all tell the same thing..

[Thomas911]

Hello @Sepurman
I've been following your modification of the rear axle mount silentbloc on a BMW G30 using BMW 7 Series parts.

I have a BMW 540I G31 and I'm experiencing vibration/rumble issues between 90 and 120 km/h.

I'm having the rear axle mounts modified by an independent garage.

They're having trouble inserting the 7 Series silentblocs. (33316882794)
Can you tell me how you did it?

My garage broke the hydraulic silentbloc while trying to insert it with a hydraulic press.

Thank you in advance for your help.
Thomas

[Kikac]

Originally Posted by Thomas911

Hello @Sepurman
I've been following your modification of the rear axle mount silentbloc on a BMW G30 using BMW 7 Series parts.

I have a BMW 540I G31 and I'm experiencing vibration/rumble issues between 90 and 120 km/h.

I'm having the rear axle mounts modified by an independent garage.

They're having trouble inserting the 7 Series silentblocs. (33316882794)
Can you tell me how you did it?

My garage broke the hydraulic silentbloc while trying to insert it with a hydraulic press.

Thank you in advance for your help.
Thomas

I also wanted to do this modification, maybe what you are describing is the reason none of the 4 garages i approached were willing to replace these rubbers.
Can you please keep us updated on this Where are you from?

[Thomas911]

Originally Posted by Kikac

I also wanted to do this modification, maybe what you are describing is the reason none of the 4 garages i approached were willing to replace these rubbers.
Can you please keep us updated on this Where are you from?

I'll will keep you inform as soon as it will be done.
I would like to contact Seprman or Haradrim, to understand how they procced to insert the 7 serie part

[Thomas911]

I am not allowed yet to use private message.
Does someone can please help me to contact "Seprman" or "Haradrim" to get some advice to insert 7 serie part? (As we broke the first one)
Thank you a lot for support.
Thomas
(you can provide my personal email address: thomaspineau@hotmail.com"

[Kikac]

Originally Posted by Thomas911

I'll will keep you inform as soon as it will be done.
I would like to contact Seprman or Haradrim, to understand how they procced to insert the 7 serie part

Thank you

I think the only way is with hydraulic press and the right size bushes (90mm)
Have you heated the rear axle before pressing the new rubbers?

[Thomas911]

Originally Posted by Kikac

Thank you

I think the only way is with hydraulic press and the right size bushes (90mm)
Have you heated the rear axle before pressing the new rubbers?

@Kikac
Yes we are using a hydraulic press.
We don't heated the rear axle. The mechanic is worried to damage the new rubbers
Do you have experience on that point?

[Kikac]

Originally Posted by Thomas911

@Kikac
Yes we are using a hydraulic press.
We don't heated the rear axle. The mechanic is worried to damage the new rubbers
Do you have experience on that point?

Not much experience , only once on a older car where i can remember the mechanic heated the axle
before pressing the rubber.

do you have updates? Hope you will sort it out soon , can imagine you are now without car

[Thomas911]

Hello
Yes, my BMW is still at the mechanic :-/
I should get it friday .
I really hope it will solve this vibration issue

[Kikac]

That is good to hear. Can you let us know what the mechanic did now without braking the new rubber. btw, Where are you from? maybe i can do the modification at this place to my car as well