Need help diagnosing vibration

Darkne55 · 10-03-2023, 07:11 AM

Hi,

I carried out a few DIY jobs on my E92 M3.
- Replaced DCT mechatronic sleeve rubber o-ring.
- Replaced mechatronic side cover rubber gasket
- Replaced the pan and DCT fluid also.

This was done while the car is on jacks. The drive shaft was disconnected from the guibo and dct support mount was removed to lower the DCT transmission so that i can access the mechatronic sleeve. The DCT was supported by a jack and it lowered a few inches, enough to fit my hand above.

After reinstalled everything and test drove the car. There is very noticible vibration as the car takes off and the vibration gets worse as the RPM increases. Tested in lower gears 1,2 and 3 reving up to 3000 - 4000rpm. And at that rpm, the vibration is very prominant and quiet scary so i did not go any higher. I also notice that if revs are kep low and up shift into higher gears the car can get up to decent speed (60 kmph). Still slight vibration there but not as violently as driving with high rpms.

I am wondering if this is drive shaft related.
When i was reinstalling the drive shaft and the center bearing, I followed the torque specifications.

Guibo to drive shaft 55 NM (41 ft lb) plus 90 degrees
Center bearing support bracket 21 NM (15 ft lb)

- Is there any specific order to install the drive shaft? example, tighten down center bearing first and the drive shatf to guibo.
- When reconnecting the drive shaft to guibo, I am not sure if the same holes on drive shaft to guibo was used. As i forgot to mark it when i was disconnecting the drive shft. Would this cause any vibrations.

Any suggestions or tips on where to check would be much appreciated.

Thanks

tdott · 10-03-2023, 10:40 AM

sounds like you might have put the drive shalf csb in upside down, I would take it apart and inspect everything driveshalf related.

Darkne55 · 10-03-2023, 04:22 PM

Thanks, I will look into it further. I did have a quick pause when remounting the csb as I was not 100% which way is up. I noticed that there is a small raised section on the csb itself, like a little bump to indicate which direction it should be facing, either the bump facing up or facing down. I watch a few videos and photos on the web and did not see that bump when you look up from bottom of the car, so I installed the csb with that little bump facing upward, towards the body of the car.

If anyone can confirm which way is the correct way would be much appreciated.

amrazM · 10-05-2023, 04:18 AM

engine mounts broke is my guess. its easy to tell if you installed the csb upside down, usually its apparent when putting on the heatshields.

tdott · 10-05-2023, 08:54 AM

Quote:

Originally Posted by Darkne55

Thanks, I will look into it further. I did have a quick pause when remounting the csb as I was not 100% which way is up. I noticed that there is a small raised section on the csb itself, like a little bump to indicate which direction it should be facing, either the bump facing up or facing down. I watch a few videos and photos on the web and did not see that bump when you look up from bottom of the car, so I installed the csb with that little bump facing upward, towards the body of the car.

If anyone can confirm which way is the correct way would be much appreciated.

It should be marked.

Darkne55 · 10-11-2023, 06:46 AM

Thanks for your replies.

I got the issue resolved at the end. I did rush through the reassembly that a few items were overlooked.

I got the car on jacks to inspect everything that I worked on. First issue I found was the aluminium skid plate was touching the engine oil sump, near the jacking point. I had to use rubber mullet to correct that.
Second thing was to check the csb orientation. I had it installed correctly so that was not the case. But I remounted the csb and made sure there is preload to it. Read that this is done on older models (E36, E46) also.

Tested the car after these done and the vibration was no longer there. Thank goodness. Was regretting taking on this DIY but now I’m glad it got done and car also back to normal. Waiting for the weekend to have a proper outing

10-03-2023, 07:11 AM	#1
Darkne55 Private First Class 30 Rep 101 Posts Drives: 2009 E92 M3 Join Date: Oct 2015 Location: NSW iTrader: (0)	Need help diagnosing vibration Hi, I carried out a few DIY jobs on my E92 M3. - Replaced DCT mechatronic sleeve rubber o-ring. - Replaced mechatronic side cover rubber gasket - Replaced the pan and DCT fluid also. This was done while the car is on jacks. The drive shaft was disconnected from the guibo and dct support mount was removed to lower the DCT transmission so that i can access the mechatronic sleeve. The DCT was supported by a jack and it lowered a few inches, enough to fit my hand above. After reinstalled everything and test drove the car. There is very noticible vibration as the car takes off and the vibration gets worse as the RPM increases. Tested in lower gears 1,2 and 3 reving up to 3000 - 4000rpm. And at that rpm, the vibration is very prominant and quiet scary so i did not go any higher. I also notice that if revs are kep low and up shift into higher gears the car can get up to decent speed (60 kmph). Still slight vibration there but not as violently as driving with high rpms. I am wondering if this is drive shaft related. When i was reinstalling the drive shaft and the center bearing, I followed the torque specifications. Guibo to drive shaft 55 NM (41 ft lb) plus 90 degrees Center bearing support bracket 21 NM (15 ft lb) - Is there any specific order to install the drive shaft? example, tighten down center bearing first and the drive shatf to guibo. - When reconnecting the drive shaft to guibo, I am not sure if the same holes on drive shaft to guibo was used. As i forgot to mark it when i was disconnecting the drive shft. Would this cause any vibrations. Any suggestions or tips on where to check would be much appreciated. Thanks __________________ 2009 E92 Jarez Black M3 2018 G01 X3 xDrive20d
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10-03-2023, 10:40 AM	#2
tdott S.FL S65 Specialist 4464 Rep 4,313 Posts Drives: M3 Join Date: Nov 2010 Location: South FL / 6ix iTrader: (4)	sounds like you might have put the drive shalf csb in upside down, I would take it apart and inspect everything driveshalf related. __________________ N/A S65 Headers Before/After Dyno Results tdott's Spec E9X Build Thread https://www.youtube.com/@tdottme
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10-03-2023, 04:22 PM	#3
Darkne55 Private First Class 30 Rep 101 Posts Drives: 2009 E92 M3 Join Date: Oct 2015 Location: NSW iTrader: (0)	Thanks, I will look into it further. I did have a quick pause when remounting the csb as I was not 100% which way is up. I noticed that there is a small raised section on the csb itself, like a little bump to indicate which direction it should be facing, either the bump facing up or facing down. I watch a few videos and photos on the web and did not see that bump when you look up from bottom of the car, so I installed the csb with that little bump facing upward, towards the body of the car. If anyone can confirm which way is the correct way would be much appreciated.
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10-05-2023, 04:18 AM	#4
amrazM mTekMods 2431 Rep 3,138 Posts Drives: like a granny. Join Date: Jan 2010 Location: Manhatan iTrader: (1)	engine mounts broke is my guess. its easy to tell if you installed the csb upside down, usually its apparent when putting on the heatshields. __________________ E90M3 - Satin Black F97 X3M - Brooklyn Grey E39 M5 - Silverstone
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10-11-2023, 06:46 AM	#6
Darkne55 Private First Class 30 Rep 101 Posts Drives: 2009 E92 M3 Join Date: Oct 2015 Location: NSW iTrader: (0)	Thanks for your replies. I got the issue resolved at the end. I did rush through the reassembly that a few items were overlooked. I got the car on jacks to inspect everything that I worked on. First issue I found was the aluminium skid plate was touching the engine oil sump, near the jacking point. I had to use rubber mullet to correct that. Second thing was to check the csb orientation. I had it installed correctly so that was not the case. But I remounted the csb and made sure there is preload to it. Read that this is done on older models (E36, E46) also. Tested the car after these done and the vibration was no longer there. Thank goodness. Was regretting taking on this DIY but now I’m glad it got done and car also back to normal. Waiting for the weekend to have a proper outing
	Appreciate 0 Quote