BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications
 
Post Reply
 
Thread Tools Search this Thread
      02-28-2016, 09:28 PM   #1
DR-JEKL
Brigadier General
Australia
241
Rep
4,697
Posts

Drives: Space Grey E92 335i 6MT
Join Date: Jul 2012
Location: Newcastle Ozstraylia

iTrader: (3)

E9X M3 diff flange bolts counterbalances!?!

Hey guys

I have a 335i and have recently installed a complete driveline from a M3 into my car. This retrofit conversion has been commonplace for years now and the workshop who performed this conversion for me had done at least 4 of them in the past.

It largely all bolts up but to mate the diff up a custom driveshaft had to be manufactured as my 335i shaft wouldn't fit the M3 Diff flange. I purchased a E38 driveshaft (the 540i and 740i share the same type of diff flange to the M3) and the rear portion of my 335i was cut and the 740i section was welded to the shaft and balanced by a driveline specialist.

Upon driving the car above 80 km/h I was experiencing a humming vibration through the car (Seats, steering wheel etc) and it didn't dissapear at 140 km/h or when i applied the throttle or backed off the throttle.. It sounded like it was an out of balance driveshaft...

I was initially perturbed that a driveshaft would be cut n shut and welded as this sounded like a crude method, but alas there have been many conversions conducted on 135/335i around the world and this is the method they used...

Now to get to the reason for creating this thread and how it may be of relevance to you E9X M3 owners!

Discussing this issue with a fellow enthusiast who is a tech head and dabbles in a lot of coding, tweaking, research he came across some info in the BMW ISTA that may be the reason for my driveline vibration..

Apparently the driveline is setup to quite fine tolerances and each diff is balanced after assembly (you'll see a little round recess drilled in the flange - this is the method of correction where material is removed from the point of imbalance to ensure its precisely balanced)

drilling of the flange to remove imbalance:



In addition to the machining of the diff flange for balancing correction, there is counterbalancing on the bolts where the driveshaft connects to the diff flange as required for fine corrections (i.e if they cant get the diff perfectly balanced at the factory the technician marks the diff as OK or requiring addition counterbalancing - this is determined by the coloured mark on the diff)







Example of marks:



prior to 09/09 the counterbalancing was done with the use of washers on the marked hole )as indicated by the colour mark by the bmw factory tech) or after 09/09 special bolts once again as indicated by the colour marks. The diff I had was from a 2011 build M3 so if it required counterbalacing, it would require bolts.



bmw part #26112284154 black
bmw part #26112284153 green
black bolt is for blue marking
green is for yellow marking
if diff has white marking no counterbalance bolts required

My local BMW dealer (I'm in Australia) got me some prices for these bolts, he had some trouble as they weren't in the system as it seems no-one has ever ordered them and he discussed it with the workshop foreman who said they weren't aware of these counterbalance bolts..

They're a special order from Germany, and since I have no markings visible on my diff I would have to order both and attempt to find the orientation they should be mounted by installing driving the car and checking and removing and changing the position etc (not an easy task to do...)





*Quoted prices in AUD not USD*

I'm hoping the car doesn't need these bolts, as my diff has no marks so it will be a long process in attempting to locate the correct position on the flange which requires the counterbalance bolt.

My local BMW workshop foreman stated that they treat the diff flange bolts as a once use item (even though BMW procedures don't stipulate that the need to be replaced) and was unaware of the counterbalance bolts or washers...

Have any of you M3 owners ever been aware of the counterbalance bolts or washers?!?!

Last edited by DR-JEKL; 02-28-2016 at 09:35 PM.
Appreciate 0
      02-29-2016, 08:28 AM   #2
Dackelone
European Editor
Dackelone's Avatar
Germany
3813
Rep
20,367
Posts

Drives: N54 e82
Join Date: Feb 2010
Location: Bayern, Germany

iTrader: (1)

Perhaps its something more simple/common like a bad center driveshaft (support)bearing that bad?

#8 in your parts diagram.

Have you tried putting your car up on a lift and driving it up past 80 kph and have a tech or two under the car to look to see whats moving/vibrating. They could use a mechanic's stethoscope to probe the driveshaft's bearing or the diff - for noises.

Dack
Appreciate 0
      02-29-2016, 09:23 AM   #3
doogee
First Lieutenant
doogee's Avatar
Canada
45
Rep
376
Posts

Drives: 08 M3, '06 325i
Join Date: Oct 2008
Location: Ancaster, ON, Canada

iTrader: (0)

You're definitely overthinking this.

Takes a few steps back and have the typical culprits checked.
Appreciate 0
      02-29-2016, 10:37 AM   #4
pbonsalb
Brigadier General
170
Rep
3,183
Posts

Drives: 08 E90 M3, 99 E36 M3 Turbo
Join Date: Feb 2011
Location: Concord, NH

iTrader: (3)

Very in depth analysis. I will try to look at mine next time it is on the lift to see which version I have.
Appreciate 0
      02-29-2016, 05:14 PM   #5
DR-JEKL
Brigadier General
Australia
241
Rep
4,697
Posts

Drives: Space Grey E92 335i 6MT
Join Date: Jul 2012
Location: Newcastle Ozstraylia

iTrader: (3)

Quote:
Originally Posted by Dackelone View Post
Perhaps its something more simple/common like a bad center driveshaft (support)bearing that bad?

#8 in your parts diagram.

Have you tried putting your car up on a lift and driving it up past 80 kph and have a tech or two under the car to look to see whats moving/vibrating. They could use a mechanic's stethoscope to probe the driveshaft's bearing or the diff - for noises.

Dack
Thanks for your reply Dack!

AFAIK the original centre bearing was re-used, so I would assume since it was fine before the driveline upgrade it would be OK now? I reside 2hrs away from the workshop so unfortunately cannot really drop in and witness for myself

I had the shaft sent out to a 2nd driveline specialist as the initial shop their balancing machine couldn't spin the shaft at a high enough RPM to see any vibration or balancing issues
Appreciate 1
      02-29-2016, 05:18 PM   #6
DR-JEKL
Brigadier General
Australia
241
Rep
4,697
Posts

Drives: Space Grey E92 335i 6MT
Join Date: Jul 2012
Location: Newcastle Ozstraylia

iTrader: (3)

Quote:
Originally Posted by doogee View Post
You're definitely overthinking this.

Takes a few steps back and have the typical culprits checked.
Hmm yup most likely, I thought of having the car up on a trolley jack and running it up to speed and having a squiz under the car albeit would be a tad dangerous to get under the car... Touch wood the 2nd shop balancing the driveshaft cures the issue!

Quote:
Originally Posted by pbonsalb View Post
Very in depth analysis. I will try to look at mine next time it is on the lift to see which version I have.
Cheers, this thread was posted to raise the awareness of the counterbalancing bolts/washers for you ///M owners as a heads up if you ever get work done on your diff to be mindful of it. Unfortunately I had no idea and never checked my diff before installing it
Appreciate 0
      02-29-2016, 07:09 PM   #7
SYT_Shadow
///M Powered for Life
United_States
139
Rep
964
Posts

Drives: 2x01 330, 02 M3, 13 ZCP M3
Join Date: Sep 2010
Location: NYC

iTrader: (1)

Unfortunately I can't help you, but the information is very interesting!!
Appreciate 0
      03-01-2016, 06:48 AM   #8
DR-JEKL
Brigadier General
Australia
241
Rep
4,697
Posts

Drives: Space Grey E92 335i 6MT
Join Date: Jul 2012
Location: Newcastle Ozstraylia

iTrader: (3)

Quote:
Originally Posted by SYT_Shadow View Post
Unfortunately I can't help you, but the information is very interesting!!
Cheers

The main reason for this post was to see if anyone else has any knowledge or experience with this counterbalancing bolts/washers and to raise the awareness for guys who may not know
Appreciate 0
      08-20-2016, 07:55 PM   #9
DR-JEKL
Brigadier General
Australia
241
Rep
4,697
Posts

Drives: Space Grey E92 335i 6MT
Join Date: Jul 2012
Location: Newcastle Ozstraylia

iTrader: (3)

FYI marconi118
Appreciate 0
      08-20-2016, 08:48 PM   #10
Bx Tpr
Captain
Bx Tpr's Avatar
United_States
23
Rep
681
Posts

Drives: '13 M
Join Date: Feb 2009
Location: NY

iTrader: (6)

Could this explain why guys are having humming noises with the CF driveshaft? Placing the colored bolts where they aren't supposed to be during install? Or do carbon driveshafts usually hum?
Appreciate 0
      08-20-2016, 10:29 PM   #11
DR-JEKL
Brigadier General
Australia
241
Rep
4,697
Posts

Drives: Space Grey E92 335i 6MT
Join Date: Jul 2012
Location: Newcastle Ozstraylia

iTrader: (3)

Quote:
Originally Posted by Bx Tpr View Post
Could this explain why guys are having humming noises with the CF driveshaft? Placing the colored bolts where they aren't supposed to be during install? Or do carbon driveshafts usually hum?
AFAIK its common trait to have added NVH with a rigid one piece cf prop due to the shaft itself.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 11:34 AM.




m3post
m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST