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 > Mechanical Maintenance: Break-in / Oil & Fluids / Servicing
 
Evolve Automotive
Post Reply
 
Thread Tools Search this Thread
      10-20-2011, 01:28 PM   #45
Singletrack
4th down; 4th quarter? Renegade.
 
Singletrack's Avatar
 
Drives: 09 SSII E92 M3; 12 AW X5d
Join Date: Aug 2008
Location: Pittsburgh, PA

Posts: 3,813
iTrader: (3)

Quote:
Originally Posted by Zba View Post
No prob
Yes - thanks!
Singletrack is offline   United_States
0
Reply With Quote
      11-02-2011, 02:55 PM   #46
aussie2u
New Member
 
Drives: 2011 M3 Convertible
Join Date: Nov 2011
Location: Atlanta

Posts: 6
iTrader: (0)

E93 differential bolt just snapped too!

Hi everyone, my first posting here. Found you via a google search as I wanted to see if anyone else had this problem. Low and behold, you have....

I have a completely stock 2011 E93 M3 convertible. Upon shifting quickly into 2nd last week with traction control on, i heard a loud "thud" at the rear of the car. driving at that point seemed fine until I let off or applied throttle. Each application would produce the "thud" so I knew something must have let loose.

Dealership looked at the underneath and service manager immediately pulled out a broken bolt - snapped off! He asked if I had any work done on the car and I have not. Completely stock with 13k miles. He says the probable culprit is the traction control under full power. He feels that the time between the tires wanting to spin and the brakes clamping creates enormous torque that is absorbed by these bolts. Either that or they were improperly torqued from the factory.

I could tell there was slight resistance from him wanting to replace the entire subframe due to the bolt "hollowing out" its mounting point. But considering it's completely stock, he agreed and the replacement was covered under the warranty.

Just wanted to pass this on so you wouldn't feel you were the only one like I did.



aussie2u is offline  
0
Reply With Quote
      11-02-2011, 03:02 PM   #47
stefan
Colonel
 
stefan's Avatar
 
Drives: E92M3
Join Date: Feb 2008
Location: Calgary

Posts: 2,147
iTrader: (2)

Garage List
1999 VF BMW M3  [5.00]
2001 BMW M5  [0.00]
2008 135i  [5.00]
2003 M3  [3.10]
2011.75 BMW M3  [4.17]
2009 STi  [3.83]
Quote:
Originally Posted by aussie2u View Post
Completely stock with 13k miles. He says the probable culprit is the traction control under full power. He feels that the time between the tires wanting to spin and the brakes clamping creates enormous torque that is absorbed by these bolts. Either that or they were improperly torqued from the factory.
Interesting. It's like the E46 subframe problem all over again; they beefed by the subframe and now all the stress is being transferred to the bolt. I think the theories he suggests are quite reasonable. All the more reason to use MDM! Thanks for the info.
__________________
///M Power - 2011.75 LMB M3 6MT (fuelly)
stefan is offline   Canada
0
Reply With Quote
      11-02-2011, 03:05 PM   #48
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

The bolts are galvaluminized steel like most of the undercarriage fasteners. 10.9 is almost the baddest of the BAMF fastener specs so it might just be too small
__________________

Last edited by Richbot; 11-02-2011 at 03:33 PM.
Richbot is offline  
0
Reply With Quote
      11-02-2011, 03:31 PM   #49
e92zero
Lieutenant
 
Drives: 2011 E92 BW
Join Date: May 2010
Location: somewhere in US

Posts: 544
iTrader: (0)

long shot solution but if the subframe is beefed up already, is it possible for us to upgrade the bolts alone?
e92zero is offline  
0
Reply With Quote
      11-02-2011, 03:34 PM   #50
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

I was just looking into that. I can't find 12.9 bolts in M12x100 body fit (partial thread) anywhere

A4-70 stainless has a lower tensile and yield strength than 10.9, but it might be more resilient than carbon steel, so that's a possibility
__________________
Richbot is offline  
0
Reply With Quote
      11-02-2011, 03:43 PM   #51
e92zero
Lieutenant
 
Drives: 2011 E92 BW
Join Date: May 2010
Location: somewhere in US

Posts: 544
iTrader: (0)

I don't know much about bolts but what about this one here:

http://www.theboltholder.co.nz/brows...649/index.aspx

They seem to have one in M12x100? Would these work? They are not galvaluminized though.
e92zero is offline  
0
Reply With Quote
      11-02-2011, 03:45 PM   #52
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

The other thing I was thinking about was a socket head shoulder bolt with a 90mm-ish shoulder, it'd use a smaller M10 nut but would be strong where it counts

For those whose bolts have broken, where is it breaking? I'm assuming at the nut but I could be wrong

That's a promising source, would just need washers since they're not flange bolts but I don't think there is such an animal as a galvalume flanged M12x100 body-fit partial thread bolt in 12.9 or ASME/SAE grade 9

Well, a 12.9 socket head cap screw seems like the best bet, that new zealand site isn't very informative and he's probably selling SHCS's. Yield stress is 60MPa higher on than the minimum tensile stress of the 10.9 bolt but not sure how brittle they are. I would really want to know more abuot the failure mode before I changed anything.
__________________

Last edited by Richbot; 11-02-2011 at 04:02 PM.
Richbot is offline  
0
Reply With Quote
      11-02-2011, 03:55 PM   #53
e92zero
Lieutenant
 
Drives: 2011 E92 BW
Join Date: May 2010
Location: somewhere in US

Posts: 544
iTrader: (0)

A bit off topic but if this indeed is the weakspot, I wonder how the existing and the new M5 rear end is doing better than us? Doesn't the M5 engines have more torque? The leverage point on the diff is different?
e92zero is offline  
0
Reply With Quote
      11-03-2011, 08:04 AM   #54
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

More torque and it probably shifts harder in S6 than any 6MT driver, it's VIOLENT. I bet M5's have softer/bigger bushings, they definitely have a different subframe arrangement, and there aren't very many of them and even fewer are driven hard very often. The M5 uses an M16 bolt instead of an M14 bolt for the rear mount and the front mounts appear beefier (maybe hydroformed instead of stamped, and larger) and hang down less than the mounting ears on the M3. The M3's mounting ears might be twisting quite a bit more than on the M5 which are basically rigid mounts with bushes. I wonder if this is where Malek is focusing his reinforcement kit. The M5 also uses shorter M12 bolts on the front. A couple of pieces of 1/4" plate and some longer 12.9 bolts could do the trick.

I don't see many DCT owners in this thread so I think that's part of it too, even though it's herky-jerky feeling sometimes the SMGIII is probably still better than most 6MT drivers from a drivetrain protection standpoint.
__________________

Last edited by Richbot; 11-03-2011 at 08:19 AM.
Richbot is offline  
0
Reply With Quote
      11-03-2011, 12:06 PM   #55
1SICKM
Captain
 
1SICKM's Avatar
 
Drives: 2009 M3 E92
Join Date: Oct 2010
Location: Mansfield, NJ

Posts: 953
iTrader: (5)

this is a fluke accident. Many of us are running superchargers with 500-600 whp on DCT and no problems! Hope everything works out...its should since your warranty covers this.
__________________
E92 M3 DCT...Powered by ESS VT2 650/DCT GTS Software/Aquamist HFS-3 50/50/Morr /Toyo R888's

CURRENT WORLD RECORD HOLDER 1/4 MILE - 12/7/12 (ESS VT2 625, Meth Off)
ATCO RACEWAY: 10.65 @ 131.79MPH 1.725 60FT
1SICKM is offline  
0
Reply With Quote
      11-03-2011, 12:37 PM   #56
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

I doubt many DCT cars will show up with this problem. As far as I can tell, nobody who has reported it has a DCT
__________________
Richbot is offline  
0
Reply With Quote
      11-03-2011, 01:13 PM   #57
stefan
Colonel
 
stefan's Avatar
 
Drives: E92M3
Join Date: Feb 2008
Location: Calgary

Posts: 2,147
iTrader: (2)

Garage List
1999 VF BMW M3  [5.00]
2001 BMW M5  [0.00]
2008 135i  [5.00]
2003 M3  [3.10]
2011.75 BMW M3  [4.17]
2009 STi  [3.83]
Quote:
Originally Posted by 1SICKM View Post
this is a fluke accident. Many of us are running superchargers with 500-600 whp on DCT and no problems! Hope everything works out...its should since your warranty covers this.
Careful.. disregard such as that is exactly how things started with the E46 subframe. Of course; not EVERY E46 M3 had this problem. But it became widespread enough that it was eventually a recall. It has occurred to me that we have been dodging around this issue, but there have been a notable number of bolt failures here on this forum. Clarification: I do not think we are seeing something on THAT scale. It won't be a recall.. but still.

Quote:
Originally Posted by Richbot View Post
I doubt many DCT cars will show up with this problem. As far as I can tell, nobody who has reported it has a DCT
There have been a few DCTers with this, but it was blamed on a bad exhaust installation (apparently some shops were taking off the diff bolt and reinstalling it incorrectly).
__________________
///M Power - 2011.75 LMB M3 6MT (fuelly)

Last edited by stefan; 11-03-2011 at 01:22 PM.
stefan is offline   Canada
0
Reply With Quote
      11-03-2011, 01:17 PM   #58
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

Well that's good and bad I guess. Bad for them but good to know it's not purely a human issue.
__________________
Richbot is offline  
0
Reply With Quote
      11-03-2011, 01:20 PM   #59
stefan
Colonel
 
stefan's Avatar
 
Drives: E92M3
Join Date: Feb 2008
Location: Calgary

Posts: 2,147
iTrader: (2)

Garage List
1999 VF BMW M3  [5.00]
2001 BMW M5  [0.00]
2008 135i  [5.00]
2003 M3  [3.10]
2011.75 BMW M3  [4.17]
2009 STi  [3.83]
A few from a very quick search. There's more but I'd have to dig.
http://www.m3post.com/forums/showthread.php?t=549268
http://www.m3post.com/forums/showthread.php?t=536754
http://www.m3post.com/forums/showthread.php?t=547435
http://www.m3post.com/forums/showthread.php?t=593441

Quote:
Originally Posted by Richbot View Post
Well that's good and bad I guess. Bad for them but good to know it's not purely a human issue.
Indeed. Certainly no more of a human issue than the E46 m3 subframe recall was.
__________________
///M Power - 2011.75 LMB M3 6MT (fuelly)
stefan is offline   Canada
0
Reply With Quote
      11-03-2011, 01:42 PM   #60
Richbot
Colonel
 
Drives: Jerez Black E90
Join Date: Sep 2007
Location: STL

Posts: 2,036
iTrader: (2)

Quote:
Originally Posted by stefan View Post
A few from a very quick search. There's more but I'd have to dig.
http://www.m3post.com/forums/showthread.php?t=549268
http://www.m3post.com/forums/showthread.php?t=536754
http://www.m3post.com/forums/showthread.php?t=547435
http://www.m3post.com/forums/showthread.php?t=593441

Indeed. Certainly no more of a human issue than the E46 m3 subframe recall was.
Those were all 6MT cars, at least the original posters were.
__________________
Richbot is offline  
0
Reply With Quote
      11-03-2011, 03:06 PM   #61
e92zero
Lieutenant
 
Drives: 2011 E92 BW
Join Date: May 2010
Location: somewhere in US

Posts: 544
iTrader: (0)

hmm, I hope we can find a long term solution, brace or stronger bolts cause I plan to keep this car for a long time and hate to see this fail out of waranty (or keep coming back). I will check my bolts this weekend and report back if it's lose or not.

^Richbot, thanks for the explanation and knowledge.
e92zero is offline  
0
Reply With Quote
      11-03-2011, 03:10 PM   #62
Inputflangeman
New Member
 
Drives: 2011 BMW M3 E90
Join Date: Nov 2011
Location: Sugar Grove, IL

Posts: 10
iTrader: (0)

Now I'm curious. About 3 months ago, I got out of my car and I heard a very loud "ping" coming from the rear of my car. It had the definite sound of metal shearing. Subsequently, when I got out of the store and started driving, it sounded like I was dragging a large can of Folger's coffee behind my car. It was loud. I got out expecting to see the exhaust hanging on the ground, but, nothing was visibly amiss. I started driving again, and the sound went away after about a block of driving. BTW - I only have 6,000 miles on it.

I took it to the dealer and they did a cursury look at it and found nothing. Ever since this pining event though, I do occassionally get a strange groaning noise from the rear end, usually when the car is cold and when I have the steering wheel turn hard to the right and at slow speed.

I'm wondering now, because I have also read the threads about the special differential fluid, whether I have broken something or just need the new oil. I'm not a master mechanic, have not done a quick launch, and drive it pretty conservatively. How easy/hard is it to check the bolts? Anybody have an better close ups of the diff case indicating exactly where the bolt is located? I saw the previous poster's picture, but, it doesn't narrow it down enough for me? Any help would be greatly appreciated!

Last edited by Inputflangeman; 11-03-2011 at 03:22 PM.
Inputflangeman is offline  
0
Reply With Quote
      11-03-2011, 03:31 PM   #63
e92zero
Lieutenant
 
Drives: 2011 E92 BW
Join Date: May 2010
Location: somewhere in US

Posts: 544
iTrader: (0)

Borrowing from the pictures from the DIY for exhaust installation, here is the bolt that's in question. One on each side of the diff:

http://www.bimmerpost.com/forums/att...1&d=1252375403

http://www.bimmerpost.com/forums/att...3&d=1252375584

http://www.bimmerpost.com/forums/att...4&d=1252375584
e92zero is offline  
0
Reply With Quote
      11-03-2011, 03:33 PM   #64
Inputflangeman
New Member
 
Drives: 2011 BMW M3 E90
Join Date: Nov 2011
Location: Sugar Grove, IL

Posts: 10
iTrader: (0)

Quote:
Originally Posted by e92zero View Post
Borrowing from the pictures from the DIY for exhaust installation, here is the bolt that's in question. One on each side of the diff:

http://www.bimmerpost.com/forums/att...1&d=1252375403

http://www.bimmerpost.com/forums/att...3&d=1252375584

http://www.bimmerpost.com/forums/att...4&d=1252375584
Sweet, thanks! I'll check them first, if they are not broken or loose, I will go to the dealer and get the special diff sauce!
Inputflangeman is offline  
0
Reply With Quote
      11-03-2011, 03:35 PM   #65
NYCM3ryder
Razzor
 
Drives: JB E90 M3
Join Date: Aug 2010
Location: New York City

Posts: 513
iTrader: (0)

i had the same issue bro on my e90... the bolt snapped and it felt like my rear diff was going to fall off. I had the dealer take care of it.. they said it was covered by warranty so no issue...
__________________

2011 E90, 6 speed, technology package, black 220 rims , EDC, moon roof, matt black grills, matte side grills, 15% carbon tints, carbon fiber M pedals, ACS roof wing, IND painted reflectors, mfest black gloss m3badges, Mfest side window stickers, Tuner MS 15mm spacers, Carbon fiber M foot pedals, MS air filter, RPI air scoops, euro switch mod
NYCM3ryder is offline   United_States
0
Reply With Quote
      11-03-2011, 05:47 PM   #66
elp_jc
Brigadier General
 
Drives: .
Join Date: May 2008
Location: .

Posts: 4,910
iTrader: (0)

Quote:
Originally Posted by aussie2u View Post
I could tell there was slight resistance from him wanting to replace the entire subframe due to the bolt "hollowing out" its mounting point.
What exactly happened to the subframe, and/or differential mounting point??? If bolt just snapped, everything else should be perfect. Something doesn't add up. If something else broke (either differential mount and/or subframe), that could have caused the bolt to snap. We need more information. Any pics man?

Quote:
Originally Posted by aussie2u View Post
He says the probable culprit is the traction control under full power. He feels that the time between the tires wanting to spin and the brakes clamping creates enormous torque that is absorbed by these bolts.
TC only acts on the engine, by cutting timing, or fuel if needed. Brakes are only applied by DSC. What's causing the problem has to be AXLE HOP IMO.

And keep in mind if something else broke besides the bolt, it has to be investigated what failed first. My money is on defective bolts, but could be improper torquing, or even defective subframes and/or differential mounts. In the mean time, can somebody post pics of exactly what's breaking??? Thx.

Quote:
Originally Posted by e92zero View Post
I will check my bolts this weekend and report back if it's lose or not.
Hey, do you have the torque spec those 2 bolts? I want to check mine too just for the hell of it, but I suspect improper torque might not be the most likely cause since it happened to a stock car... but you never know.

As a side comment, to properly check torque, fastener has to be loosened up first, then retightened. But I'll check torque on the fastened nut first. If torque wrench clicks without moving, even if not torqued to spec, it's probably not enough to cause the problem IMO. Hope we hear the real cause of this, although I'm not too concerned, since I never launch my car. And without axle hop, I'm sure my car will never fail like that. But it still shouldn't happen; that's for sure. Good day gang.
elp_jc is offline   United_States
0
Reply With Quote
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 -5. The time now is 01:32 AM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, 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