Differential Mount Cracked

allmotor_2000 · 02-09-2017, 05:05 PM

Folks - the inevitable happened. My differential mount cracked with a large *thud* last night rendering me stranded on the wonderful 405 freeway at 9pm. Tow truck inevitably came by 11pm during which time I met TWO CHP officers, TWO unfortunate homeless souls and ONE BMW Tuner who happened to stop by and lend a hand (guess who...)

The obvious question... what was I doing when it broke? Answer... ding ding ding... NOTHING! I was just cruising, shifted into 4th and BANG!

Anyways, car is getting repaired but this issue is like the plague and needs to be fixed. So, I will investigate and figure out a solution. It may be simple as a plate, stronger bolts... whatever it is.

SapphireM5 · 02-09-2017, 05:41 PM

Oh man that sucks! GL with the repair

ARC550 · 02-09-2017, 07:20 PM

Wow! I guess it was in it's last thread ! Ahhahaha

To stiff = snap ? No?

Need to have some give

Used2be · 02-09-2017, 07:30 PM

Quote:

Originally Posted by allmotor_2000

Anyways, car is getting repaired but this issue is like the plague and needs to be fixed. So, I will investigate and figure out a solution. It may be simple as a plate, stronger bolts... whatever it is.

One of the New York area posters had something in the works for this, quite a while ago I think? Hadn't he broken two of the cast mounting structures? Also, didn't the car from Costa Rica (sorry, can't remember the country for sure) have this failure? He did a weld up repair, but had a new replacement coming.

If possible, could you show us pictures of the removed broken part? That might give us a good reference to look for initial cracking before failure. You guys with the high horsepower are playing with fire. So sorry for the hassle!

Drm5 · 02-10-2017, 05:54 AM

I just finish changing mine... I might order a new mount 190.00 an see if someone can forge one ..!!

Used2be · 02-10-2017, 06:08 AM

Quote:

Originally Posted by Drm5

I just finish changing mine... I might order a new mount 190.00 an see if someone can forge one ..!!

Sorry, it was Puerto Rico, bad memory! I'd think making a jig and welding up some plates for a whole new structure would be more practical than a complete forged piece. Or, strategically placed supporting gussets welded on to the stock piece. Still, not a simple project, but if it's going to be a consistently weak point that fails for those of you with higher HP, it needs to be done.

M5 London · 02-10-2017, 07:23 AM

Quote:

Originally Posted by allmotor_2000

Tow truck inevitably came by 11pm during which time I met TWO CHP officers, TWO unfortunate homeless souls and ONE BMW Tuner who happened to stop by and lend a hand (guess who...)

Steve Dinan ?

jairomvp182 · 02-10-2017, 08:24 AM

Quote:

Originally Posted by M5 London

Steve Dinan ?

he would of said, you know i can make your car fast and reliable, we will give you warranty, our power delivery is so smooth that you wont be braking parts, all that for 9999.99, but thats not all, if you order now i will include 2 stickers and one license plate frame

: happyanim:

allmotor_2000 · 02-11-2017, 12:48 AM

Well this got ugly quick:

Driveshaft sheared off
Diff mounts broken (obviously)
Fuel tank heat shield broken
Some bolts stuck here and there ?!?

$$$$$$

Drm5 · 02-11-2017, 06:06 AM

I just replaced the welded one for a new one...here are some pic...

evilb · 02-11-2017, 06:28 AM

Subscribing

KMORGSM5 · 02-11-2017, 07:34 AM

Quote:

Originally Posted by allmotor_2000

Well this got ugly quick:

Driveshaft sheared off
Diff mounts broken (obviously)
Fuel tank heat shield broken
Some bolts stuck here and there ?!?

$$$$$$

Ah damn man sorry to hear that

Used2be · 02-11-2017, 08:04 AM

Quote:

Originally Posted by Drm5

I just replaced the welded one for a new one...here are some pic...

Just a complete guess, but is the large rubber bushing used to isolate the chassis from road noise, vibration? With more torque applied to the wheels than designed for, does the piece twist, putting enough force to the smaller ear with the bolt through it, to break it? Was the bolt also broken through the small repaired ear?

Would making the large diameter bore more stable allow the part to survive? Would changing the style of bushing from this flexible rubber to a more rigid material help? Or, would that just change the failure point? Would the added rigidity only make things worse? And perhaps bring a lot of road noise into the passenger area?

Throwing thoughts out there for the more knowledgable types to chew on. It will be informative if Allmotor's failure was the same. Is there any structural damage to the differential itself?

TrevorM3 · 02-11-2017, 08:44 AM

So this has nothing to do with the power output of your car?

MrPowell · 02-11-2017, 12:44 PM

Wow sorry to hear Ram, esp the collateral damage the came along with it. Hopefully someone can figure out a stronger mount to stop this from happening again.

apexlocator · 02-11-2017, 02:09 PM

Quote:

Originally Posted by allmotor_2000

Well this got ugly quick:

Driveshaft sheared off
Diff mounts broken (obviously)
Fuel tank heat shield broken
Some bolts stuck here and there ?!?

$$$$$$

You are a pioneer. What are you running, 850wtq? I guess you've found the limit for stock driveshaft and diff mount. I'm guessing this damage happened slowly over time, and then a simple shift pushed it over. The limit may actually be lower wtq. Even though I have zero plans to go into 800s, I wonder how long 700+wtq can last....

allmotor_2000 · 02-11-2017, 04:37 PM

I need to look at the broken parts and then figure out what to do. Maybe billet mount :-)

Msizzle · 02-12-2017, 12:00 AM

subd

beach48 · 02-12-2017, 10:40 AM

subd, Billet part sounds good. Got to be a market for this as an upgraded part

momos750 · 02-12-2017, 02:52 PM

We used to use Billetflow for differential braces on our old 03-04 Cobras. He has a full CNC shop and makes solid products.
If we got him the differential mount he may be able to design and mill them with enough interest at a reasonable cost.

http://www.billetflow.com/irs_brace.htm

allmotor_2000 · 02-12-2017, 03:14 PM

Nice find - I need to see what else broke and then decide. Need to upgrade multiple weak points unless there is large gap between what breaks first and the next in line.

BPMSport · 02-13-2017, 11:48 AM

Quote:

Originally Posted by M5 London

Steve Dinan ?

It was me, of course!

It was really sketchy pulling over there - very narrow.... and I was worried my Mercedes SUV wouldn't get back up to speed to merge in time

02-09-2017, 05:05 PM	#1
allmotor_2000 F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph 1087 Rep 1,968 Posts Drives: 2018 RS3, 991 Turbo Join Date: Jul 2014 Location: Westlake Village, CA iTrader: (0)	Differential Mount Cracked Folks - the inevitable happened. My differential mount cracked with a large thud last night rendering me stranded on the wonderful 405 freeway at 9pm. Tow truck inevitably came by 11pm during which time I met TWO CHP officers, TWO unfortunate homeless souls and ONE BMW Tuner who happened to stop by and lend a hand (guess who...) The obvious question... what was I doing when it broke? Answer... ding ding ding... NOTHING! I was just cruising, shifted into 4th and BANG! Anyways, car is getting repaired but this issue is like the plague and needs to be fixed. So, I will investigate and figure out a solution. It may be simple as a plate, stronger bolts... whatever it is. Attached Images
	Appreciate 1 BPMSport3386.50 Tweet Quote

02-09-2017, 05:41 PM	#2
SapphireM5 Major 711 Rep 1,107 Posts Drives: 2013 M5 Sapphire Black Join Date: Feb 2017 Location: New Jersey iTrader: (3)	Oh man that sucks! GL with the repair
	Appreciate 0 Quote

02-09-2017, 07:20 PM	#3
ARC550 Major 446 Rep 1,300 Posts Drives: M3, X5, 720s, X5, 750xi Join Date: Nov 2013 Location: New York iTrader: (0)	Wow! I guess it was in it's last thread ! Ahhahaha To stiff = snap ? No? Need to have some give
	Appreciate 0 Quote

02-10-2017, 05:54 AM	#5
Drm5 Private First Class 30 Rep 182 Posts Drives: F10 M5 sakhir orange Join Date: Jan 2013 Location: Puerto rico iTrader: (0)	I just finish changing mine... I might order a new mount 190.00 an see if someone can forge one ..!!
	Appreciate 0 Quote

02-11-2017, 12:48 AM	#9
allmotor_2000 F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph 1087 Rep 1,968 Posts Drives: 2018 RS3, 991 Turbo Join Date: Jul 2014 Location: Westlake Village, CA iTrader: (0)	Well this got ugly quick: Driveshaft sheared off Diff mounts broken (obviously) Fuel tank heat shield broken Some bolts stuck here and there ?!? $$$$$$
	Appreciate 1 apexlocator243.00 Quote

02-11-2017, 06:06 AM	#10
Drm5 Private First Class 30 Rep 182 Posts Drives: F10 M5 sakhir orange Join Date: Jan 2013 Location: Puerto rico iTrader: (0)	I just replaced the welded one for a new one...here are some pic... Attached Images
	Appreciate 0 Quote

02-11-2017, 06:28 AM	#11
evilb Lieutenant 167 Rep 501 Posts Drives: McLaren MSO 570S, 18 Raptor Join Date: Oct 2014 Location: Raleigh-Durham, NC iTrader: (2)	Subscribing __________________ 2016 McLaren MSO 570S \| 2018 Ford Raptor \| @alpha7even
	Appreciate 0 Quote

02-11-2017, 08:44 AM	#14
TrevorM3 Banned 3322 Rep 8,083 Posts Drives: 6.3 AMG Join Date: Apr 2013 Location: Florida iTrader: (0)	So this has nothing to do with the power output of your car?
	Appreciate 1 mister2d155.50 Quote

02-11-2017, 12:44 PM	#15
MrPowell Private 26 Rep 55 Posts Drives: 2014 M5 Join Date: Dec 2015 Location: Houston, TX iTrader: (0)	Wow sorry to hear Ram, esp the collateral damage the came along with it. Hopefully someone can figure out a stronger mount to stop this from happening again. __________________ 2014 BMW M5 - JB4+BCM, BootMod3, SSP Spec-R Clutches, Gutted Stock Downpipes, K&N Drop Ins (SOLD) 2002 Porsche 996TT - EVOSpec 9000 RPM 4.0ltr w/ Xona Rotor 95-67s ... Controlled by Syvecs
	Appreciate 0 Quote

02-11-2017, 04:37 PM	#17
allmotor_2000 F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph 1087 Rep 1,968 Posts Drives: 2018 RS3, 991 Turbo Join Date: Jul 2014 Location: Westlake Village, CA iTrader: (0)	I need to look at the broken parts and then figure out what to do. Maybe billet mount :-)
	Appreciate 0 Quote

02-12-2017, 12:00 AM	#18
Msizzle Lieutenant 165 Rep 402 Posts Drives: 2013 M6 Coupe Join Date: Mar 2015 Location: Long Island, NY iTrader: (0)	subd
	Appreciate 0 Quote

02-12-2017, 10:40 AM	#19
beach48 Enlisted Member 5 Rep 32 Posts Drives: 2013 F02 760LI Join Date: Nov 2016 Location: Bristol UK iTrader: (0)	subd, Billet part sounds good. Got to be a market for this as an upgraded part
	Appreciate 0 Quote

02-12-2017, 02:52 PM	#20
momos750 Captain 143 Rep 715 Posts Drives: 2015 M5, 2011 750Li Join Date: Jul 2015 Location: CA iTrader: (0)	We used to use Billetflow for differential braces on our old 03-04 Cobras. He has a full CNC shop and makes solid products. If we got him the differential mount he may be able to design and mill them with enough interest at a reasonable cost. http://www.billetflow.com/irs_brace.htm __________________ 2015 M5 - Singapore Grey Metallic - Silverstone Full Merino Interior - Executive Pack - Drivers Assist Pack -Comp Pack -
	Appreciate 1 Redrckt135429.50 Quote

02-12-2017, 03:14 PM	#21
allmotor_2000 F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph 1087 Rep 1,968 Posts Drives: 2018 RS3, 991 Turbo Join Date: Jul 2014 Location: Westlake Village, CA iTrader: (0)	Nice find - I need to see what else broke and then decide. Need to upgrade multiple weak points unless there is large gap between what breaks first and the next in line.
	Appreciate 0 Quote