02-09-2017, 05:05 PM | #1 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
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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. |
02-09-2017, 07:30 PM | #4 | |
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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! |
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02-10-2017, 06:08 AM | #6 |
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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.
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02-10-2017, 07:23 AM | #7 | |
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02-10-2017, 08:24 AM | #8 |
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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:
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02-11-2017, 12:48 AM | #9 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
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Well this got ugly quick:
Driveshaft sheared off Diff mounts broken (obviously) Fuel tank heat shield broken Some bolts stuck here and there ?!? $$$$$$ |
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02-11-2017, 07:34 AM | #12 |
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02-11-2017, 08:04 AM | #13 | |
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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? |
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02-11-2017, 12:44 PM | #15 |
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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.
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02-11-2017, 02:09 PM | #16 |
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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....
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02-12-2017, 02:52 PM | #20 |
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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
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02-12-2017, 03:14 PM | #21 |
F10 1/4 WR: 9.9s / 142.5mph 1/2 WR: 175.5mph
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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.
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