F33 knocking in rear drivetrain/axle after launch

no_hands · 08-03-2022, 09:14 PM

As the title states, launched it from a green light and immediately heard a loud bang from the rear end followed by the sound from the video below. Does not make the sound in park, only when in gear (including neutral). Car rolls as well unless ebrake is engaged. Tech said the driveshaft looks fine visually and it's only the axle.

New axle is on the way but I'm worried after that's fixed that I'll need to replace the driveshaft or diff as well. Any insight would be greatly appreciated.

Car is on H&R sport springs, 19" wheels, BM3 stage 1 tune with a catless DP. Barely making 400hp.

Anyone ever seen this happen on a basically stock drivetrain?

https://youtube.com/shorts/OPnMHZecsCc?feature=share

no_hands · 08-06-2022, 09:56 PM

Quote:

Originally Posted by no_hands

As the title states, launched it from a green light and immediately heard a loud bang from the rear end followed by the sound from the video below. Does not make the sound in park, only when in gear (including neutral). Car rolls as well unless ebrake is engaged. Tech said the driveshaft looks fine visually and it's only the axle.

New axle is on the way but I'm worried after that's fixed that I'll need to replace the driveshaft or diff as well. Any insight would be greatly appreciated.

Car is on H&R sport springs, 19" wheels, BM3 stage 1 tune with a catless DP. Barely making 400hp.

Anyone ever seen this happen on a basically stock drivetrain?

https://youtube.com/shorts/OPnMHZecsCc?feature=share

Any suggestions???

n55david · 08-06-2022, 11:29 PM

Nah, you'll be fine

no_hands · 08-06-2022, 11:32 PM

Quote:

Originally Posted by n55david

Nah, you'll be fine

great advice, thanks!

n55david · 08-06-2022, 11:39 PM

Quote:

Originally Posted by no_hands

great advice, thanks!

I mean lol I can't tell if that's sarcasm
Extremely unlikely you did any other damage. You'd need to be on a different turbo and lots of e85 with a slick etc

MTWO · 08-07-2022, 06:10 AM

You’ll be fine but driveshaft can and has snapped on many people with hard launches and wheel hop, especially 6MT as you can’t preload the transmission.

08-03-2022, 09:14 PM	#1
no_hands New Member 3 Rep 28 Posts Drives: BMW 2 series Join Date: Jul 2019 Location: NY iTrader: (0) Garage List 2016 BMW 435i F33 [0.00]	F33 knocking in rear drivetrain/axle after launch As the title states, launched it from a green light and immediately heard a loud bang from the rear end followed by the sound from the video below. Does not make the sound in park, only when in gear (including neutral). Car rolls as well unless ebrake is engaged. Tech said the driveshaft looks fine visually and it's only the axle. New axle is on the way but I'm worried after that's fixed that I'll need to replace the driveshaft or diff as well. Any insight would be greatly appreciated. Car is on H&R sport springs, 19" wheels, BM3 stage 1 tune with a catless DP. Barely making 400hp. Anyone ever seen this happen on a basically stock drivetrain? https://youtube.com/shorts/OPnMHZecsCc?feature=share Attached Images
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08-06-2022, 11:29 PM	#3
n55david Check out my Youtube @n55david! 1305 Rep 3,554 Posts Drives: 2017 m240i, 2015 X3 x35i Join Date: Aug 2018 Location: Michigan USA iTrader: (0) Garage List 2017 m240i xDrive [0.00] 2015 X3 x35i [0.00] 2015 335i xdrive [0.00]	Nah, you'll be fine __________________ 2017 m240i xDrive 10.67@132.32mph w/bm3 2015 335i xDrive 10.95@124.99mph w/bm3 - SOLD 2015 X3 x35i pwg 12.96 catless w/bm3 stage 2 93 ots IG: @n55david For pics and updates! Youtube: @ n55david For videos or Racing etc
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08-07-2022, 06:10 AM	#6
MTWO Captain 473 Rep 932 Posts Drives: M2 Join Date: Dec 2016 Location: Innisfil iTrader: (0)	You’ll be fine but driveshaft can and has snapped on many people with hard launches and wheel hop, especially 6MT as you can’t preload the transmission.
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