Crank Hub Issue

Phil325i · 06-11-2020, 03:46 AM

As per the title really.

Been reading about the issue with the S55 crank hub. In brief, BMW threw out the last 100 years of engine development and decided to lock the crank gear to the crankshaft with nothing more than a diamond sintered washer, and a load of torque from the crank bolt to hold the timing in place. In certain circumstances the bolt moves and no longer holds the timing accurately. As the S55 is an interference engine, the results can be catastrophic.

My question is: does anyone know if this design feature is found on other BMW engines? Looking at RealOEM it appears this may well be the case on other engine series, but I wanted to know for sure.

Cheers...

Efthreeoh · 06-11-2020, 10:20 AM

N52 is the same.

Dormermike · 06-29-2020, 05:27 PM

N53 also iirc

CTinline-six · 06-30-2020, 10:26 AM

It seems to only be an issue for engines with higher HP, especially tuned engines.

Phil325i · 06-30-2020, 11:19 AM

Quote:

Originally Posted by CTinline-six

It seems to only be an issue for engines with higher HP, especially tuned engines.

Yeah I think you're right. And as well as aftermarket 'solutions' I also picked up that BMW have modified the sprockets by introducing a band of laser etching around the circumference, presumably to increase the friction between the face of the sprocket and the crankshaft.

Js235 · 07-21-2020, 04:14 AM

I think N54 have same system

06-11-2020, 03:46 AM	#1
Phil325i Brigadier General 615 Rep 3,193 Posts Drives: E92 325i MSport Coupe Join Date: Apr 2012 Location: UK South East iTrader: (1) Garage List 2009 BMW 325i Coupe [6.00]	Crank Hub Issue - which engines affected? As per the title really. Been reading about the issue with the S55 crank hub. In brief, BMW threw out the last 100 years of engine development and decided to lock the crank gear to the crankshaft with nothing more than a diamond sintered washer, and a load of torque from the crank bolt to hold the timing in place. In certain circumstances the bolt moves and no longer holds the timing accurately. As the S55 is an interference engine, the results can be catastrophic. My question is: does anyone know if this design feature is found on other BMW engines? Looking at RealOEM it appears this may well be the case on other engine series, but I wanted to know for sure. Cheers... __________________ E92 pre-LCI 325i - Ohlins R&T; H&R spacers; M3 strut brace; Swift thrust sheets; 3 x chassis braces; diff brace; N53 V-brace; 034 subframe inserts; BMS clutch stop; BMS CDV; RE g/box mounts; Delrin shift bushes; Saikoumichi OCC; Cyba scoops; BMW Perf Exhaust; HEL s/steel brake hoses; M3 rear spoiler; Recaro Sportster CSs; M3 white dash LEDs; LED Angels; LED side repeaters; BMW Perf black grille; CSL reps; SSDD carbon diffuser; Monster Wrap black roof/clear front
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06-11-2020, 10:20 AM	#2
Efthreeoh General 17207 Rep 18,697 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	N52 is the same.
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06-29-2020, 05:27 PM	#3
Dormermike Captain 102 Rep 681 Posts Drives: Bmw f10 Join Date: Dec 2015 Location: Uk iTrader: (0)	N53 also iirc
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06-30-2020, 10:26 AM	#4
CTinline-six Hoonigan 6816 Rep 3,000 Posts Drives: '09 328i, '98 Wrangler Join Date: Dec 2016 Location: Connecticut iTrader: (0) Garage List 2009 BMW 328i N51 [0.00]	It seems to only be an issue for engines with higher HP, especially tuned engines. __________________ "Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should." -Dr. Ian Malcolm, Jurassic Park
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07-21-2020, 04:14 AM	#6
Js235 New Member 0 Rep 11 Posts Drives: BMW 335i N54 - ex-BMW 130i Join Date: Jan 2018 Location: Spain iTrader: (0)	I think N54 have same system
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