Failed crank hubs have been reported over several different BMW engines, including N54, N55, and S55, leading to valid worries about the integrity of the stock hub/bolt/sprocket assembly. If the crankshaft bolt becomes loose and the hub is allowed to spin it will cause the engine valve timing to skip or jump, potentially causing widespread engine damage.
This locking crank hub bolt kit puts an added layer of security to the crankshaft bolt. By locking the crankshaft bolt in place, it cannot become loose and back itself out. This bolt capture kit for N55 and S55 engines uses the 8 bolts from the vibration damper to stop the main crank bolt from coming loose. It weighs only 1.3 ounces and, in most cases, does not even require the bolt to be removed to install. Unlike other solutions no major disassembly of the engine is required. The best time to install this would be during a major tune-up such as a drive belt change or other service where the drive belt has to be removed.
Note 1: fits with Genuine BMW original crankshaft bolt only, not an aftermarket or other brand crankshaft bolt. A new bolt is not required.
Note 2: Vargas reports that a small number of original factory crank bolts will not line up with the capture kit. Their recommendation is to tighten the crankshaft bolt further until the hex of the bolt head aligns with the hex of the capture plate. Because of the extremely high torque spec and procedure for tightening the crank bolt, professional install is recommended if this rare adjustment is needed.
BMW Fitments:
1 Series
E82 / E88 (08-13) > 135i N55 (11-13)
E82 / E88 (08-13) > 135is N55 (11-13)
2 Series
F22 / F23 (2014-2021) > M235i
F22 / F23 (2014-2021) > M235i xDrive
F22 / F23 (2014-2021) > M235i-Racing
F22 / F23 (2014-2021) > M240i-Racing
2 Series
F87 (2016-2021) > M2 CS Racing
F87 (2016-2021) > M2 Competition S55 (2019+)
F87 (2016-2021) > M2 N55 (2016-2018)
3 Series
E90 / E91 / E92 / E93 (06-13) > 335i N55 (11-13)
E90 / E91 / E92 / E93 (06-13) > 335xi N55 (11-13)
3 Series
F30 / F31 / F34 (2012-2019) > 335i
F30 / F31 / F34 (2012-2019) > 335i xDrive
3 Series
F80 (2015-2018) > M3 (2015-2018)
4 Series
F32 / F33 / F36 (14-20) > 435i
F32 / F33 / F36 (14-20) > 435i xDrive
4 Series
F82 / F83 (2015-2020) > M4 (2015-2020)
F82 / F83 (2015-2020) > M4 GT4
F82 / F83 (2015-2020) > M4 GTS
5 Series
F10 / F11 (11-16) > 535i
F10 / F11 (11-16) > 535i xDrive
6 Series
F12 / F13 (12-18) > 640i
7 Series
F01 / F02 (2009-2015) > 740Li
F01 / F02 (2009-2015) > 740i
X1 Series
E84 X1 (2013-2015) > X1 35i xDrive
X3 Series
F25 X3 (2011-2017) > X3 xDrive35i
X4 Series
F26 X4 (2015-2018) > X4 35i xDrive
F26 X4 (2015-2018) > X4 M40i xDrive
X5 Series
E70 X5 (07-13) > X5 xDrive35i N55
X5 Series
F15 X5 (2014-2018) > X5 sDrive35i
F15 X5 (2014-2018) > X5 xDrive35i
X6 Series
E71 X6 (2008-2014) > X6 xDrive35i N55 (10-13)
X6 Series
F16 X6 (2015-2019) > X6 sDrive35i
F16 X6 (2015-2019) > X6 xDrive35i