The MMX Single Piece Crank Hub Upgrade is the ultimate solution to the well-documented crank hub failures affecting BMW’s S55 and N55 engines. Designed with a 4-pin dowelled single-piece design, this upgrade eliminates the risk of the factory three-piece hub slipping – a known cause of catastrophic engine failure in M2, M3, M4, and N55-powered models.
CNC-machined in the UK from heat-treated billet EN36 steel with 0.75mm case hardening, the hub offers exceptional strength and durability. Four aerospace-grade precision dowels mechanically lock the hub to the crankshaft, preventing any possibility of movement. The kit also includes a brand new OE crank bolt for complete security.
To simplify installation, the MMX kit comes complete with a bolt-on drilling guide jig, location bolt, and HSS rolled drill bit – ensuring professional fitment is accurate, safe, and straightforward. For those seeking the ultimate level of security, the hub is also available with an optional capture plate.
4 aerospace-grade precision dowels for a secure mechanical lock
Machined from heat-treated billet EN36 steel with case hardening
Supplied with a new OE crank bolt
Includes full installation jig, drilling guide, and HSS drill bit
Optional capture plate for additional protection
Designed and manufactured in the UK
The ultimate reliability upgrade for BMW S55 and N55 engines
Compatibility:
BMW 1 Series (F20/F21) – M135i (N55)
BMW 2 Series (F22/F23, F87) – M235i, OG M2 (N55), M2 Competition (S55)
BMW 3 Series (F30/F31, F80) – 335i (N55), M3 (S55)
BMW 4 Series (F32/F33, F82) – 435i (N55), M4 (S55)
Model Years: 2011–2021
Protect your BMW from crank hub failure with the MMX S55 & N55 Single Piece Crank Hub Upgrade – precision-engineered for strength, durability, and complete peace of mind.
