The MMX Performance BMW S55 / N55 One-Piece Crank Hub Upgrade Kit is a precision-engineered solution designed to permanently eliminate one of the most well-documented failure points in BMW’s S55 and N55 engines. The factory three-piece crank hub relies on friction surfaces that can slip under load, leading to timing misalignment and, in severe cases, catastrophic engine damage.
The MMX one-piece crank hub upgrade replaces the OE multi-piece design with a fully integrated billet construction, eliminating the possibility of internal slippage. By removing the reliance on friction-based engagement, this system ensures consistent crankshaft timing and significantly improves long-term engine reliability under both factory and high-performance conditions.
Manufactured from billet EN36 steel and heat-treated with a 0.75mm case hardening, the MMX crank hub delivers exceptional strength, wear resistance, and durability. The kit includes a new crank bolt to ensure proper installation and clamping force, providing a complete and robust solution compared to the factory setup.
For enhanced security, the kit can be configured with an optional MMX capture plate. This additional component prevents crank bolt loosening caused by engine harmonics or vibration by mechanically locking the bolt in place, offering an extra layer of protection for tuned or aggressively driven vehicles.
Designed for both stock and modified engines, the MMX Performance BMW One-Piece Crank Hub Upgrade Kit is a proven reliability upgrade that eliminates risk at the source, providing confidence for daily driving, track use, and future performance builds.
Product Details
- MMX Performance one-piece crank hub upgrade kit for BMW S55 and N55 engines
- Eliminates factory three-piece friction-based hub design
- Prevents crank hub slip and timing misalignment
- Machined from billet EN36 steel with 0.75mm case hardening
- High-strength construction for extreme durability
- Includes new crank bolt for proper installation
- Optional capture plate available for additional security
- Designed for stock, tuned, and high-performance applications
- Direct-fit upgrade with no internal friction plates
Vehicle Applications
- BMW F80 M3
- BMW F82 / F83 M4
- BMW F87 M2
- BMW F87 M2 Competition / CS
- BMW F22 / F23 2 Series
- BMW F30 / F31 3 Series
- BMW F32 / F33 4 Series
Recommended Products
Notes
- SKU: MMR20-1001
- Designed and engineered in the UK
- Optional capture plate available for additional crank bolt security
- Recommended for both stock and tuned applications
- For high horsepower builds, consider upgraded 4-pin crank hub option
- Professional installation required