Description
When pushing your BMW S55 or N55 engine beyond 700 horsepower, crank hub failure is a real threat — and MMX Performance’s 4-Pin One-Piece Crank Hub Upgrade is the bulletproof solution you need.
This complete kit eliminates the notorious slippage and potential catastrophic engine failure caused by the OEM three-piece crank hub design. With a fully machined, hardened one-piece hub and aerospace-grade 4-pin locking system, this upgrade locks your crank precisely and permanently in place — with no possibility of rotation or misalignment under extreme loads.
Key Features:
- Fits S55 and N55 engines (e.g., F80 M3, F82 M4, M2 Competition, M235i, 335i, 435i)
- Recommended for high-power builds over 700HP
- One-piece CNC-machined crank hub from billet EN36 steel
- 0.75mm case-hardened for maximum strength and wear resistance
- 4 precision dowel pins lock hub to crankshaft for zero slippage
- Includes brand new OE crank bolt
- Optional Capture Plate for added belt retention and security
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Supplied with complete installation jig:
- Bolt-on guide plate
- Precision drill bit
- Location hardware for safe and accurate pin drilling
- UK engineered and manufactured
Why You Need This Upgrade:
The factory S55/N55 crank hub design relies solely on friction to stay in place — a risky flaw that shows its limits quickly under tuned or track-driven conditions. A single slip can mean lost timing, valve/piston contact, and full engine rebuild.
MMX's solution solves this permanently by mechanically locking the crank hub to the crankshaft using four dowel pins and a hardened one-piece structure. This ensures perfect timing integrity, even under intense high-RPM and high-boost abuse.
Installation Note:
Due to the precision machining and crankshaft modifications required, professional installation is mandatory. The included jig and tools ensure the safest and most accurate process possible.
Complete Peace of Mind for Tuned BMWs
If you're serious about power — or simply want to bulletproof your build — the MMX 4-Pin Crank Hub Kit is essential insurance against catastrophic failure, trusted by performance shops and racers alike.
