F80 F82 F83 F87 S55 pinned crank hub kit - RK Billet RKS55CRANKHUB

For F80, F82, F83 and F87 BMWs with the S55 engine: this RK Billet 4130 chromoly 4-pin crank hub stops hub spin dead. CNC machined, heat treated, laser scanned for OEM alignment.

• Prevents timing drift and crank hub rotation under hard use - proven to 750+bhp
• Includes precision drill bits for clean, repeatable installation
• Direct fit; no machining or modifications required
• OEM crank bolt not included - a new BMW unit is mandatory

Track-day ready, fast-road robust, daily-driver durable. Not an OEM replacement - a purpose-built upgrade.