Failed crank hubs have been a common ailment of the N54 / N55 / S55 family for the last 15 years, leading to crankshaft spin, causing skipped timing and potentially catastrophic engine damage.

The VAC Motorsports 4 Pin Crank Hub is more exact than OEM due to precise engineering and careful CNC machining. The 4 pin design prevents the valve timing and oil pump chains from spinning independently, and mechanically securing the crank hub to the crank nose. Doing so keeps the entire assembly accurate and secure.

Via careful engineering and design, VAC was able to minimize the total assembly from three pieces to two by combining the hub and timing sprocket into a single machined unit. So long as the bolt is properly tightened to the crank, the timing sprocket will always be in sync with the crank.

1-piece crank hub/timing gear

Keyed oil pump gear

Genuine BMW crankshaft bolt

Drill bit 

Drill guide

VAC Crank Seal Guard