5150 AutoSport Upgraded Crank Hub, BMW S55

The BMW S55 Engine's Crank Hub is a critical component, linking the crankshaft, water pump, power steering pump, and alternator. OEM hub failure occurs as the crank hub separates from the crankshaft, spinning independently of the crankshaft. This failure is not only well-known among technicians and enthusiasts, but a catastrophic failure, causing severe engine damage. 

The Problem

OEM Failure is mainly due to the design of the crank hub assembly; the OEM crankshaft's splined end is press-fit into the crank hub. As the assembly ages and wears, the connection between the hub and crank weakens, leading to slippage or complete separation.

As the crank hub separates from the crank, the timing chain loses its synchronization with the crankshaft and camshaft, causing piston-to-valve contact and severe internal engine damage. 

The 5150 Solution

Improved Materials: Our Upgraded Crank Hub is machined from 4340 Billet Steel to ensure strength and endurance, then heat treated to ensure longevity. 

4-Pin Design: The 5150 Crank Hub uses a 4-pin attachment style, distributing load across (4) points rather than the OEM single point press-fit. 

Included Crank Bolt: To further reduce the risk of slipping, spinning, or failure, our Crank Hub Upgrade includes a genuine BMW Crank Bolt, providing additional attachment reinforcement. 

Precision Machining: Ensuring precise fitment and alignment, the 5150 Upgraded Crank Hub is engineered and manufactured to tighter tolerances than OEM hubs. This also functions to maintain optimal engine timing and performance.

Power-Ready: 5150 Upgraded Crank Hubs are designed and manufactured with high performance, high boost applications. While they can be used as simply as a preventative OEM-replacement, they are also ready for the high heat and high stresses of high horsepower performance engine builds and aggressive driving applications.