Issues relating to the OE three-piece crank hub found in the S55 and N55 engine are unfortunately widely known. Thankfully, these issues are addressed with the MMR Performance one-piece billet crank hub.
The OE crank hub unit's friction material is well known to slip, causing the timing to alter enough that piston-to-valve contact can occur and, if not totally standard and within the warranty period, leaves owners with a very expensive repair bill.
We have developed this single-piece Crank Hub together with our optional capture plate to ensure owners have complete peace of mind, whether on an untuned factory car or equally for those that wish to increase the power and torque output without ever having to worry again. MMR Performance have engineered the most comprehensive solution on the market and at one of the most compelling price points.
Our crank hub is machined from billet EN36 steel that's been heat-treated with a 0.75mm case hardening, making it incredibly strong and durable. The one-piece design ensures the friction plates can no longer slip and with a new crank bolt (supplied with the crank hub) tightened appropriately, this alone delivers the transformational improvement in reliability versus the OE version.
Additionally, pairing the single piece crank hub with the optional MMR capture plate ensures complete peace of mind. A capture plate removes the possibility for the crank bolt to loosen with the engine's vibrations or harmonics.
