S5x Performance S55 4-Pin CrankhubBulletproof your S55 with the S5x Performance Pinned Crankhub. A must on all S55 engines, especially if you plan on tuning it! The stock hub is a known failure point in S55 engines. A failed hub that has spun will lead to incorrect engine timing which could potentially cause engine damage. The S5x Performance Crankhub is proven to prevent the hub from spinning. Our design incorporates a double locking, two piece assembly. Includes: S5x Performance 4