The crank hub on the high-powered BMW S55 is not keyed or locked in place. While this is not a departure from previous BMW engine designs, the S55 is such a fast revving, high power motor, in which under a variety of circumstances, the hub can be allowed to spin on the crank. As an interference-style engine, too much spin results in piston-to-valve contact, and an extremely expensive rebuild ($,$$$) or replacement ($$,$$$). While the specific parameters surrounding failure are not precisely known, one thing is clear: slippage causes severe engine damage. This slippage, or spinning, is not isolated to just DCT or just manual cars, just stock or just modified cars, nor does every car experience failure. It's just an expensive gamble to not address this point of failure.
Offering both a positively-located and securely-torqued fix, Gintani's one-piece crank hub is the one-and-done solution for S55 owners seeking peace of mind on their stock cars, all the way up to high horsepower monsters.
Machined at Gintani's facility in Los Angeles, California, this kit includes everything explicitly required to address the dangers of the factory crank hub: installation crank bolt, key hole drill bit and drill block, Gintani upgraded crank bolt, and most importantly: Gintani F8X One Piece Crank Hub.
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