Kies Motorsports Crank Seal Guard, BMW N54/N55/S55

These are precision engineered with tight tolerances, based on factory specs. If you've had your seal replaced due to an engine repair, crank hub upgrade, etc, please ensure that the seal has been properly set and has a minimum depth of 3/8". Compatible with F series N55 and S55 engines.

The all-new Kies Crank Seal Guard is an inexpensive insurance policy to protect your very expensive BMW N54/N55 and even S55 from potential catastrophic engine failure! 

On the N54/N55 and S55, the accessory belt sits under some common leak areas in your car’s oil and coolant system. If you experience one of these leaks, what can happen is your accessory belt can start to walk off your crank pulley. Because of the design of the engine, tiny shards of rubber from your fraying belt can easily find their way through your crank seal. If this happens, these little pieces of the belt can get picked up by your timing chain and find their way into your valve cover and cause damage, and/or they can lodge themselves into your oil pickup, starving your engine of oil. Additionally, we’ve even seen cases where the belts snap, wrap themselves around your crank pulley and force the entire belt into the engine, through the crank seal! If either of these situations is to occur, you’ll be certainly looking at a costly new engine, which will cost thousands of dollars.

After seeing these devastating engine failures, we went to work to design a bulletproof solution to prevent this from happening! The Kies Crank Seal Guard is a precisely engineered piece of art, which acts to block belts and belt particles from making their way through the crank seal, by reducing the gap between the Kies Crank Seal Guard and the crank hub to just twenty thousandths of an inch, saving your engine! The Kies Crank Seal Guard also features self-centering technology, to ensure a perfect fit every single time.

The Kies Crank Seal Guard is machined out of a single piece of 6061 billet aluminum, to eliminate the chance of any welds snapping, it includes BMW Genuine Bolts and it’s proudly made in the USA!