Precision Dynamics Crank Seal Guard (N5X/S55)A common issue seen on the N5X S55 engines is how fragile the front rubber crank seal is when your belt either tears or slips, or a pulley breaks. With nothing protecting the crank seal, the belt can break the seal and get sucked inside your motor. When this happens, you must remove the subframe and oil pan to extract any belt debris that entered the engine. In severe cases, the belt may get stuck onto the timing chain and thrown upwards into the