When I refer to these flywheels, I don't mean the brass weights on the motor that diesels use. I'm referring to the discs on the side of the transfer case that the side rods attach to. They turn and the side rods move back and forth in the cylinders but the driveshaft running front to rear in the transfer case does not turn, the driveshaft is square tubing with slip yokes like a Shay.