Dana Spicer part number 4221668 is a self-locking screw used in off-highway axle applications. This is a genuine OEM hardware fastener sold individually. The self-locking thread design is intended to resist loosening under vibration and load conditions typical of off-highway driveline and axle assemblies. Pro Gear and Transmission stocks genuine Dana Spicer parts for professional buyers. Not certain this is the right part for your application? Call us to confirm proper fit before ordering.Interchanges:Allison Off Highway LY4221668FeaturesGenuine Dana Spicer OEM hardware fastenerPart number 4221668Self-locking thread design resists loosening under vibrationIntended for off-highway axle and driveline applicationsSold as individual unit (each)Tech SpecsPart Number: 4221668Application: Off-highway axle and drivelineUnit of Measure: Each