The Fabco 688-0633 (also listed as 6880633) is a genuine OEM hex self-locking nut with a 1-1/4-18 thread specification. Fabco is a recognized manufacturer of transfer case, steerable drive axle, and power takeoff components, and this nut is sourced directly through their OEM parts channel. Self-locking hex nuts are used in high-vibration drivetrain assemblies where standard fasteners can back off under load, making thread specification and locking engagement critical to proper assembly. Sold by Pro Gear and Transmission. Call us to confirm this is the correct fastener for your application before ordering.
Features
Genuine Fabco OEM part, sourced through official OEM channel
Thread size: 1-1/4-18
Hex self-locking design resists loosening under vibration
Part number: 688-0633 or 6880633
Sold by Pro Gear and Transmission
