When your wheel bearing service is done, the castle nut is the last thing standing between your hub and the road. The Lippert 122081 is a direct-replacement 1-inch spindle castle nut with six slots, engineered for Lippert-built RV trailer axles rated from 3,500 to 8,000 lbs. It cross-references Gulf Stream part 491BY7 and Jayco part 0323454, making it a go-to service part for a wide range of travel trailers and fifth-wheels.
Castle nuts (also called castellated nuts) are a critical safety component on trailer axle spindles. The six slots in the Lippert 122081 accept a cotter pin that locks the nut in position after it is torqued to spec, preventing the hub from backing off under load and vibration. Using the correct OEM-spec nut ensures the cotter pin holes in the spindle align properly.
This nut is sized for 1-inch spindle threads -- the standard diameter found on Lippert axles in the 3,500 to 8,000 lb capacity range. If your current nut is damaged, corroded, or was lost during a bearing repack, this is the correct replacement part.
Six evenly spaced slots accept a standard cotter pin to lock the nut against loosening under road vibration and load.
Compatible with Lippert axles rated 3,500 to 8,000 lbs -- covers a broad range of travel trailers, fifth-wheels, and toy haulers.
Direct replacement for Gulf Stream part 491BY7 and Jayco part 0323454. Fits Lippert-sourced axle assemblies across multiple OEM brands.
Backed by Lippert's limited 1-year manufacturer warranty against defects in materials and workmanship.
Lippert Components supplies axle assemblies to the majority of towable RV manufacturers in North America. If your trailer uses a Lippert axle -- which includes a large share of Coachmen, Forest River, Gulf Stream, Heartland, Jayco, Keystone, and many other brands -- this castle nut is very likely the correct service part for your spindle.
Always verify your spindle thread diameter (1 inch) before ordering. A quick look at the existing nut or a caliper measurement of the spindle threads confirms fitment before you commit.
Castle nuts are considered a wear-inspection item during any wheel bearing repack. Best practice is to inspect the nut for thread damage and slot deformation each time the hub is removed. Replace the cotter pin every time -- never reuse a bent or spread pin. Torque the nut to the axle manufacturer's specification before inserting the new cotter pin.
One (1) Lippert 122081 1-inch 6-slot spindle castle nut. Cotter pin and bearing grease are not included and must be sourced separately.
Customers replacing this castle nut typically also need: a new cotter pin (3/16-inch diameter is common for 1-inch spindles), inner and outer wheel bearings, bearing grease or bearing buddy caps, and a spindle washer. Check your axle service manual for the exact bearing cone and cup numbers for your specific axle rating.