QU10535 Special Mounting Nut for New Process Transfer Cases. Hardened, 3/8" SAE Fine Thread Nut has an attached rotating washer to facilitate precise tightening of the nut without gouging the mounting adapter. Genuine OEM part is expensive, but probably provides the best retention of any nut type. Made in U.S.A.
For lower cost alternatives, see our Hardware and Fasteners Web Page for QU95058 SAE Flat Washer, QU95047 Flat Washer, and QU95035 Locknut. Sold individually, order 6 per vehicle.
For extra security against loosening, I always use medium strength Threadlocker with these Nuts (S9978 or S24200).
1989-1993 NP205 Transfer Cases
1994-2002 NP241DLD and NP241DHD Transfer Cases