As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL 390 AIRPLANE EXPERIENCE A JOLT AND THE GEAR UNLOCK LIGHT ILLUMINATED WE SLOWED AND DESCENDED BELOW FL180, EXTENDED GEAR NORMALLY AND WITH EMERGENCY BLOW DOWN. REMOVED THE NOSE LANDING GEAR UPPER AND LOWER BARREL ASSEMBLIES, INSPECTED AND FOUND UPPER BARREL TO BE PITTED AND CORRODED. INSTALLED NEW UPPER BARREL IAW SRM CHAPTER 32-20-02.