As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW SELECTED GEAR UP AFTER LIFT OFF AND RECEIVED FLUCTUATING UP/BARBER POLE/UP/BARBER POLE/ETC WITH ACCOMPANYING AURAL AND VISUAL GEAR DISAGREE WARNINGS. EXTENDED GEAR MANUALLY AND LANDED AT NEAREST AIRPORT IN ACCORDANCE WITH QRH. MX FOUND HEAVY FILM OF GREASE AND DIRT ON PROX SWITCHES. CLEANED GREASE OFF. SERVICED STRUTS.