As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT NOTICED AFTER LANDING GEAR WAS SELECTED UP, GEAR WARNING LIGHT AND HYDRAULIC ON LIGHT WERE ON. SELECTED GEAR DOWN, HAD THREE GREEN DOWN AND LOCKED INDICATION. WENT BACK TO ORIGINAL AIRPORT AND LANDED UNEVENTFULLY. JACKED AIRCRAFT SWUNG GEAR AND FOUND THAT RIGHT MAIN LANDING GEAR OLIO STRUT WAS NOT FULLY EXTENDED, MISALIGNING THE UPLOCK ROLLER TO SWITCH. REPLACED OLIO STRUT WITH A SERVICEABLE UNIT.