As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHX - EN ROUTE PHX TO ORD LEFT MAIN GEAR WOULD NOT RETRACT AFTER TAKEOFF. RETURNED PHX AND LANDED WITHOUT INCIDENT. FOUND LEFT GEAR BUNGEE CYLINDER ROD END BROKEN. REMOVED AND REPLACED LEFT GEAR CYLINDER. ACCOMPLISHED GEAR SWING AND LUBE. SYSTEM GROUND CHECKED NORMAL OPERATION.