As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKE OFF, MLG WOULD NOT RETRACT. DECLARED AN EMERGENCY AND RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS GROUNDED. REPLACED THE LANDING GEAR SELECTOR VALVE IAW AMM 32-31-51. SYSTEM OPS CHECKED NORMAL IAW AMM 32-32-00-710-801.