As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF THE GEAR WOULD NOT RETRACT, THE AUTO SPOILER AND AUTO THROTTLES DISCONNECTED. AIR RETURN TO DTW. MAINTENANCE UPON INSPECTION NOTED RT MLG STRUT FLAT. REPLACED RT SHOCK ABSORBER IAW TASK CARD 3210-503. PERFORMED LANDING GEAR FUNCTIONAL CHECKS IAW RJ-85 M/M 32-30-00 501. ALL CHECKS GOOD.