What was found
FLT 5268--DEPARTING ATL RETRACTED GEAR AND GOT A NOSE WHEEL DISAGREE WARNING MSG. COMPLIED WITH QRH AND PLANE WAS CHANGING PITCH AND CREW FELT THE NOSE WHEEL GEAR FLAPPING IN WIND. HYDRAULICS APPEARED NORMAL, CONTINUED WITH QRH AND PRIOR TO PULLING GEAR HANDLE THE GEAR CORRECTED ITSELF. LOWERED GEAR NORMALLY AND LANDED OVERWEIGHT AT 48000 LBS. EMERGENCY DECLARED, ACFT RETURNED AFTER T/O. REMOVED AND REPLACED NOSE GEAR SELECTOR VALVE IAW AMM 32-22-20. OPS CHECK GOOD. C/W OVERWEIGHT LANDING INSP IAW AMM 05-51-01 SP 625.