What was found
SELECTED GEAR UP, WITH A SAFE INDICATION, A LOUD VIBRATION AND NOISE INCREASING WITH AIRSPEED. SELECTED GEAR DOWN. SAFE INDICATION. NO NOISE, SELECTED GEAR UP, SAME NOISE AND VIBRATION. SELECTED GEAR DOWN SAFE INDICATION AND LANDED. THE AIRCRAFT WAS GROUNDED. REMOVED AND REPLACED THE LT & RT FORWARD LINK IAW AMM 32-22-01. PERFORMED A NLG & DOORS TEST IAW AMM 32-20-00. GROUND CHECKED NORMAL.