What was found
AFTER TAKEOFF, NOSE GEAR UNSAFE LIGHT BEGAN FLICKERING. RECYCLED GEAR THEN GOT STEADY RIGHT MAIN GEAR UNSAFE LIGHT. PERFORMED ABNORMAL PROCEDURES, FELT STRONG VIBRATION AT 210 KTS. RETURNED TO PNS. REPLACED BUSHING, TARGET SPRING AND ADJUSTED UPLATCH ROLLER CLEARANCE. OPS CHECKED GOOD IAW DC9 MM 32-31-4.