What was found
GEAR DISAGREE WARNING MESSAGE ON DEPARTURE, RIGHT MAIN GEAR AFFECTED. WARNING MESSAGE CLEARED BY QRH WITH GEAR INDICATING DOWN AND THREE GREEN, FLIGHT COMPLETED WITH GEAR EXTENDED AT OR BELOW 200KIAS WITH NO FURTHER ABNORMALITIES. (FLIGHT 5323) COMPLIED WITH TROUBLE-SHOOTING PER CRJ 200 FIM 32-60-09. INTERROGATED PSEU AND FLAGGED S18 PROX SENSOR FAR, RIGHT MLG. INSPECTED PROX SENSOR AND FOUND UPLOCK ASSY. TARGET LOOSE AND CAUSING OUT OF RANGE FOR SENSOR. SECURED RIGHT MLG UPLOCK TARGET. REFERENCE CMM 32-30-15. ADJUSTED RIGHT MLG UPLOCK SENSOR. REFERENCE AMM 32-61-05. PERFORMED GEAR EXTENSION/RETRACTION WITH NO ABNORMALITIES NOTED. NO GEAR DISAGREE WARNING MESSAGES NOTED. OPS CHECKS, GOOD. REFERENCE AMM 32-30-00.