What was found
ON SHORT FINAL, NOSE GEAR WAS MAKING A THUMPING SOUND. EXECUTED GO AROUND, CYCLED LG, & HEARD SAME THUMPING SOUND. APPROX 15 - 20 THUMPS IN 15 MINUTES. BOTH NOSE TIRES WORN TO LIMITS, DECLARED EMER. R & R LT NLG WHEEL ASSEMBLY & RT NLG WHEEL ASSEMBLY IAW WC 32-700-17.