What was found
SMOKE FROM THE NR 2 MAIN TIRE DURING PREFLIGHT. SMOKE WHITE IN COLOR AND WAS VISIBLE FOR 20 MINUTES. INSTALLED GEAR DOWNLOCK PINS. RAISED LT MLG AND INSPECTED NR 2 TIRE FOR DEFECTS, NONE FOUND. PERFORMED GVI OF LT MLG WHEELS, TIRES AND BRAKES. NO DEFECTS FOUND. INSPECTED AREA OF MLG AND LT NACELLE FOR FLUID LEAKS. NO LEAKS FOUND. OPERATED AIRCRAFT BRAKES. OPERATION APPEARED NORMAL. REMOVED ALL GEAR DOWN LOCK PINS.