What was found
AFTER TAKEOFF, HAD ALL GEAR RETRACTED NOSE GEAR WAS SLOW BUT SHOWED NORMAL ( NO LIGHTS) AFTER APPROX 30 SECONDS RED NOSE LIGHT CAME ON. RAN CHECK LIST, CYCLED GEAR RED NOSE LIGHT REMAINED ON. NOISE LEVEL ALSO INDICATED THAT GEAR WAS NOT TOTALLY UP. GEAR WAS EXTENDED FOR NORMAL LANDING ( RTN BACK TO BOSTON ) INSPECTED NOSE GEAR AND DOORS NO TROUBLE FOUND. FOUND NOSE GEAR STRUT PROPERLY SERVICED. LUBED NOSE GEAR AS PRECATIONARY. REPLACED NOSE GEAR UP DOWN LOCK SENSORS PER MM. OPERATED NOSE GEAR UP/DOWN_SEVERAL CYCLES ALL INDICATIONS NORMAL.