What was found
ON FINAL, GEAR HANDLE PLACED DOWN & PRIMARY INDICATIONS WERE ALL THREE RED AND ALL THREE GEAR SHOWED RED ON CONFIG PAGE. RETRACTED GEAR & RAN QRH. ALL GEAR THEN EXTENDED NORMALLY. SUSPECT GEAR HANDLE NOT ALL THE WAY IN ON FINAL. ALL INDICATIONS OPS CK NORMAL REF PER MM 32-60-00-0. FOUND LARGE AMOUNT OF DUST IN LANDING GEAR LEVER ASSY. GEAR HANDLE SLIDER WAS SLOW TO RETRACT, CAUSING THE GEAR UNSAFE LIGHTS(RED)TO STAY RED. CLEANED DUST/DEBRIS FROM SLIDER AND SWITCHES FROM LEVER ASSY. LUBED SLIDER ON GEAR HANDLE. INSTALLED GEAR PINS AND CHECKED POSITION LIGHT WITH GEAR HANDLE- ALL CHECKS GOOD. GEAR PINS REMOVED.