What was found
AIRCRAFT TOOK OFF, GEAR RETRACTED, ALL NORMAL. AT ABOUT 40K FT, CAPTAIN HEARD A LOUD THUD & THE NOSE GEAR UNLOCK INDICATION CAME ON. CREW REPORTED RESISTANCE FROM THE NOSE SECTION. THEY DID A QUICK DECENT TO 10K FT & CYCLED THE GEAR. THEY CYCLED DOWN & GOT 3 GREEN & CYCLED BACK UP WITH NO UNLOCK INDICATIONS. TURNED BACK TO SBA, EXTENDED GEAR ON FINAL, 3 GREEN WITH NO ISSUES UPON LANDING. UPON TROUBLESHOOTING FOUND NOSE STRUT PRESSURE AT 2.6 PSI WHICH CAUSED THE GEAR TO NOT FULLY EXTEND AND COMPLETLEY ENGAGE THE UP-LOCK HOOK. ALSO FOUND THE NOSE UPPER STRUT UNDER SERVICED. SERVICED NOSE GEAR IAW AMM 12-10-38. PERFORMED SEVERAL GEAR RETRACTIONS WITH ALL CHECKS SATISFACTORY.