What was found
NLG LANDING GEAR EXTENSION: CLIMBING THROUGH FL230 AT 280 KTS WE HEARD A LOUD BANG, FOLLOWED BY A MODERATE VIBRATION AND THE RED NOSE GEAR UNLOCK WAS FLICKERING ON AND OFF. ON DESCENT BACK TO DEPARTURE POINT THE THE GEAR SEEMED TO RETRACT BACK UP INTO THE WELL AND THE UNLOCK EXTINGUISHED. LANDING GEAR EXTENDED NORMALLY FOR LANDING. // SIGNOFF // JACKED THE AIRCRAFT AND MEASURED THE NLG STRUT EXTENSION TO BE 10.18". THIS IS OVER THE SPECIFICATION OF 9.75+/-.078". THE NOSE STRUT NEEDS TO BE RESEALED. (TALKED TO IAN JENKINS AT NETJETS AND NETJETS WILL LET US KNOW IF THEY DESIRE COMPLIANCE WITH SL680-32-08-- NLG STRUT SEAL IMPROVEMENT.) PERFORMED GEAR SWING AND NOTED THAT ROLLER IS ON EDGE OF UPLOCK HOOK. THE UPLOCK SWITCH MAY HAVE BEEN ADJUSTED TO MATCH THE GEAR AT PRESENT LENGTH AND SO WILL NEED TO BE READJUSTED ONCE THE NLG IS RESEALED. REMOVED LH NOSE WHEEL P/N 3-1538-1 S/N 0630 AND RH NOSE WHEEL P/N 3-1538-1 S/N 1036. WHILE REMOVING NOSE GEAR LOWER BARREL, FOUND ORFICE COMPLETELY UNSCREWED FROM LOWER END OF UPPER BARREL. REMOVED LOWER BARREL P/N 6742170-6 S/N 367 AND DISSEMBLED. REMOVED OLD SEALS AND CLEANED PARTS. IAW CE680CMM 32-20-01. REPLACED ALL SEALS AND REASSEMBLED NOSE STRUT. C/W SL680-32-08 NOSE LANDING GEAR STRUT SEAL IMPROVEMENT. REPLACED RETAINER NUT P/N 6742172-6 DUE TO PITTING AND WEAR(INCLUDED IN SEAL MOD KIT P/N 6742160-200). INSTALLED LOWER BARREL ASSEMBLY P/N 6742170-6 S/N 367 IAW CMM 32-20-01.SERVICED STRUT WITH NITROGEN AND 5606 HYDRAULIC FLUID IAW MM 12-20-32. CLEANED AND LUBED WHEEL BEARINGS. INSTALLED LH WHEEL P/N 3-1538-1 S/N 0630 AND RH WHEEL P/N 3-1538-1 S/N 1036. TORQUED AND SAFETIED AXLE NUTS. INSTALLED HUB CAPS. IAW MM 32-41-10. COMPLIED WITH STEPS 1 THROUGH 15 OF THE NLG UPLOCK SWITCH ADJUSTMENT IAW MM 32-60-00. NEED TO PERFORM THE MLG SYSTEM UPLOCK SWITCHES OPERATION AL CHECKCOMPLIED WITH.