What was found
AFTER TAKEOFF RED GEAR UNLOCK LIGHT WILL NOT GO OUT WHEN GEAR HANDLE IS SELECTED UP. CYCLED GEAR 2 TIMES WITH NO CHANGE, ACCOMPLISHED AIR TURNBACK AND LANDED WITHOUT INCIDENTS. ACCOMPLISHED GEAR SWING AND FOUND NOSE GEAR NOT LOCKING, MEASURED STRUT EXTENSION AND FOUND TO BE OVER EXTENDED. REMOVED PISTON ASSEMBLY FROM TRUNNION AND FOUND UPPER BEARING CAP NOT FULLY SEATED ON PISTON. RETORQUED CAP AND ASSEMBLED STRUT AND SERVICED. SWUNG GEAR & CHECKED GOOD, ALL WORK DONE IAW CESSNA 560XL COMPONENT MM CHAPTER 32-20-01, OPS AND LEAK CHECK GOOD.