What was found
SEVERE VIBRATION AT APPROXIMATELY 60 KNOTS DURING TAKEOFF. YAW DAMPER DISCONNECTED AND NR 1 ADC FAILED. ABORTED TAKE OFF IAW ETA PROCEDURE. FOUND NLG SQUAT SWITCH OUT OF ADJUST. ADJUSTED SWITCH AS REQUIRED IAW 750 MM 32-60-00. SERVICED NLG STRUT IAW 750 MM 12-10-38. RETORQUED NLG TORQUE LINK BOLTS IAW 750 MM 32-20-00. ADJUSTED NLG CASTER IAW 750 MM 32-30-03. REPLACED NLG ACT ELASTOMERS IAW 750 SB 32-43. RETORQUED NLG TRUNNION MOUNT BOLTS IAW 750 MM 32-20-00. REMOVED AND REPLACED L/R NLG WHEEL ASSY IAW 750 MM 32-41-00. PERFORMED GEAR SWING IAW 750 MM 32-20-01. ALL OPS CHECK GOOD. TAXI CHECK GOOD. C/W DAMPER LINEAR ACT TEST IAW 750 MM 27-24-00. C/W NR 1 MADC OPS CHECK IAW 750 MM 34-11-08. ALL OPS CHECK GOOD.