What was found
(CAN) ON TAKEOFF THE PILOT NOTICED SUBSTANTIAL AIRFRAME VIBRATION THAT DISSIPATED WHEN CLIMBING THROUGH 1000 AGL. SUSPECTED NOSE WHEEL/TIRE ASSY DISTRESS. THE FLIGHT WAS DIVERTED TO HOME BASE FOR PRECAUTIONARY MEASURES WHERE AN UNEVENTFUL LANDING OCCURRED. MAINTENANCE PERSONNEL DISCOVERED THE NOSE TIRE HAD AN INTERNAL BALANCE WEIGHT COME LOOSE AND WAS FREE TO MOVE ABOUT THE INSIDE THE WHEEL AND TIRE ASSY. THE BALANCE WEIGHT IS A 1.5 OZ RUBBER PATCH 5" BY 1.75".