What was found
AIRCRAFT TAXIED NORMALLY, AFTER ADVANCING THROTTLES & COMMENCING TAKEOFF ROLL, ACFT DEMONSTRATED SIGNIFICANT VIBRATION FELT IN NOSE WHEEL AREA & RT GEAR WELL. POSSIBLY TIRE OUT OF BALANCE. ACFT WAS ABORTED AT APPROX 80 KNOTS. DURING DECELERATION & BRAKING EVEN MORE VIBRATION WAS FELT. AT TAXI SPEED ACFT PERFORMED NORMALLY. INSPECTED AIRCRAFT TRIM TABS FOR CONDITION & SECURITY, CHECKED GOOD. JACKED ACFT AND INSPECTED MAIN & NOSE GEAR LINKEAGES, CHECKED GOOD. INSPECTED SHIMMY DAMPER FOR SERVICE AND INSTALLATION IAW AMM 32-41-02. CHECKED NORMAL. FOUND RT MAIN TIRE EXTREMELY OUT OF ROUND. REMOVED AND REPLACED RT MAIN WHELL AND TIRE ASSY IAW MM 32-41-01. NOSE TIRE ALSO OUT OF ROUND. REMOVED AND REPLACED NOSE WHEEL AND TIRE ASSY IAW MM 32-41-02. PERFORMED HIGH SPEED TAXI, OPS CHECKED NORMAL.