As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TORQUE SPLIT ON TAKE OFF. REDUCED COLLECTIVE, AND TORQUE MATCHED. TORQUE SPLIT AGAIN IN CRUISE FLIGHT. #1 TORQUE WAS 12-15% HIGHER AND FLUCTUATING. TORQUES HELD THAT SPLIT, THEN # 1 WOULD FLUCTUATE. UNABLE TO MATCH TORQUES. DIVERTED BACK TO BASE WITH PATIENT ON BOARD. BASE WAS AS CLOSE OF AN OPTION AS ANYWHERE ELSE. REDUCED #1 TWIST GRIP TO MATCH TORQUES AND PERFORMED RUNNING LANDING. CHANGED OUT N2 POTENTIOMETER DUE TO TORQUE SPLIT IN FLIGHT WITH GUIDANCE FROM AMM 76-11-00, 8-61. PERFORMED N2 CHECKS, GROUND RUNS AND FCF.