What was found
IN CLIMB ABOVE FL340-FL370 THE NR 1 ENGINE WOULD NOT MAINTAIN CLIMB N1 OF 93.1% THE MAX IT MAINTAINED AT THOSE ALTITUDES WAS 91.8 WHICH DECREASED TO A MAX OF 91.4 AT FL370. N1 EGI WAS 796 VS N2 OF 699; N2'S WERE 96.6 AND 91.2 RESPECTIVELY. AT CRUISE POWER THE READINGS WERE N1S 85.8 & 85.9, EGTS 698 AND 640, N2S 920 AND 88.2 FUEL FLOW 2500 AND 2400. FUEL FLOW WAS NEVER MORE THAN 100 PPH ON NR 1 ENG VS NR 2. T/S FOUND VBV DRIVE MOTOR SHAFT SHEARED. REMOVED AND REPLACED BOTH FAN GEAR HYD MOTOR AND BLEED VALVE PER AMM.