What was found
DURING TEST FLIGHT AFTER INSTALLATION OF BOOSTER PACK, LATERAL M/R CONTROL BECAME SPONGY/SLUGGISH, MUSHING AND SLOW TO RESPOND. LATERAL FEEDBACK IN CONTROLS. SHOP INSPECTION REVEALED BINDING IN SYS I AND SYS II LATERIAL CONTROL SERVO ACTUATORS OF BOOSTER PACK. SERVO VALVE BUSHINGS, PN MB1015DU, SUPPORTING SERVO VALVE COUPLING BOLTS, PN 105-46666.07, WERE FOUND BINDING CAUSING HIGH INPUT FORCES TO SERVO VALVE. CAUSE OF SUDDEN BUSHING TIGHTNESS IS UNKNOWN. BUSHINGS WERE BURNISHED TO REDUCE FRICTION ON COUPLING BOLTS TO NORMAL LIMITS. NOTE: LATERAL ACTUATORS SYMMETRY WAS OUT OF LIMITS AND RETURNED TO WITHIN LIMITS AFTER REPAIR WAS MADE BY BURNISHING TIGHT BUSHINGS.