What was found
WITH AUTOPILOT ENGAGED, TRIM CLACKER AUDIBLE MORE THAN NORMAL. AFTER DISENGAGING AUTOPILOT, WE DISCOVERED NEITHER YOKE PRIMARY TRIM SWITCH HAD ANY AUTHORITY, NO CAS MESSAGE. WE ENGAGED SECONDARY TRIM SYSTEM AND MADE A PRECAUTIONARY LANDING WITHOUT INCIDENT. [08-23-07] INSTALLED NEW MOTOR, CLUTCH AND BRAKE ASSY FOR HORIZONTAL STAB TRIM IAW 750 MM 27-40-00. OPS CKED GOOD. (NOTE REPLACED L/H PRIMARY).