AN LJ45 CAPTAIN REPORTS ELEVATOR AND CONTROL YOKE ANOMALIES ON APPROACH; WITH THE YOKE MOVING 1 TO 2 INCHES FORE AND AFT WITH NO CORRESPONDING ELEVATOR MOVEMENT.

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CONFIGURING THE ACFT FOR APCH AND LAND; FLAPS 40 DEGS; GEAR DOWN; 5 NU; LEVEL FLT; N1 70%; AUTOPLT ON AND OFF; SPD DECREASING FROM 160-140 KTS THE YOKE OSCILLATES +/-1 INCH WITHOUT ANY ACFT PITCH CHANGE; BOTH AUTOPLT ON AND AUTOPLT OFF. PWR THROUGH SPD AND LOWERED NOSE; NORMAL FLT RESUMED; FURTHER FLT CHK CONFIRMED EVENT IN APCH AND LNDG CONFIGURING; CONSULTATIONS WITH MAINT AND MANUFACTURER REPRESENTATIVES; FOR TROUBLESHOOTING. NO EICAS OR ACFT WARNINGS OBSERVED; RECONFIGURED THE FLAPS 20 DEGS; GEAR DOWN; LEVEL FLT N1 70; DECREASING THROUGH 160 KTS ACFT YOKE PUMPED BACK AND FORTH; +/-2 INCHES; GREATER WITH DECREASING AIRSPD; ACFT PITCH DID NOT CHANGE WITH YOKE MOVEMENT; PWR UP AND LOWERED NOSE ACFT RECOVERED. MAINT STATED THAT THE MAIN ELEVATOR CABLE WAS OFF PULLEY AND WRAPPED AROUND ELEVATOR SERVO ALSO OVER THE SERVO CABLES AND WAS 45 LBS LESS THAN NORMAL CABLE TENSION. OP CHK FLT THE FOLLOWING DAY FAILED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THERE IS STILL SOME CONFUSION IN TROUBLESHOOTING THIS INCIDENT; AND MAINTENANCE IS UNSURE IF IT IS AN AUTOPILOT OR FLIGHT CONTROL ISSUE.