What was found
DURING TAKEOFF, PF NOTICED AN UNUSUAL AMOUNT OF FORCE TO ROTATE ACFT. DURING CLIMB, HAND FLYING, APPROX 3X AMOUNT OF USUAL FORCE REQUIRED TO MOVE ACFT IN PITCH AXIS. WHEN AP1 IN USE, AP FUNCTIONED NORMAL. ATTEMPT MADE TO SWITCH TO AP2, AP2 WAS NOT AVAIL. DURING LANDING, WHEN AP DISENGAGED, EXTRA FORCE REQUIRED TO MOVE PITCH AXIS. BELOW 500, FELT AS IF AP MADE INPUTS CAUSING EXCESS FORCE TO OVERRIDE. AN EMERGENCY DECLARED INTO MEM. REF TSI 27-30/1447 FOR ELEVATOR FORCE CHECKS, SYSTEM INSPECTIONS, AND LUBRICATION. REF TSI 22-10/1449 & WRI 22-10/1450 FOR OTHER MAINTENANCE PEROFRMED. REMOVED AND REPLACED RT INBD ELEVATOR SOLENOID VALVE S2-827.