As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RUDDER FAILS BACKLASH CHECK FOR HYDRAULIC SYSTEM 1 & 2 PER CRJ 900 AMM TASK 27-21-00-720-803. MAXIMUM ALLOWABLE BACKLASH ON HYDRAULIC SYSTEM 1 IS 0.250". HIGHEST TESTED VALUE WAS 0.395". MAX ALLOWABLE BEARING BACKLASH VALUE IS 0.120", MEASURED VALUE WAS 0.132". MAXIMUM ALLOWABLE BACKLASH ON HYDRAULIC SYSTEM 2 IS 0.250", AND HIGHEST TESTED VALUE WAS 0.365". WORN SPHERICAL BEARINGS IN HINGE FITTINGS 2 AND 3 IS THE CAUSE.