As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FINAL APPROACH, PILOT NOTICED THE COLLECTIVE BECAME STIFF AND THE PEDALS HAD A RATCHET FEEL TO THEM. THE PILOT DECIDED TO ABORT THE APPROACH AND DIVERTED FOR AN EMERGENCY LANDING. THE APPROACH AND LANDING UNEVENTFUL. ON INSPECTION AND TROUBLESHOOTING, FOUND THE LT HYD FILTER DIRTY. THE FILTER REPLACED, AND THE ACFT RETURNED TO SERVICE.