As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE POWER SECTION WAS REPORTED AS HARD TO ROTATE. UPON DISASSEMBLY, FOUND PROP SHAFT AND SLEEVE WAS GALLED IN SUCH A WAY THAT IT COULD NOT ROTATE FREELY. IT HAS BEEN DETERMINED THE GALLING OCCURRED DUE TO FUEL OIL HEATER CONTAMINATING THE OIL SYSTEM WITH FUEL.