As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING REPLACEMENT OF V-BELT SET IT WAS FOUND THAT THE FANSHAFT ASSY HAD CORROSION AND PITTING ON THE TAPERED SHAFT. CORROSION AND PITTING WAS ALSO NOTED ON THE TAPERED BORE OF THE FANWHEEL ASSY PN: D174-2. FANSHAFT AND FANWHEEL REPLACED.