Service difficulty report · Bearing · Cessna 404

Difficulty date
December 12, 2005
Submitted
June 6, 2006
Operation
General aviation
Make and model
Cessna 404
Engine
Cont GTSIO520M
Propeller
Mcauly 3FF32C501
Part
Bearing
Condition
Collapsed
Location
Alternator
Component
Alternator · Prestolite
Component part number
ALV9510
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

RT ENG DRIVEN ALT FAILED. ALT DRIVE COUPLING SHEARED AND ALT FRONT BEARING COLLAPSED. RED ELASTOMER MAT`L FROM ALT DRIVE COUPLING AND MINOR METALLIC PARTICLES VISIBLE INTERNALLY THRU ALT ATTACHMENT PORT. ALT DISASSEMBLED AND INSPECTED. FRONT BEARING SERIOUSLY DETERIORATED. SEVERAL BALL BEARINGS MISSING, 2 SEVERELY DEFORMED AND REMAINDER SHOWING SIGNS OF DISTRESS. FRONT BEARING SEAL DEFORMED BY MIGRATION OF MISSING BALL BEARINGS THROUGH SEAL INTO ENG. ROTOR LOOSE DUE TO FRONT BEARING FAILURE AND HAD CONTACTED STATOR. A MIXTURE OF GREASE AND OIL WAS FOUND ADHERING TO INTERNAL SURFACE OF FRONT ALT HOUSING. GREASE/OIL MIXTURE EXHIBITED A PATTERN CONSISTENT WITH BEING FLUNG OUT OF ALT FRONT BEARING.

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