Service difficulty report · Sprag Clutch · Diamon DA20A1

Difficulty date
March 1, 2005
Submitted
April 1, 2005
Operation
General aviation
Make and model
Diamon DA20A1
Aircraft time
3,602 hours
Engine
Rotax ROTAX912F3
Propeller
Hofman HOV352F
Part
Sprag Clutch
Part number
852401
Condition
Loose
Location
Crankshaft
Component
Crankcase
Component part number
887911
Stage of operation
IN
How discovered
V
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

(CAN) ENG WAS FOUND TO HAVE SEVERAL OIL LEAKS AND HARD STARTING. DURING INSP IT WAS NOTED THAT CRANKCASE SEALANT WAS NOT IAW MFG REC. SEALANT HAD RUBBERY/SILICONE COMPOSITION AS OPPOSED TO APPEARANCE OF CORRECT SEALANT. DURING COLD STARTS, STARTING SPRAG CLUTCH WOULD SLIP. DURING TEARDOWN INSP, DISCOVERED THAT SPRAG CLUTCH HSG WAS ASSEMBLED USING INCORRECT RETAINING COMPOUND, ALLOWING HSG TO SLIPON CRANKSHAFT. SPRAG CLUTCH HSG WAS GALLED AND UNSERVICABLE, CRANKSHAFT SUSTAINED NO DAMAGE. INCORRECT CRANKCASE SEALANT ALLOWED MOVEMENT BETWEEN CRANKCASE HALVES CAUSING FRET DAMAGE, CASE DAMAGE. NOTE: INCORRECT SEALING COMPOUND AND THREAD LOCKING COMPOUND WAS FOUND TO HAVE BEEN USED THROUGHOUT ENGINE.

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