SDR 98ZZZX2698

Service difficulty report · Snap Ring

Difficulty date
April 21, 1998
Submitted
March 26, 2000
Operation
General aviation
Engine
Cont O470R
Part
Snap Ring
Part number
629104
Condition
Misinstalled
Location
Crankshaft
Stage of operation
IN
How discovered
O
Nature of condition
W
Precautionary procedure
K

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

What was found

THE ENGINE WHICH CONTAINED THESE PARTS WAS SHIPPED DIRECTLY FROM TCM AFTER REMANUFACTURE. UPON DISASSEMBLY, FOUND THE CRANKSHAFT COUNTERWEIGHT PIN SNAP RINGS WERE INSTALLED WITH THE SMOOTH ROUNDED SIDE TO THE OUTSIDE. THE O-470 OVERHAUL MANUAL (72-50-07 PARA D) SPECIFICALLY STATES THE RETAINING RING IS TO BE INSTALLED 'WITH THE FLAT OR ROUGH SIDE OF THE RETAIING RING TO THE OUTSIDE'. ALSO, ONE OF THE SNAP RINGS WAS NOT SEATED IN THE RETAINING RING GROOVE. THIS CONDITION, IF NOT DETECTED, WOULD CAUSE A CATASTROPHE.