Service difficulty report · Connecting Rod · Cessna 172N

Difficulty date
September 22, 2009
Submitted
December 1, 2009
Operation
General aviation
Make and model
Cessna 172N
Aircraft time
2,486 hours
Engine
Lyc O320H2AD
Part
Connecting Rod
Part number
78030
Condition
Mismanufactured
Location
Engine
Part time
363 hours
Stage of operation
IN
How discovered
V
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

(CAN) THE BOLT HOLE DID NOT HAVE SUFFICIENT CHAMFER TO FULLY ACCEPT THE BOLT. THERE IS A SERVICE BULLETIN ADDRESSING THIS ISSUE FOR THE OLDER PART NUMBER CONNECTING RODS. THIS NEWER PART NUMBER ROD IS SUPPOSED TO HAVE THIS LARGER CHAMFER INCORPORATED. INSUFFICIENT CHAMFER DOES NOT ALLOW THE BOLT TO SEAT FULLY AGAINST THE CONNECTING ROD. ADEQUATE TORQUE CANNOT BE ASSURED, AND THE RISK OF CONNECTING ROD BOLT FAILURE IS PRESENT. WE HAVE DISCOVERED THIS 2 TIMES PRIOR WITH NEW PART NUMBER CONNECTING RODS. (TC# 20091021003)

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