Service difficulty report · Rocker Shaft

Difficulty date
September 7, 2007
Submitted
September 26, 2007
Operation
General aviation
Aircraft
N977CC
Engine
Cont O200*
Part
Rocker Shaft
Part number
654375
Condition
Loose
Location
Cylinder
Component
Cylinder
Component part number
O200
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

IAW OWNERS REQUEST, REMOVED ALL (4) ROCKER COVERS TO INSPECT THE ROCKER SHAFT AND SET SCREWS. AFTER REMOVING THE ROCKER COVERS. FOUND ALL(4) SET SCREWS LOOSE AND ALL (4) SHAFTS MOVED TOWARD THE INTAKE SIDE OF THE BOSSES. NONE HAVE CUT THE ROCKER COVERS YET, IN ANOTHER 20 HOURS OR SO THEY WOULD. NOTE: THE NEW ENGINE HAVE A FLAT CUT INTO THE ROCKER SHAFT, AND A SET SCREW IN THE CENTER BOSS, TO RETAIN THE SHAFT. ALSO, THE SHAFT IS SHARP ON THE END, UNLIKE THE OLD STYLE, AND HAVE A CUT MARK ACROSS THE END OF THE SHAFT FOR USE IN ALINING THE FLAT FOR THE SET SCREW. THE SET SCREW IS A MS51963-64, AND USES NO LOCKTITE, OR MECHANICAL TYPE LOCK. THE FLAT IN THE ROCKER SHAFT IS NOT DEEP ENOUGH TO PROVIDE ADEQUATE L