SDR 98ZZZX4079

Service difficulty report · Crankshaft · Robsin R22

Difficulty date
October 16, 1998
Submitted
March 26, 2000
Operation
General aviation
Make and model
Robsin R22
Engine
Lyc O320B2C
Part
Crankshaft
Part number
LW17060
Condition
Out Of Tolerance
Location
Engine
Stage of operation
IN
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

CRANKSHAFT REMOVED FROM ENGINE AT TBO. JOURNALS REQUIRED GRINDING AND RENITRIDED DUE TO WEAR. INSPECTION OF GEAR COUNTERBORE PER AD 91-14-22 REVEALED DOWL HOLE HAD BEEN FACTORY REPAIRED BY INSTALLATION OF SLEEVE. TEXTRON LYCOMING SB 475 HAS NO DATA FOR SLEEVE REPAIRS OR INSPECTION. DAMAGE TO CRANKSHAFT COUNTERBORE ID AT PREVIOUS GEAR ASSY DUE TO RADIAL POSITION OF DOWEL BEING OUT OF TOLERANCE. THIS REPAIR STATION HAS NOTED SIMILAR PROBLEMS ON TWO OTHER CRANKSHAFTS OF THE SAME P/N THIS YEAR. LYC SB 4758 CONTAINS NO DATA FOR RADIAL OR ANGULAR POSITION OF DOWEL HOLE.